A flaw was found in the Linux kernel Traffic Control (TC) subsystem. Using a specific networking configuration (redirecting egress packets to ingress using TC action "mirred") a local unprivileged user could trigger a CPU soft lockup (ABBA deadlock) when the transport protocol in use (TCP or SCTP) does a retransmission, resulting in a denial of service condition.
A deadlock flaw was found in the Linux kernel’s BPF subsystem. This flaw allows a local user to potentially crash the system.
A denial of service vulnerability was found in tipc_crypto_key_revoke in net/tipc/crypto.c in the Linux kernel’s TIPC subsystem. This flaw allows guests with local user privileges to trigger a deadlock and potentially crash the system.
A denial of service vulnerability due to a deadlock was found in sctp_auto_asconf_init in net/sctp/socket.c in the Linux kernel’s SCTP subsystem. This flaw allows guests with local user privileges to trigger a deadlock and potentially crash the system.
In the Linux kernel, the following vulnerability has been resolved: tracing: Build event generation tests only as modules The kprobes and synth event generation test modules add events and lock (get a reference) those event file reference in module init function, and unlock and delete it in module exit function. This is because those are designed for playing as modules. If we make those modules as built-in, those events are left locked in the kernel, and never be removed. This causes kprobe event self-test failure as below. [ 97.349708] ------------[ cut here ]------------ [ 97.353453] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:2133 kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.357106] Modules linked in: [ 97.358488] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.9.0-g699646734ab5-dirty #14 [ 97.361556] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 97.363880] RIP: 0010:kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.365538] Code: a8 24 08 82 e9 ae fd ff ff 90 0f 0b 90 48 c7 c7 e5 aa 0b 82 e9 ee fc ff ff 90 0f 0b 90 48 c7 c7 2d 61 06 82 e9 8e fd ff ff 90 <0f> 0b 90 48 c7 c7 33 0b 0c 82 89 c6 e8 6e 03 1f ff 41 ff c7 e9 90 [ 97.370429] RSP: 0000:ffffc90000013b50 EFLAGS: 00010286 [ 97.371852] RAX: 00000000fffffff0 RBX: ffff888005919c00 RCX: 0000000000000000 [ 97.373829] RDX: ffff888003f40000 RSI: ffffffff8236a598 RDI: ffff888003f40a68 [ 97.375715] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 97.377675] R10: ffffffff811c9ae5 R11: ffffffff8120c4e0 R12: 0000000000000000 [ 97.379591] R13: 0000000000000001 R14: 0000000000000015 R15: 0000000000000000 [ 97.381536] FS: 0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000 [ 97.383813] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 97.385449] CR2: 0000000000000000 CR3: 0000000002244000 CR4: 00000000000006b0 [ 97.387347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 97.389277] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 97.391196] Call Trace: [ 97.391967] <TASK> [ 97.392647] ? __warn+0xcc/0x180 [ 97.393640] ? kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.395181] ? report_bug+0xbd/0x150 [ 97.396234] ? handle_bug+0x3e/0x60 [ 97.397311] ? exc_invalid_op+0x1a/0x50 [ 97.398434] ? asm_exc_invalid_op+0x1a/0x20 [ 97.399652] ? trace_kprobe_is_busy+0x20/0x20 [ 97.400904] ? tracing_reset_all_online_cpus+0x15/0x90 [ 97.402304] ? kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.403773] ? init_kprobe_trace+0x50/0x50 [ 97.404972] do_one_initcall+0x112/0x240 [ 97.406113] do_initcall_level+0x95/0xb0 [ 97.407286] ? kernel_init+0x1a/0x1a0 [ 97.408401] do_initcalls+0x3f/0x70 [ 97.409452] kernel_init_freeable+0x16f/0x1e0 [ 97.410662] ? rest_init+0x1f0/0x1f0 [ 97.411738] kernel_init+0x1a/0x1a0 [ 97.412788] ret_from_fork+0x39/0x50 [ 97.413817] ? rest_init+0x1f0/0x1f0 [ 97.414844] ret_from_fork_asm+0x11/0x20 [ 97.416285] </TASK> [ 97.417134] irq event stamp: 13437323 [ 97.418376] hardirqs last enabled at (13437337): [<ffffffff8110bc0c>] console_unlock+0x11c/0x150 [ 97.421285] hardirqs last disabled at (13437370): [<ffffffff8110bbf1>] console_unlock+0x101/0x150 [ 97.423838] softirqs last enabled at (13437366): [<ffffffff8108e17f>] handle_softirqs+0x23f/0x2a0 [ 97.426450] softirqs last disabled at (13437393): [<ffffffff8108e346>] __irq_exit_rcu+0x66/0xd0 [ 97.428850] ---[ end trace 0000000000000000 ]--- And also, since we can not cleanup dynamic_event file, ftracetest are failed too. To avoid these issues, build these tests only as modules.
In the Linux kernel, the following vulnerability has been resolved: ext4: fix uninitialized ratelimit_state->lock access in __ext4_fill_super() In the following concurrency we will access the uninitialized rs->lock: ext4_fill_super ext4_register_sysfs // sysfs registered msg_ratelimit_interval_ms // Other processes modify rs->interval to // non-zero via msg_ratelimit_interval_ms ext4_orphan_cleanup ext4_msg(sb, KERN_INFO, "Errors on filesystem, " __ext4_msg ___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state) if (!rs->interval) // do nothing if interval is 0 return 1; raw_spin_trylock_irqsave(&rs->lock, flags) raw_spin_trylock(lock) _raw_spin_trylock __raw_spin_trylock spin_acquire(&lock->dep_map, 0, 1, _RET_IP_) lock_acquire __lock_acquire register_lock_class assign_lock_key dump_stack(); ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10); raw_spin_lock_init(&rs->lock); // init rs->lock here and get the following dump_stack: ========================================================= INFO: trying to register non-static key. The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator. CPU: 12 PID: 753 Comm: mount Tainted: G E 6.7.0-rc6-next-20231222 #504 [...] Call Trace: dump_stack_lvl+0xc5/0x170 dump_stack+0x18/0x30 register_lock_class+0x740/0x7c0 __lock_acquire+0x69/0x13a0 lock_acquire+0x120/0x450 _raw_spin_trylock+0x98/0xd0 ___ratelimit+0xf6/0x220 __ext4_msg+0x7f/0x160 [ext4] ext4_orphan_cleanup+0x665/0x740 [ext4] __ext4_fill_super+0x21ea/0x2b10 [ext4] ext4_fill_super+0x14d/0x360 [ext4] [...] ========================================================= Normally interval is 0 until s_msg_ratelimit_state is initialized, so ___ratelimit() does nothing. But registering sysfs precedes initializing rs->lock, so it is possible to change rs->interval to a non-zero value via the msg_ratelimit_interval_ms interface of sysfs while rs->lock is uninitialized, and then a call to ext4_msg triggers the problem by accessing an uninitialized rs->lock. Therefore register sysfs after all initializations are complete to avoid such problems.
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix overrunning reservations in ringbuf The BPF ring buffer internally is implemented as a power-of-2 sized circular buffer, with two logical and ever-increasing counters: consumer_pos is the consumer counter to show which logical position the consumer consumed the data, and producer_pos which is the producer counter denoting the amount of data reserved by all producers. Each time a record is reserved, the producer that "owns" the record will successfully advance producer counter. In user space each time a record is read, the consumer of the data advanced the consumer counter once it finished processing. Both counters are stored in separate pages so that from user space, the producer counter is read-only and the consumer counter is read-write. One aspect that simplifies and thus speeds up the implementation of both producers and consumers is how the data area is mapped twice contiguously back-to-back in the virtual memory, allowing to not take any special measures for samples that have to wrap around at the end of the circular buffer data area, because the next page after the last data page would be first data page again, and thus the sample will still appear completely contiguous in virtual memory. Each record has a struct bpf_ringbuf_hdr { u32 len; u32 pg_off; } header for book-keeping the length and offset, and is inaccessible to the BPF program. Helpers like bpf_ringbuf_reserve() return `(void *)hdr + BPF_RINGBUF_HDR_SZ` for the BPF program to use. Bing-Jhong and Muhammad reported that it is however possible to make a second allocated memory chunk overlapping with the first chunk and as a result, the BPF program is now able to edit first chunk's header. For example, consider the creation of a BPF_MAP_TYPE_RINGBUF map with size of 0x4000. Next, the consumer_pos is modified to 0x3000 /before/ a call to bpf_ringbuf_reserve() is made. This will allocate a chunk A, which is in [0x0,0x3008], and the BPF program is able to edit [0x8,0x3008]. Now, lets allocate a chunk B with size 0x3000. This will succeed because consumer_pos was edited ahead of time to pass the `new_prod_pos - cons_pos > rb->mask` check. Chunk B will be in range [0x3008,0x6010], and the BPF program is able to edit [0x3010,0x6010]. Due to the ring buffer memory layout mentioned earlier, the ranges [0x0,0x4000] and [0x4000,0x8000] point to the same data pages. This means that chunk B at [0x4000,0x4008] is chunk A's header. bpf_ringbuf_submit() / bpf_ringbuf_discard() use the header's pg_off to then locate the bpf_ringbuf itself via bpf_ringbuf_restore_from_rec(). Once chunk B modified chunk A's header, then bpf_ringbuf_commit() refers to the wrong page and could cause a crash. Fix it by calculating the oldest pending_pos and check whether the range from the oldest outstanding record to the newest would span beyond the ring buffer size. If that is the case, then reject the request. We've tested with the ring buffer benchmark in BPF selftests (./benchs/run_bench_ringbufs.sh) before/after the fix and while it seems a bit slower on some benchmarks, it is still not significantly enough to matter.
In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: allocate dummy checksums for zoned NODATASUM writes Shin'ichiro reported that when he's running fstests' test-case btrfs/167 on emulated zoned devices, he's seeing the following NULL pointer dereference in 'btrfs_zone_finish_endio()': Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f] CPU: 4 PID: 2332440 Comm: kworker/u80:15 Tainted: G W 6.10.0-rc2-kts+ #4 Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020 Workqueue: btrfs-endio-write btrfs_work_helper [btrfs] RIP: 0010:btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs] RSP: 0018:ffff88867f107a90 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff893e5534 RDX: 0000000000000011 RSI: 0000000000000004 RDI: 0000000000000088 RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed1081696028 R10: ffff88840b4b0143 R11: ffff88834dfff600 R12: ffff88840b4b0000 R13: 0000000000020000 R14: 0000000000000000 R15: ffff888530ad5210 FS: 0000000000000000(0000) GS:ffff888e3f800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f87223fff38 CR3: 00000007a7c6a002 CR4: 00000000007706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? die_addr+0x46/0x70 ? exc_general_protection+0x14f/0x250 ? asm_exc_general_protection+0x26/0x30 ? do_raw_read_unlock+0x44/0x70 ? btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs] btrfs_finish_one_ordered+0x5d9/0x19a0 [btrfs] ? __pfx_lock_release+0x10/0x10 ? do_raw_write_lock+0x90/0x260 ? __pfx_do_raw_write_lock+0x10/0x10 ? __pfx_btrfs_finish_one_ordered+0x10/0x10 [btrfs] ? _raw_write_unlock+0x23/0x40 ? btrfs_finish_ordered_zoned+0x5a9/0x850 [btrfs] ? lock_acquire+0x435/0x500 btrfs_work_helper+0x1b1/0xa70 [btrfs] ? __schedule+0x10a8/0x60b0 ? __pfx___might_resched+0x10/0x10 process_one_work+0x862/0x1410 ? __pfx_lock_acquire+0x10/0x10 ? __pfx_process_one_work+0x10/0x10 ? assign_work+0x16c/0x240 worker_thread+0x5e6/0x1010 ? __pfx_worker_thread+0x10/0x10 kthread+0x2c3/0x3a0 ? trace_irq_enable.constprop.0+0xce/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Enabling CONFIG_BTRFS_ASSERT revealed the following assertion to trigger: assertion failed: !list_empty(&ordered->list), in fs/btrfs/zoned.c:1815 This indicates, that we're missing the checksums list on the ordered_extent. As btrfs/167 is doing a NOCOW write this is to be expected. Further analysis with drgn confirmed the assumption: >>> inode = prog.crashed_thread().stack_trace()[11]['ordered'].inode >>> btrfs_inode = drgn.container_of(inode, "struct btrfs_inode", \ "vfs_inode") >>> print(btrfs_inode.flags) (u32)1 As zoned emulation mode simulates conventional zones on regular devices, we cannot use zone-append for writing. But we're only attaching dummy checksums if we're doing a zone-append write. So for NOCOW zoned data writes on conventional zones, also attach a dummy checksum.
In the Linux kernel, the following vulnerability has been resolved: netrom: Fix a memory leak in nr_heartbeat_expiry() syzbot reported a memory leak in nr_create() [0]. Commit 409db27e3a2e ("netrom: Fix use-after-free of a listening socket.") added sock_hold() to the nr_heartbeat_expiry() function, where a) a socket has a SOCK_DESTROY flag or b) a listening socket has a SOCK_DEAD flag. But in the case "a," when the SOCK_DESTROY flag is set, the file descriptor has already been closed and the nr_release() function has been called. So it makes no sense to hold the reference count because no one will call another nr_destroy_socket() and put it as in the case "b." nr_connect nr_establish_data_link nr_start_heartbeat nr_release switch (nr->state) case NR_STATE_3 nr->state = NR_STATE_2 sock_set_flag(sk, SOCK_DESTROY); nr_rx_frame nr_process_rx_frame switch (nr->state) case NR_STATE_2 nr_state2_machine() nr_disconnect() nr_sk(sk)->state = NR_STATE_0 sock_set_flag(sk, SOCK_DEAD) nr_heartbeat_expiry switch (nr->state) case NR_STATE_0 if (sock_flag(sk, SOCK_DESTROY) || (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) sock_hold() // ( !!! ) nr_destroy_socket() To fix the memory leak, let's call sock_hold() only for a listening socket. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with Syzkaller. [0]: https://syzkaller.appspot.com/bug?extid=d327a1f3b12e1e206c16
In the Linux kernel, the following vulnerability has been resolved: ipv6: prevent possible NULL dereference in rt6_probe() syzbot caught a NULL dereference in rt6_probe() [1] Bail out if __in6_dev_get() returns NULL. [1] Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cb: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000658-0x000000000000065f] CPU: 1 PID: 22444 Comm: syz-executor.0 Not tainted 6.10.0-rc2-syzkaller-00383-gb8481381d4e2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:rt6_probe net/ipv6/route.c:656 [inline] RIP: 0010:find_match+0x8c4/0xf50 net/ipv6/route.c:758 Code: 14 fd f7 48 8b 85 38 ff ff ff 48 c7 45 b0 00 00 00 00 48 8d b8 5c 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 19 RSP: 0018:ffffc900034af070 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90004521000 RDX: 00000000000000cb RSI: ffffffff8990d0cd RDI: 000000000000065c RBP: ffffc900034af150 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: 000000000000000a R13: 1ffff92000695e18 R14: ffff8880244a1d20 R15: 0000000000000000 FS: 00007f4844a5a6c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31b27000 CR3: 000000002d42c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> rt6_nh_find_match+0xfa/0x1a0 net/ipv6/route.c:784 nexthop_for_each_fib6_nh+0x26d/0x4a0 net/ipv4/nexthop.c:1496 __find_rr_leaf+0x6e7/0xe00 net/ipv6/route.c:825 find_rr_leaf net/ipv6/route.c:853 [inline] rt6_select net/ipv6/route.c:897 [inline] fib6_table_lookup+0x57e/0xa30 net/ipv6/route.c:2195 ip6_pol_route+0x1cd/0x1150 net/ipv6/route.c:2231 pol_lookup_func include/net/ip6_fib.h:616 [inline] fib6_rule_lookup+0x386/0x720 net/ipv6/fib6_rules.c:121 ip6_route_output_flags_noref net/ipv6/route.c:2639 [inline] ip6_route_output_flags+0x1d0/0x640 net/ipv6/route.c:2651 ip6_dst_lookup_tail.constprop.0+0x961/0x1760 net/ipv6/ip6_output.c:1147 ip6_dst_lookup_flow+0x99/0x1d0 net/ipv6/ip6_output.c:1250 rawv6_sendmsg+0xdab/0x4340 net/ipv6/raw.c:898 inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_write_iter+0x4b8/0x5c0 net/socket.c:1160 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6b6/0x1140 fs/read_write.c:590 ksys_write+0x1f8/0x260 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f
In the Linux kernel, the following vulnerability has been resolved: s390/mm: Fix VM_FAULT_HWPOISON handling in do_exception() There is no support for HWPOISON, MEMORY_FAILURE, or ARCH_HAS_COPY_MC on s390. Therefore we do not expect to see VM_FAULT_HWPOISON in do_exception(). However, since commit af19487f00f3 ("mm: make PTE_MARKER_SWAPIN_ERROR more general"), it is possible to see VM_FAULT_HWPOISON in combination with PTE_MARKER_POISONED, even on architectures that do not support HWPOISON otherwise. In this case, we will end up on the BUG() in do_exception(). Fix this by treating VM_FAULT_HWPOISON the same as VM_FAULT_SIGBUS, similar to x86 when MEMORY_FAILURE is not configured. Also print unexpected fault flags, for easier debugging. Note that VM_FAULT_HWPOISON_LARGE is not expected, because s390 cannot support swap entries on other levels than PTE level.
In the Linux kernel, the following vulnerability has been resolved: firmware: cs_dsp: Prevent buffer overrun when processing V2 alg headers Check that all fields of a V2 algorithm header fit into the available firmware data buffer. The wmfw V2 format introduced variable-length strings in the algorithm block header. This means the overall header length is variable, and the position of most fields varies depending on the length of the string fields. Each field must be checked to ensure that it does not overflow the firmware data buffer. As this ia bugfix patch, the fixes avoid making any significant change to the existing code. This makes it easier to review and less likely to introduce new bugs.
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix signedness bug in sdma_v4_0_process_trap_irq() The "instance" variable needs to be signed for the error handling to work.
In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix kernel bug on rename operation of broken directory Syzbot reported that in rename directory operation on broken directory on nilfs2, __block_write_begin_int() called to prepare block write may fail BUG_ON check for access exceeding the folio/page size. This is because nilfs_dotdot(), which gets parent directory reference entry ("..") of the directory to be moved or renamed, does not check consistency enough, and may return location exceeding folio/page size for broken directories. Fix this issue by checking required directory entries ("." and "..") in the first chunk of the directory in nilfs_dotdot().
In the Linux kernel, the following vulnerability has been resolved: ibmvnic: Add tx check to prevent skb leak Below is a summary of how the driver stores a reference to an skb during transmit: tx_buff[free_map[consumer_index]]->skb = new_skb; free_map[consumer_index] = IBMVNIC_INVALID_MAP; consumer_index ++; Where variable data looks like this: free_map == [4, IBMVNIC_INVALID_MAP, IBMVNIC_INVALID_MAP, 0, 3] consumer_index^ tx_buff == [skb=null, skb=<ptr>, skb=<ptr>, skb=null, skb=null] The driver has checks to ensure that free_map[consumer_index] pointed to a valid index but there was no check to ensure that this index pointed to an unused/null skb address. So, if, by some chance, our free_map and tx_buff lists become out of sync then we were previously risking an skb memory leak. This could then cause tcp congestion control to stop sending packets, eventually leading to ETIMEDOUT. Therefore, add a conditional to ensure that the skb address is null. If not then warn the user (because this is still a bug that should be patched) and free the old pointer to prevent memleak/tcp problems.
In the Linux kernel, the following vulnerability has been resolved: tty: add the option to have a tty reject a new ldisc ... and use it to limit the virtual terminals to just N_TTY. They are kind of special, and in particular, the "con_write()" routine violates the "writes cannot sleep" rule that some ldiscs rely on. This avoids the BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659 when N_GSM has been attached to a virtual console, and gsmld_write() calls con_write() while holding a spinlock, and con_write() then tries to get the console lock.
In the Linux kernel, the following vulnerability has been resolved: USB: class: cdc-wdm: Fix CPU lockup caused by excessive log messages The syzbot fuzzer found that the interrupt-URB completion callback in the cdc-wdm driver was taking too long, and the driver's immediate resubmission of interrupt URBs with -EPROTO status combined with the dummy-hcd emulation to cause a CPU lockup: cdc_wdm 1-1:1.0: nonzero urb status received: -71 cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625] CPU#0 Utilization every 4s during lockup: #1: 98% system, 0% softirq, 3% hardirq, 0% idle #2: 98% system, 0% softirq, 3% hardirq, 0% idle #3: 98% system, 0% softirq, 3% hardirq, 0% idle #4: 98% system, 0% softirq, 3% hardirq, 0% idle #5: 98% system, 1% softirq, 3% hardirq, 0% idle Modules linked in: irq event stamp: 73096 hardirqs last enabled at (73095): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline] hardirqs last enabled at (73095): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994 hardirqs last disabled at (73096): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (73096): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (73048): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (73048): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582 softirqs last disabled at (73043): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588 CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Testing showed that the problem did not occur if the two error messages -- the first two lines above -- were removed; apparently adding material to the kernel log takes a surprisingly large amount of time. In any case, the best approach for preventing these lockups and to avoid spamming the log with thousands of error messages per second is to ratelimit the two dev_err() calls. Therefore we replace them with dev_err_ratelimited().
In the Linux kernel, the following vulnerability has been resolved: i2c: lpi2c: Avoid calling clk_get_rate during transfer Instead of repeatedly calling clk_get_rate for each transfer, lock the clock rate and cache the value. A deadlock has been observed while adding tlv320aic32x4 audio codec to the system. When this clock provider adds its clock, the clk mutex is locked already, it needs to access i2c, which in return needs the mutex for clk_get_rate as well.
In the Linux kernel, the following vulnerability has been resolved: NFSv4: Fix memory leak in nfs4_set_security_label We leak nfs_fattr and nfs4_label every time we set a security xattr.
In the Linux kernel, the following vulnerability has been resolved: firmware: cs_dsp: Use strnlen() on name fields in V1 wmfw files Use strnlen() instead of strlen() on the algorithm and coefficient name string arrays in V1 wmfw files. In V1 wmfw files the name is a NUL-terminated string in a fixed-size array. cs_dsp should protect against overrunning the array if the NUL terminator is missing.
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix responder length checking for UD request packets According to the IBA specification: If a UD request packet is detected with an invalid length, the request shall be an invalid request and it shall be silently dropped by the responder. The responder then waits for a new request packet. commit 689c5421bfe0 ("RDMA/rxe: Fix incorrect responder length checking") defers responder length check for UD QPs in function `copy_data`. But it introduces a regression issue for UD QPs. When the packet size is too large to fit in the receive buffer. `copy_data` will return error code -EINVAL. Then `send_data_in` will return RESPST_ERR_MALFORMED_WQE. UD QP will transfer into ERROR state.
In the Linux kernel, the following vulnerability has been resolved: bcachefs: Fix sb_field_downgrade validation - bch2_sb_downgrade_validate() wasn't checking for a downgrade entry extending past the end of the superblock section - for_each_downgrade_entry() is used in to_text() and needs to work on malformed input; it also was missing a check for a field extending past the end of the section
In the Linux kernel, the following vulnerability has been resolved: iio: temperature: mlx90635: Fix ERR_PTR dereference in mlx90635_probe() When devm_regmap_init_i2c() fails, regmap_ee could be error pointer, instead of checking for IS_ERR(regmap_ee), regmap is checked which looks like a copy paste error.
In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: wext: add extra SIOCSIWSCAN data check In 'cfg80211_wext_siwscan()', add extra check whether number of channels passed via 'ioctl(sock, SIOCSIWSCAN, ...)' doesn't exceed IW_MAX_FREQUENCIES and reject invalid request with -EINVAL otherwise.
In the Linux kernel, the following vulnerability has been resolved: MIPS: Octeon: Add PCIe link status check The standard PCIe configuration read-write interface is used to access the configuration space of the peripheral PCIe devices of the mips processor after the PCIe link surprise down, it can generate kernel panic caused by "Data bus error". So it is necessary to add PCIe link status check for system protection. When the PCIe link is down or in training, assigning a value of 0 to the configuration address can prevent read-write behavior to the configuration space of peripheral PCIe devices, thereby preventing kernel panic.
In the Linux kernel, the following vulnerability has been resolved: udp: Set SOCK_RCU_FREE earlier in udp_lib_get_port(). syzkaller triggered the warning [0] in udp_v4_early_demux(). In udp_v[46]_early_demux() and sk_lookup(), we do not touch the refcount of the looked-up sk and use sock_pfree() as skb->destructor, so we check SOCK_RCU_FREE to ensure that the sk is safe to access during the RCU grace period. Currently, SOCK_RCU_FREE is flagged for a bound socket after being put into the hash table. Moreover, the SOCK_RCU_FREE check is done too early in udp_v[46]_early_demux() and sk_lookup(), so there could be a small race window: CPU1 CPU2 ---- ---- udp_v4_early_demux() udp_lib_get_port() | |- hlist_add_head_rcu() |- sk = __udp4_lib_demux_lookup() | |- DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk)); `- sock_set_flag(sk, SOCK_RCU_FREE) We had the same bug in TCP and fixed it in commit 871019b22d1b ("net: set SOCK_RCU_FREE before inserting socket into hashtable"). Let's apply the same fix for UDP. [0]: WARNING: CPU: 0 PID: 11198 at net/ipv4/udp.c:2599 udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599 Modules linked in: CPU: 0 PID: 11198 Comm: syz-executor.1 Not tainted 6.9.0-g93bda33046e7 #13 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599 Code: c5 7a 15 fe bb 01 00 00 00 44 89 e9 31 ff d3 e3 81 e3 bf ef ff ff 89 de e8 2c 74 15 fe 85 db 0f 85 02 06 00 00 e8 9f 7a 15 fe <0f> 0b e8 98 7a 15 fe 49 8d 7e 60 e8 4f 39 2f fe 49 c7 46 60 20 52 RSP: 0018:ffffc9000ce3fa58 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8318c92c RDX: ffff888036ccde00 RSI: ffffffff8318c2f1 RDI: 0000000000000001 RBP: ffff88805a2dd6e0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0001ffffffffffff R12: ffff88805a2dd680 R13: 0000000000000007 R14: ffff88800923f900 R15: ffff88805456004e FS: 00007fc449127640(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc449126e38 CR3: 000000003de4b002 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 PKRU: 55555554 Call Trace: <TASK> ip_rcv_finish_core.constprop.0+0xbdd/0xd20 net/ipv4/ip_input.c:349 ip_rcv_finish+0xda/0x150 net/ipv4/ip_input.c:447 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0x16c/0x180 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0xb3/0xe0 net/core/dev.c:5624 __netif_receive_skb+0x21/0xd0 net/core/dev.c:5738 netif_receive_skb_internal net/core/dev.c:5824 [inline] netif_receive_skb+0x271/0x300 net/core/dev.c:5884 tun_rx_batched drivers/net/tun.c:1549 [inline] tun_get_user+0x24db/0x2c50 drivers/net/tun.c:2002 tun_chr_write_iter+0x107/0x1a0 drivers/net/tun.c:2048 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x76f/0x8d0 fs/read_write.c:590 ksys_write+0xbf/0x190 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x41/0x50 fs/read_write.c:652 x64_sys_call+0xe66/0x1990 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x4b/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fc44a68bc1f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 e9 cf f5 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 3c d0 f5 ff 48 RSP: 002b:00007fc449126c90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000004bc050 RCX: 00007fc44a68bc1f R ---truncated---
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Validate ff offset This adds sanity checks for ff offset. There is a check on rt->first_free at first, but walking through by ff without any check. If the second ff is a large offset. We may encounter an out-of-bound read.
In the Linux kernel, the following vulnerability has been resolved: powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06 Johan reported the below crash with test_bpf on ppc64 e5500: test_bpf: #296 ALU_END_FROM_LE 64: 0x0123456789abcdef -> 0x67452301 jited:1 Oops: Exception in kernel mode, sig: 4 [#1] BE PAGE_SIZE=4K SMP NR_CPUS=24 QEMU e500 Modules linked in: test_bpf(+) CPU: 0 PID: 76 Comm: insmod Not tainted 5.14.0-03771-g98c2059e008a-dirty #1 NIP: 8000000000061c3c LR: 80000000006dea64 CTR: 8000000000061c18 REGS: c0000000032d3420 TRAP: 0700 Not tainted (5.14.0-03771-g98c2059e008a-dirty) MSR: 0000000080089000 <EE,ME> CR: 88002822 XER: 20000000 IRQMASK: 0 <...> NIP [8000000000061c3c] 0x8000000000061c3c LR [80000000006dea64] .__run_one+0x104/0x17c [test_bpf] Call Trace: .__run_one+0x60/0x17c [test_bpf] (unreliable) .test_bpf_init+0x6a8/0xdc8 [test_bpf] .do_one_initcall+0x6c/0x28c .do_init_module+0x68/0x28c .load_module+0x2460/0x2abc .__do_sys_init_module+0x120/0x18c .system_call_exception+0x110/0x1b8 system_call_common+0xf0/0x210 --- interrupt: c00 at 0x101d0acc <...> ---[ end trace 47b2bf19090bb3d0 ]--- Illegal instruction The illegal instruction turned out to be 'ldbrx' emitted for BPF_FROM_[L|B]E, which was only introduced in ISA v2.06. Guard use of the same and implement an alternative approach for older processors.
In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Fix ufshcd_abort_one racing issue When ufshcd_abort_one is racing with the completion ISR, the completed tag of the request's mq_hctx pointer will be set to NULL by ISR. Return success when request is completed by ISR because ufshcd_abort_one does not need to do anything. The racing flow is: Thread A ufshcd_err_handler step 1 ... ufshcd_abort_one ufshcd_try_to_abort_task ufshcd_cmd_inflight(true) step 3 ufshcd_mcq_req_to_hwq blk_mq_unique_tag rq->mq_hctx->queue_num step 5 Thread B ufs_mtk_mcq_intr(cq complete ISR) step 2 scsi_done ... __blk_mq_free_request rq->mq_hctx = NULL; step 4 Below is KE back trace. ufshcd_try_to_abort_task: cmd at tag 41 not pending in the device. ufshcd_try_to_abort_task: cmd at tag=41 is cleared. Aborting tag 41 / CDB 0x28 succeeded Unable to handle kernel NULL pointer dereference at virtual address 0000000000000194 pc : [0xffffffddd7a79bf8] blk_mq_unique_tag+0x8/0x14 lr : [0xffffffddd6155b84] ufshcd_mcq_req_to_hwq+0x1c/0x40 [ufs_mediatek_mod_ise] do_mem_abort+0x58/0x118 el1_abort+0x3c/0x5c el1h_64_sync_handler+0x54/0x90 el1h_64_sync+0x68/0x6c blk_mq_unique_tag+0x8/0x14 ufshcd_err_handler+0xae4/0xfa8 [ufs_mediatek_mod_ise] process_one_work+0x208/0x4fc worker_thread+0x228/0x438 kthread+0x104/0x1d4 ret_from_fork+0x10/0x20
In the Linux kernel, the following vulnerability has been resolved: ACPICA: Revert "ACPICA: avoid Info: mapping multiple BARs. Your kernel is fine." Undo the modifications made in commit d410ee5109a1 ("ACPICA: avoid "Info: mapping multiple BARs. Your kernel is fine.""). The initial purpose of this commit was to stop memory mappings for operation regions from overlapping page boundaries, as it can trigger warnings if different page attributes are present. However, it was found that when this situation arises, mapping continues until the boundary's end, but there is still an attempt to read/write the entire length of the map, leading to a NULL pointer deference. For example, if a four-byte mapping request is made but only one byte is mapped because it hits the current page boundary's end, a four-byte read/write attempt is still made, resulting in a NULL pointer deference. Instead, map the entire length, as the ACPI specification does not mandate that it must be within the same page boundary. It is permissible for it to be mapped across different regions.
In the Linux kernel, the following vulnerability has been resolved: powerpc/eeh: avoid possible crash when edev->pdev changes If a PCI device is removed during eeh_pe_report_edev(), edev->pdev will change and can cause a crash, hold the PCI rescan/remove lock while taking a copy of edev->pdev->bus.
In the Linux kernel, the following vulnerability has been resolved: ext4: fix slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists() We can trigger a slab-out-of-bounds with the following commands: mkfs.ext4 -F /dev/$disk 10G mount /dev/$disk /tmp/test echo 2147483647 > /sys/fs/ext4/$disk/mb_group_prealloc echo test > /tmp/test/file && sync ================================================================== BUG: KASAN: slab-out-of-bounds in ext4_mb_find_good_group_avg_frag_lists+0x8a/0x200 [ext4] Read of size 8 at addr ffff888121b9d0f0 by task kworker/u2:0/11 CPU: 0 PID: 11 Comm: kworker/u2:0 Tainted: GL 6.7.0-next-20240118 #521 Call Trace: dump_stack_lvl+0x2c/0x50 kasan_report+0xb6/0xf0 ext4_mb_find_good_group_avg_frag_lists+0x8a/0x200 [ext4] ext4_mb_regular_allocator+0x19e9/0x2370 [ext4] ext4_mb_new_blocks+0x88a/0x1370 [ext4] ext4_ext_map_blocks+0x14f7/0x2390 [ext4] ext4_map_blocks+0x569/0xea0 [ext4] ext4_do_writepages+0x10f6/0x1bc0 [ext4] [...] ================================================================== The flow of issue triggering is as follows: // Set s_mb_group_prealloc to 2147483647 via sysfs ext4_mb_new_blocks ext4_mb_normalize_request ext4_mb_normalize_group_request ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc ext4_mb_regular_allocator ext4_mb_choose_next_group ext4_mb_choose_next_group_best_avail mb_avg_fragment_size_order order = fls(len) - 2 = 29 ext4_mb_find_good_group_avg_frag_lists frag_list = &sbi->s_mb_avg_fragment_size[order] if (list_empty(frag_list)) // Trigger SOOB! At 4k block size, the length of the s_mb_avg_fragment_size list is 14, but an oversized s_mb_group_prealloc is set, causing slab-out-of-bounds to be triggered by an attempt to access an element at index 29. Add a new attr_id attr_clusters_in_group with values in the range [0, sbi->s_clusters_per_group] and declare mb_group_prealloc as that type to fix the issue. In addition avoid returning an order from mb_avg_fragment_size_order() greater than MB_NUM_ORDERS(sb) and reduce some useless loops.
In the Linux kernel, the following vulnerability has been resolved: bluetooth/l2cap: sync sock recv cb and release The problem occurs between the system call to close the sock and hci_rx_work, where the former releases the sock and the latter accesses it without lock protection. CPU0 CPU1 ---- ---- sock_close hci_rx_work l2cap_sock_release hci_acldata_packet l2cap_sock_kill l2cap_recv_frame sk_free l2cap_conless_channel l2cap_sock_recv_cb If hci_rx_work processes the data that needs to be received before the sock is closed, then everything is normal; Otherwise, the work thread may access the released sock when receiving data. Add a chan mutex in the rx callback of the sock to achieve synchronization between the sock release and recv cb. Sock is dead, so set chan data to NULL, avoid others use invalid sock pointer.
In the Linux kernel, the following vulnerability has been resolved: ppp: reject claimed-as-LCP but actually malformed packets Since 'ppp_async_encode()' assumes valid LCP packets (with code from 1 to 7 inclusive), add 'ppp_check_packet()' to ensure that LCP packet has an actual body beyond PPP_LCP header bytes, and reject claimed-as-LCP but actually malformed data otherwise.
In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: Lock wiphy in cfg80211_get_station Wiphy should be locked before calling rdev_get_station() (see lockdep assert in ieee80211_get_station()). This fixes the following kernel NULL dereference: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050 Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=0000000003001000 [0000000000000050] pgd=0800000002dca003, p4d=0800000002dca003, pud=08000000028e9003, pmd=0000000000000000 Internal error: Oops: 0000000096000006 [#1] SMP Modules linked in: netconsole dwc3_meson_g12a dwc3_of_simple dwc3 ip_gre gre ath10k_pci ath10k_core ath9k ath9k_common ath9k_hw ath CPU: 0 PID: 1091 Comm: kworker/u8:0 Not tainted 6.4.0-02144-g565f9a3a7911-dirty #705 Hardware name: RPT (r1) (DT) Workqueue: bat_events batadv_v_elp_throughput_metric_update pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : ath10k_sta_statistics+0x10/0x2dc [ath10k_core] lr : sta_set_sinfo+0xcc/0xbd4 sp : ffff000007b43ad0 x29: ffff000007b43ad0 x28: ffff0000071fa900 x27: ffff00000294ca98 x26: ffff000006830880 x25: ffff000006830880 x24: ffff00000294c000 x23: 0000000000000001 x22: ffff000007b43c90 x21: ffff800008898acc x20: ffff00000294c6e8 x19: ffff000007b43c90 x18: 0000000000000000 x17: 445946354d552d78 x16: 62661f7200000000 x15: 57464f445946354d x14: 0000000000000000 x13: 00000000000000e3 x12: d5f0acbcebea978e x11: 00000000000000e3 x10: 000000010048fe41 x9 : 0000000000000000 x8 : ffff000007b43d90 x7 : 000000007a1e2125 x6 : 0000000000000000 x5 : ffff0000024e0900 x4 : ffff800000a0250c x3 : ffff000007b43c90 x2 : ffff00000294ca98 x1 : ffff000006831920 x0 : 0000000000000000 Call trace: ath10k_sta_statistics+0x10/0x2dc [ath10k_core] sta_set_sinfo+0xcc/0xbd4 ieee80211_get_station+0x2c/0x44 cfg80211_get_station+0x80/0x154 batadv_v_elp_get_throughput+0x138/0x1fc batadv_v_elp_throughput_metric_update+0x1c/0xa4 process_one_work+0x1ec/0x414 worker_thread+0x70/0x46c kthread+0xdc/0xe0 ret_from_fork+0x10/0x20 Code: a9bb7bfd 910003fd a90153f3 f9411c40 (f9402814) This happens because STA has time to disconnect and reconnect before batadv_v_elp_throughput_metric_update() delayed work gets scheduled. In this situation, ath10k_sta_state() can be in the middle of resetting arsta data when the work queue get chance to be scheduled and ends up accessing it. Locking wiphy prevents that.
An issue was discovered in the Linux kernel before 5.11.11. The netfilter subsystem allows attackers to cause a denial of service (panic) because net/netfilter/x_tables.c and include/linux/netfilter/x_tables.h lack a full memory barrier upon the assignment of a new table value, aka CID-175e476b8cdf.
In the Linux kernel, the following vulnerability has been resolved: drm/dp: Fix divide-by-zero regression on DP MST unplug with nouveau Fix a regression when using nouveau and unplugging a StarTech MSTDP122DP DisplayPort 1.2 MST hub (the same regression does not appear when using a Cable Matters DisplayPort 1.4 MST hub). Trace: divide error: 0000 [#1] PREEMPT SMP PTI CPU: 7 PID: 2962 Comm: Xorg Not tainted 6.8.0-rc3+ #744 Hardware name: Razer Blade/DANA_MB, BIOS 01.01 08/31/2018 RIP: 0010:drm_dp_bw_overhead+0xb4/0x110 [drm_display_helper] Code: c6 b8 01 00 00 00 75 61 01 c6 41 0f af f3 41 0f af f1 c1 e1 04 48 63 c7 31 d2 89 ff 48 8b 5d f8 c9 48 0f af f1 48 8d 44 06 ff <48> f7 f7 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 45 31 RSP: 0018:ffffb2c5c211fa30 EFLAGS: 00010206 RAX: ffffffffffffffff RBX: 0000000000000000 RCX: 0000000000f59b00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffb2c5c211fa48 R08: 0000000000000001 R09: 0000000000000020 R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000023b4a R13: ffff91d37d165800 R14: ffff91d36fac6d80 R15: ffff91d34a764010 FS: 00007f4a1ca3fa80(0000) GS:ffff91d6edbc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559491d49000 CR3: 000000011d180002 CR4: 00000000003706f0 Call Trace: <TASK> ? show_regs+0x6d/0x80 ? die+0x37/0xa0 ? do_trap+0xd4/0xf0 ? do_error_trap+0x71/0xb0 ? drm_dp_bw_overhead+0xb4/0x110 [drm_display_helper] ? exc_divide_error+0x3a/0x70 ? drm_dp_bw_overhead+0xb4/0x110 [drm_display_helper] ? asm_exc_divide_error+0x1b/0x20 ? drm_dp_bw_overhead+0xb4/0x110 [drm_display_helper] ? drm_dp_calc_pbn_mode+0x2e/0x70 [drm_display_helper] nv50_msto_atomic_check+0xda/0x120 [nouveau] drm_atomic_helper_check_modeset+0xa87/0xdf0 [drm_kms_helper] drm_atomic_helper_check+0x19/0xa0 [drm_kms_helper] nv50_disp_atomic_check+0x13f/0x2f0 [nouveau] drm_atomic_check_only+0x668/0xb20 [drm] ? drm_connector_list_iter_next+0x86/0xc0 [drm] drm_atomic_commit+0x58/0xd0 [drm] ? __pfx___drm_printfn_info+0x10/0x10 [drm] drm_atomic_connector_commit_dpms+0xd7/0x100 [drm] drm_mode_obj_set_property_ioctl+0x1c5/0x450 [drm] ? __pfx_drm_connector_property_set_ioctl+0x10/0x10 [drm] drm_connector_property_set_ioctl+0x3b/0x60 [drm] drm_ioctl_kernel+0xb9/0x120 [drm] drm_ioctl+0x2d0/0x550 [drm] ? __pfx_drm_connector_property_set_ioctl+0x10/0x10 [drm] nouveau_drm_ioctl+0x61/0xc0 [nouveau] __x64_sys_ioctl+0xa0/0xf0 do_syscall_64+0x76/0x140 ? do_syscall_64+0x85/0x140 ? do_syscall_64+0x85/0x140 entry_SYSCALL_64_after_hwframe+0x6e/0x76 RIP: 0033:0x7f4a1cd1a94f Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 77 1f 48 8b 44 24 18 64 48 2b 04 25 28 00 RSP: 002b:00007ffd2f1df520 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffd2f1df5b0 RCX: 00007f4a1cd1a94f RDX: 00007ffd2f1df5b0 RSI: 00000000c01064ab RDI: 000000000000000f RBP: 00000000c01064ab R08: 000056347932deb8 R09: 000056347a7d99c0 R10: 0000000000000000 R11: 0000000000000246 R12: 000056347938a220 R13: 000000000000000f R14: 0000563479d9f3f0 R15: 0000000000000000 </TASK> Modules linked in: rfcomm xt_conntrack nft_chain_nat xt_MASQUERADE nf_nat nf_conntrack_netlink nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xfrm_user xfrm_algo xt_addrtype nft_compat nf_tables nfnetlink br_netfilter bridge stp llc ccm cmac algif_hash overlay algif_skcipher af_alg bnep binfmt_misc snd_sof_pci_intel_cnl snd_sof_intel_hda_common snd_soc_hdac_hda snd_sof_pci snd_sof_xtensa_dsp snd_sof_intel_hda snd_sof snd_sof_utils snd_soc_acpi_intel_match snd_soc_acpi snd_soc_core snd_compress snd_sof_intel_hda_mlink snd_hda_ext_core iwlmvm intel_rapl_msr intel_rapl_common intel_tcc_cooling x86_pkg_temp_thermal intel_powerclamp mac80211 coretemp kvm_intel snd_hda_codec_hdmi kvm snd_hda_ ---truncated---
In the Linux kernel, the following vulnerability has been resolved: dpll: fix possible deadlock during netlink dump operation Recently, I've been hitting following deadlock warning during dpll pin dump: [52804.637962] ====================================================== [52804.638536] WARNING: possible circular locking dependency detected [52804.639111] 6.8.0-rc2jiri+ #1 Not tainted [52804.639529] ------------------------------------------------------ [52804.640104] python3/2984 is trying to acquire lock: [52804.640581] ffff88810e642678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: netlink_dump+0xb3/0x780 [52804.641417] but task is already holding lock: [52804.642010] ffffffff83bde4c8 (dpll_lock){+.+.}-{3:3}, at: dpll_lock_dumpit+0x13/0x20 [52804.642747] which lock already depends on the new lock. [52804.643551] the existing dependency chain (in reverse order) is: [52804.644259] -> #1 (dpll_lock){+.+.}-{3:3}: [52804.644836] lock_acquire+0x174/0x3e0 [52804.645271] __mutex_lock+0x119/0x1150 [52804.645723] dpll_lock_dumpit+0x13/0x20 [52804.646169] genl_start+0x266/0x320 [52804.646578] __netlink_dump_start+0x321/0x450 [52804.647056] genl_family_rcv_msg_dumpit+0x155/0x1e0 [52804.647575] genl_rcv_msg+0x1ed/0x3b0 [52804.648001] netlink_rcv_skb+0xdc/0x210 [52804.648440] genl_rcv+0x24/0x40 [52804.648831] netlink_unicast+0x2f1/0x490 [52804.649290] netlink_sendmsg+0x36d/0x660 [52804.649742] __sock_sendmsg+0x73/0xc0 [52804.650165] __sys_sendto+0x184/0x210 [52804.650597] __x64_sys_sendto+0x72/0x80 [52804.651045] do_syscall_64+0x6f/0x140 [52804.651474] entry_SYSCALL_64_after_hwframe+0x46/0x4e [52804.652001] -> #0 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}: [52804.652650] check_prev_add+0x1ae/0x1280 [52804.653107] __lock_acquire+0x1ed3/0x29a0 [52804.653559] lock_acquire+0x174/0x3e0 [52804.653984] __mutex_lock+0x119/0x1150 [52804.654423] netlink_dump+0xb3/0x780 [52804.654845] __netlink_dump_start+0x389/0x450 [52804.655321] genl_family_rcv_msg_dumpit+0x155/0x1e0 [52804.655842] genl_rcv_msg+0x1ed/0x3b0 [52804.656272] netlink_rcv_skb+0xdc/0x210 [52804.656721] genl_rcv+0x24/0x40 [52804.657119] netlink_unicast+0x2f1/0x490 [52804.657570] netlink_sendmsg+0x36d/0x660 [52804.658022] __sock_sendmsg+0x73/0xc0 [52804.658450] __sys_sendto+0x184/0x210 [52804.658877] __x64_sys_sendto+0x72/0x80 [52804.659322] do_syscall_64+0x6f/0x140 [52804.659752] entry_SYSCALL_64_after_hwframe+0x46/0x4e [52804.660281] other info that might help us debug this: [52804.661077] Possible unsafe locking scenario: [52804.661671] CPU0 CPU1 [52804.662129] ---- ---- [52804.662577] lock(dpll_lock); [52804.662924] lock(nlk_cb_mutex-GENERIC); [52804.663538] lock(dpll_lock); [52804.664073] lock(nlk_cb_mutex-GENERIC); [52804.664490] The issue as follows: __netlink_dump_start() calls control->start(cb) with nlk->cb_mutex held. In control->start(cb) the dpll_lock is taken. Then nlk->cb_mutex is released and taken again in netlink_dump(), while dpll_lock still being held. That leads to ABBA deadlock when another CPU races with the same operation. Fix this by moving dpll_lock taking into dumpit() callback which ensures correct lock taking order.
In the Linux kernel, the following vulnerability has been resolved: xsk: fix usage of multi-buffer BPF helpers for ZC XDP Currently when packet is shrunk via bpf_xdp_adjust_tail() and memory type is set to MEM_TYPE_XSK_BUFF_POOL, null ptr dereference happens: [1136314.192256] BUG: kernel NULL pointer dereference, address: 0000000000000034 [1136314.203943] #PF: supervisor read access in kernel mode [1136314.213768] #PF: error_code(0x0000) - not-present page [1136314.223550] PGD 0 P4D 0 [1136314.230684] Oops: 0000 [#1] PREEMPT SMP NOPTI [1136314.239621] CPU: 8 PID: 54203 Comm: xdpsock Not tainted 6.6.0+ #257 [1136314.250469] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [1136314.265615] RIP: 0010:__xdp_return+0x6c/0x210 [1136314.274653] Code: ad 00 48 8b 47 08 49 89 f8 a8 01 0f 85 9b 01 00 00 0f 1f 44 00 00 f0 41 ff 48 34 75 32 4c 89 c7 e9 79 cd 80 ff 83 fe 03 75 17 <f6> 41 34 01 0f 85 02 01 00 00 48 89 cf e9 22 cc 1e 00 e9 3d d2 86 [1136314.302907] RSP: 0018:ffffc900089f8db0 EFLAGS: 00010246 [1136314.312967] RAX: ffffc9003168aed0 RBX: ffff8881c3300000 RCX: 0000000000000000 [1136314.324953] RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffffc9003168c000 [1136314.336929] RBP: 0000000000000ae0 R08: 0000000000000002 R09: 0000000000010000 [1136314.348844] R10: ffffc9000e495000 R11: 0000000000000040 R12: 0000000000000001 [1136314.360706] R13: 0000000000000524 R14: ffffc9003168aec0 R15: 0000000000000001 [1136314.373298] FS: 00007f8df8bbcb80(0000) GS:ffff8897e0e00000(0000) knlGS:0000000000000000 [1136314.386105] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1136314.396532] CR2: 0000000000000034 CR3: 00000001aa912002 CR4: 00000000007706f0 [1136314.408377] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [1136314.420173] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [1136314.431890] PKRU: 55555554 [1136314.439143] Call Trace: [1136314.446058] <IRQ> [1136314.452465] ? __die+0x20/0x70 [1136314.459881] ? page_fault_oops+0x15b/0x440 [1136314.468305] ? exc_page_fault+0x6a/0x150 [1136314.476491] ? asm_exc_page_fault+0x22/0x30 [1136314.484927] ? __xdp_return+0x6c/0x210 [1136314.492863] bpf_xdp_adjust_tail+0x155/0x1d0 [1136314.501269] bpf_prog_ccc47ae29d3b6570_xdp_sock_prog+0x15/0x60 [1136314.511263] ice_clean_rx_irq_zc+0x206/0xc60 [ice] [1136314.520222] ? ice_xmit_zc+0x6e/0x150 [ice] [1136314.528506] ice_napi_poll+0x467/0x670 [ice] [1136314.536858] ? ttwu_do_activate.constprop.0+0x8f/0x1a0 [1136314.546010] __napi_poll+0x29/0x1b0 [1136314.553462] net_rx_action+0x133/0x270 [1136314.561619] __do_softirq+0xbe/0x28e [1136314.569303] do_softirq+0x3f/0x60 This comes from __xdp_return() call with xdp_buff argument passed as NULL which is supposed to be consumed by xsk_buff_free() call. To address this properly, in ZC case, a node that represents the frag being removed has to be pulled out of xskb_list. Introduce appropriate xsk helpers to do such node operation and use them accordingly within bpf_xdp_adjust_tail().
In the Linux kernel, the following vulnerability has been resolved: igc: avoid returning frame twice in XDP_REDIRECT When a frame can not be transmitted in XDP_REDIRECT (e.g. due to a full queue), it is necessary to free it by calling xdp_return_frame_rx_napi. However, this is the responsibility of the caller of the ndo_xdp_xmit (see for example bq_xmit_all in kernel/bpf/devmap.c) and thus calling it inside igc_xdp_xmit (which is the ndo_xdp_xmit of the igc driver) as well will lead to memory corruption. In fact, bq_xmit_all expects that it can return all frames after the last successfully transmitted one. Therefore, break for the first not transmitted frame, but do not call xdp_return_frame_rx_napi in igc_xdp_xmit. This is equally implemented in other Intel drivers such as the igb. There are two alternatives to this that were rejected: 1. Return num_frames as all the frames would have been transmitted and release them inside igc_xdp_xmit. While it might work technically, it is not what the return value is meant to represent (i.e. the number of SUCCESSFULLY transmitted packets). 2. Rework kernel/bpf/devmap.c and all drivers to support non-consecutively dropped packets. Besides being complex, it likely has a negative performance impact without a significant gain since it is anyway unlikely that the next frame can be transmitted if the previous one was dropped. The memory corruption can be reproduced with the following script which leads to a kernel panic after a few seconds. It basically generates more traffic than a i225 NIC can transmit and pushes it via XDP_REDIRECT from a virtual interface to the physical interface where frames get dropped. #!/bin/bash INTERFACE=enp4s0 INTERFACE_IDX=`cat /sys/class/net/$INTERFACE/ifindex` sudo ip link add dev veth1 type veth peer name veth2 sudo ip link set up $INTERFACE sudo ip link set up veth1 sudo ip link set up veth2 cat << EOF > redirect.bpf.c SEC("prog") int redirect(struct xdp_md *ctx) { return bpf_redirect($INTERFACE_IDX, 0); } char _license[] SEC("license") = "GPL"; EOF clang -O2 -g -Wall -target bpf -c redirect.bpf.c -o redirect.bpf.o sudo ip link set veth2 xdp obj redirect.bpf.o cat << EOF > pass.bpf.c SEC("prog") int pass(struct xdp_md *ctx) { return XDP_PASS; } char _license[] SEC("license") = "GPL"; EOF clang -O2 -g -Wall -target bpf -c pass.bpf.c -o pass.bpf.o sudo ip link set $INTERFACE xdp obj pass.bpf.o cat << EOF > trafgen.cfg { /* Ethernet Header */ 0xe8, 0x6a, 0x64, 0x41, 0xbf, 0x46, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, const16(ETH_P_IP), /* IPv4 Header */ 0b01000101, 0, # IPv4 version, IHL, TOS const16(1028), # IPv4 total length (UDP length + 20 bytes (IP header)) const16(2), # IPv4 ident 0b01000000, 0, # IPv4 flags, fragmentation off 64, # IPv4 TTL 17, # Protocol UDP csumip(14, 33), # IPv4 checksum /* UDP Header */ 10, 0, 1, 1, # IP Src - adapt as needed 10, 0, 1, 2, # IP Dest - adapt as needed const16(6666), # UDP Src Port const16(6666), # UDP Dest Port const16(1008), # UDP length (UDP header 8 bytes + payload length) csumudp(14, 34), # UDP checksum /* Payload */ fill('W', 1000), } EOF sudo trafgen -i trafgen.cfg -b3000MB -o veth1 --cpp
In the Linux kernel, the following vulnerability has been resolved: geneve: make sure to pull inner header in geneve_rx() syzbot triggered a bug in geneve_rx() [1] Issue is similar to the one I fixed in commit 8d975c15c0cd ("ip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv()") We have to save skb->network_header in a temporary variable in order to be able to recompute the network_header pointer after a pskb_inet_may_pull() call. pskb_inet_may_pull() makes sure the needed headers are in skb->head. [1] BUG: KMSAN: uninit-value in IP_ECN_decapsulate include/net/inet_ecn.h:302 [inline] BUG: KMSAN: uninit-value in geneve_rx drivers/net/geneve.c:279 [inline] BUG: KMSAN: uninit-value in geneve_udp_encap_recv+0x36f9/0x3c10 drivers/net/geneve.c:391 IP_ECN_decapsulate include/net/inet_ecn.h:302 [inline] geneve_rx drivers/net/geneve.c:279 [inline] geneve_udp_encap_recv+0x36f9/0x3c10 drivers/net/geneve.c:391 udp_queue_rcv_one_skb+0x1d39/0x1f20 net/ipv4/udp.c:2108 udp_queue_rcv_skb+0x6ae/0x6e0 net/ipv4/udp.c:2186 udp_unicast_rcv_skb+0x184/0x4b0 net/ipv4/udp.c:2346 __udp4_lib_rcv+0x1c6b/0x3010 net/ipv4/udp.c:2422 udp_rcv+0x7d/0xa0 net/ipv4/udp.c:2604 ip_protocol_deliver_rcu+0x264/0x1300 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2b8/0x440 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:461 [inline] ip_rcv_finish net/ipv4/ip_input.c:449 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] ip_rcv+0x46f/0x760 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core net/core/dev.c:5534 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5648 process_backlog+0x480/0x8b0 net/core/dev.c:5976 __napi_poll+0xe3/0x980 net/core/dev.c:6576 napi_poll net/core/dev.c:6645 [inline] net_rx_action+0x8b8/0x1870 net/core/dev.c:6778 __do_softirq+0x1b7/0x7c5 kernel/softirq.c:553 do_softirq+0x9a/0xf0 kernel/softirq.c:454 __local_bh_enable_ip+0x9b/0xa0 kernel/softirq.c:381 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:820 [inline] __dev_queue_xmit+0x2768/0x51c0 net/core/dev.c:4378 dev_queue_xmit include/linux/netdevice.h:3171 [inline] packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3081 [inline] packet_sendmsg+0x8aef/0x9f10 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x735/0xa10 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: slab_post_alloc_hook mm/slub.c:3819 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc_node+0x5cb/0xbc0 mm/slub.c:3903 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560 __alloc_skb+0x352/0x790 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1296 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6394 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2783 packet_alloc_skb net/packet/af_packet.c:2930 [inline] packet_snd net/packet/af_packet.c:3024 [inline] packet_sendmsg+0x70c2/0x9f10 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x735/0xa10 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b
In the Linux kernel, the following vulnerability has been resolved: NFS: Fix nfs_netfs_issue_read() xarray locking for writeback interrupt The loop inside nfs_netfs_issue_read() currently does not disable interrupts while iterating through pages in the xarray to submit for NFS read. This is not safe though since after taking xa_lock, another page in the mapping could be processed for writeback inside an interrupt, and deadlock can occur. The fix is simple and clean if we use xa_for_each_range(), which handles the iteration with RCU while reducing code complexity. The problem is easily reproduced with the following test: mount -o vers=3,fsc 127.0.0.1:/export /mnt/nfs dd if=/dev/zero of=/mnt/nfs/file1.bin bs=4096 count=1 echo 3 > /proc/sys/vm/drop_caches dd if=/mnt/nfs/file1.bin of=/dev/null umount /mnt/nfs On the console with a lockdep-enabled kernel a message similar to the following will be seen: ================================ WARNING: inconsistent lock state 6.7.0-lockdbg+ #10 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. test5/1708 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff888127baa598 (&xa->xa_lock#4){+.?.}-{3:3}, at: nfs_netfs_issue_read+0x1b2/0x4b0 [nfs] {IN-SOFTIRQ-W} state was registered at: lock_acquire+0x144/0x380 _raw_spin_lock_irqsave+0x4e/0xa0 __folio_end_writeback+0x17e/0x5c0 folio_end_writeback+0x93/0x1b0 iomap_finish_ioend+0xeb/0x6a0 blk_update_request+0x204/0x7f0 blk_mq_end_request+0x30/0x1c0 blk_complete_reqs+0x7e/0xa0 __do_softirq+0x113/0x544 __irq_exit_rcu+0xfe/0x120 irq_exit_rcu+0xe/0x20 sysvec_call_function_single+0x6f/0x90 asm_sysvec_call_function_single+0x1a/0x20 pv_native_safe_halt+0xf/0x20 default_idle+0x9/0x20 default_idle_call+0x67/0xa0 do_idle+0x2b5/0x300 cpu_startup_entry+0x34/0x40 start_secondary+0x19d/0x1c0 secondary_startup_64_no_verify+0x18f/0x19b irq event stamp: 176891 hardirqs last enabled at (176891): [<ffffffffa67a0be4>] _raw_spin_unlock_irqrestore+0x44/0x60 hardirqs last disabled at (176890): [<ffffffffa67a0899>] _raw_spin_lock_irqsave+0x79/0xa0 softirqs last enabled at (176646): [<ffffffffa515d91e>] __irq_exit_rcu+0xfe/0x120 softirqs last disabled at (176633): [<ffffffffa515d91e>] __irq_exit_rcu+0xfe/0x120 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&xa->xa_lock#4); <Interrupt> lock(&xa->xa_lock#4); *** DEADLOCK *** 2 locks held by test5/1708: #0: ffff888127baa498 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: nfs_start_io_read+0x28/0x90 [nfs] #1: ffff888127baa650 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: page_cache_ra_unbounded+0xa4/0x280 stack backtrace: CPU: 6 PID: 1708 Comm: test5 Kdump: loaded Not tainted 6.7.0-lockdbg+ Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014 Call Trace: dump_stack_lvl+0x5b/0x90 mark_lock+0xb3f/0xd20 __lock_acquire+0x77b/0x3360 _raw_spin_lock+0x34/0x80 nfs_netfs_issue_read+0x1b2/0x4b0 [nfs] netfs_begin_read+0x77f/0x980 [netfs] nfs_netfs_readahead+0x45/0x60 [nfs] nfs_readahead+0x323/0x5a0 [nfs] read_pages+0xf3/0x5c0 page_cache_ra_unbounded+0x1c8/0x280 filemap_get_pages+0x38c/0xae0 filemap_read+0x206/0x5e0 nfs_file_read+0xb7/0x140 [nfs] vfs_read+0x2a9/0x460 ksys_read+0xb7/0x140
In intel_pmu_drain_pebs_nhm in arch/x86/events/intel/ds.c in the Linux kernel through 5.11.8 on some Haswell CPUs, userspace applications (such as perf-fuzzer) can cause a system crash because the PEBS status in a PEBS record is mishandled, aka CID-d88d05a9e0b6.
In the Linux kernel, the following vulnerability has been resolved: memcg: fix soft lockup in the OOM process A soft lockup issue was found in the product with about 56,000 tasks were in the OOM cgroup, it was traversing them when the soft lockup was triggered. watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [VM Thread:1503066] CPU: 2 PID: 1503066 Comm: VM Thread Kdump: loaded Tainted: G Hardware name: Huawei Cloud OpenStack Nova, BIOS RIP: 0010:console_unlock+0x343/0x540 RSP: 0000:ffffb751447db9a0 EFLAGS: 00000247 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000ffffffff RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000247 RBP: ffffffffafc71f90 R08: 0000000000000000 R09: 0000000000000040 R10: 0000000000000080 R11: 0000000000000000 R12: ffffffffafc74bd0 R13: ffffffffaf60a220 R14: 0000000000000247 R15: 0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2fe6ad91f0 CR3: 00000004b2076003 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vprintk_emit+0x193/0x280 printk+0x52/0x6e dump_task+0x114/0x130 mem_cgroup_scan_tasks+0x76/0x100 dump_header+0x1fe/0x210 oom_kill_process+0xd1/0x100 out_of_memory+0x125/0x570 mem_cgroup_out_of_memory+0xb5/0xd0 try_charge+0x720/0x770 mem_cgroup_try_charge+0x86/0x180 mem_cgroup_try_charge_delay+0x1c/0x40 do_anonymous_page+0xb5/0x390 handle_mm_fault+0xc4/0x1f0 This is because thousands of processes are in the OOM cgroup, it takes a long time to traverse all of them. As a result, this lead to soft lockup in the OOM process. To fix this issue, call 'cond_resched' in the 'mem_cgroup_scan_tasks' function per 1000 iterations. For global OOM, call 'touch_softlockup_watchdog' per 1000 iterations to avoid this issue.
In the Linux kernel, the following vulnerability has been resolved: xhci: handle isoc Babble and Buffer Overrun events properly xHCI 4.9 explicitly forbids assuming that the xHC has released its ownership of a multi-TRB TD when it reports an error on one of the early TRBs. Yet the driver makes such assumption and releases the TD, allowing the remaining TRBs to be freed or overwritten by new TDs. The xHC should also report completion of the final TRB due to its IOC flag being set by us, regardless of prior errors. This event cannot be recognized if the TD has already been freed earlier, resulting in "Transfer event TRB DMA ptr not part of current TD" error message. Fix this by reusing the logic for processing isoc Transaction Errors. This also handles hosts which fail to report the final completion. Fix transfer length reporting on Babble errors. They may be caused by device malfunction, no guarantee that the buffer has been filled.
In the Linux kernel, the following vulnerability has been resolved: speakup: Avoid crash on very long word In case a console is set up really large and contains a really long word (> 256 characters), we have to stop before the length of the word buffer.
An issue was discovered in the Linux kernel through 5.11.11. synic_get in arch/x86/kvm/hyperv.c has a NULL pointer dereference for certain accesses to the SynIC Hyper-V context, aka CID-919f4ebc5987.
In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix memory leak in dm_sw_fini() After destroying dmub_srv, the memory associated with it is not freed, causing a memory leak: unreferenced object 0xffff896302b45800 (size 1024): comm "(udev-worker)", pid 222, jiffies 4294894636 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc 6265fd77): [<ffffffff993495ed>] kmalloc_trace+0x29d/0x340 [<ffffffffc0ea4a94>] dm_dmub_sw_init+0xb4/0x450 [amdgpu] [<ffffffffc0ea4e55>] dm_sw_init+0x15/0x2b0 [amdgpu] [<ffffffffc0ba8557>] amdgpu_device_init+0x1417/0x24e0 [amdgpu] [<ffffffffc0bab285>] amdgpu_driver_load_kms+0x15/0x190 [amdgpu] [<ffffffffc0ba09c7>] amdgpu_pci_probe+0x187/0x4e0 [amdgpu] [<ffffffff9968fd1e>] local_pci_probe+0x3e/0x90 [<ffffffff996918a3>] pci_device_probe+0xc3/0x230 [<ffffffff99805872>] really_probe+0xe2/0x480 [<ffffffff99805c98>] __driver_probe_device+0x78/0x160 [<ffffffff99805daf>] driver_probe_device+0x1f/0x90 [<ffffffff9980601e>] __driver_attach+0xce/0x1c0 [<ffffffff99803170>] bus_for_each_dev+0x70/0xc0 [<ffffffff99804822>] bus_add_driver+0x112/0x210 [<ffffffff99807245>] driver_register+0x55/0x100 [<ffffffff990012d1>] do_one_initcall+0x41/0x300 Fix this by freeing dmub_srv after destroying it.
In the Linux kernel, the following vulnerability has been resolved: netfs/fscache: Add a memory barrier for FSCACHE_VOLUME_CREATING In fscache_create_volume(), there is a missing memory barrier between the bit-clearing operation and the wake-up operation. This may cause a situation where, after a wake-up, the bit-clearing operation hasn't been detected yet, leading to an indefinite wait. The triggering process is as follows: [cookie1] [cookie2] [volume_work] fscache_perform_lookup fscache_create_volume fscache_perform_lookup fscache_create_volume fscache_create_volume_work cachefiles_acquire_volume clear_and_wake_up_bit test_and_set_bit test_and_set_bit goto maybe_wait goto no_wait In the above process, cookie1 and cookie2 has the same volume. When cookie1 enters the -no_wait- process, it will clear the bit and wake up the waiting process. If a barrier is missing, it may cause cookie2 to remain in the -wait- process indefinitely. In commit 3288666c7256 ("fscache: Use clear_and_wake_up_bit() in fscache_create_volume_work()"), barriers were added to similar operations in fscache_create_volume_work(), but fscache_create_volume() was missed. By combining the clear and wake operations into clear_and_wake_up_bit() to fix this issue.
In the Linux kernel, the following vulnerability has been resolved: arm64: entry: fix ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD Currently the ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD workaround isn't quite right, as it is supposed to be applied after the last explicit memory access, but is immediately followed by an LDR. The ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD workaround is used to handle Cortex-A520 erratum 2966298 and Cortex-A510 erratum 3117295, which are described in: * https://developer.arm.com/documentation/SDEN2444153/0600/?lang=en * https://developer.arm.com/documentation/SDEN1873361/1600/?lang=en In both cases the workaround is described as: | If pagetable isolation is disabled, the context switch logic in the | kernel can be updated to execute the following sequence on affected | cores before exiting to EL0, and after all explicit memory accesses: | | 1. A non-shareable TLBI to any context and/or address, including | unused contexts or addresses, such as a `TLBI VALE1 Xzr`. | | 2. A DSB NSH to guarantee completion of the TLBI. The important part being that the TLBI+DSB must be placed "after all explicit memory accesses". Unfortunately, as-implemented, the TLBI+DSB is immediately followed by an LDR, as we have: | alternative_if ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD | tlbi vale1, xzr | dsb nsh | alternative_else_nop_endif | alternative_if_not ARM64_UNMAP_KERNEL_AT_EL0 | ldr lr, [sp, #S_LR] | add sp, sp, #PT_REGS_SIZE // restore sp | eret | alternative_else_nop_endif | | [ ... KPTI exception return path ... ] This patch fixes this by reworking the logic to place the TLBI+DSB immediately before the ERET, after all explicit memory accesses. The ERET is currently in a separate alternative block, and alternatives cannot be nested. To account for this, the alternative block for ARM64_UNMAP_KERNEL_AT_EL0 is replaced with a single alternative branch to skip the KPTI logic, with the new shape of the logic being: | alternative_insn "b .L_skip_tramp_exit_\@", nop, ARM64_UNMAP_KERNEL_AT_EL0 | [ ... KPTI exception return path ... ] | .L_skip_tramp_exit_\@: | | ldr lr, [sp, #S_LR] | add sp, sp, #PT_REGS_SIZE // restore sp | | alternative_if ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD | tlbi vale1, xzr | dsb nsh | alternative_else_nop_endif | eret The new structure means that the workaround is only applied when KPTI is not in use; this is fine as noted in the documented implications of the erratum: | Pagetable isolation between EL0 and higher level ELs prevents the | issue from occurring. ... and as per the workaround description quoted above, the workaround is only necessary "If pagetable isolation is disabled".