In the Linux kernel, the following vulnerability has been resolved: net: fujitsu: fix potential null-ptr-deref In fmvj18x_get_hwinfo(), if ioremap fails there will be NULL pointer deref. To fix this, check the return value of ioremap and return -1 to the caller in case of failure.

In the Linux kernel, the following vulnerability has been resolved: sctp: break out if skb_header_pointer returns NULL in sctp_rcv_ootb We should always check if skb_header_pointer's return is NULL before using it, otherwise it may cause null-ptr-deref, as syzbot reported: KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:sctp_rcv_ootb net/sctp/input.c:705 [inline] RIP: 0010:sctp_rcv+0x1d84/0x3220 net/sctp/input.c:196 Call Trace: <IRQ> sctp6_rcv+0x38/0x60 net/sctp/ipv6.c:1109 ip6_protocol_deliver_rcu+0x2e9/0x1ca0 net/ipv6/ip6_input.c:422 ip6_input_finish+0x62/0x170 net/ipv6/ip6_input.c:463 NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:472 dst_input include/net/dst.h:460 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297

In the Linux kernel, the following vulnerability has been resolved: usb: misc: brcmstb-usb-pinmap: check return value after calling platform_get_resource() It will cause null-ptr-deref if platform_get_resource() returns NULL, we need check the return value.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: Update intermediate power state for SI Update the current state as boot state during dpm initialization. During the subsequent initialization, set_power_state gets called to transition to the final power state. set_power_state refers to values from the current state and without current state populated, it could result in NULL pointer dereference. For ex: on platforms where PCI speed change is supported through ACPI ATCS method, the link speed of current state needs to be queried before deciding on changing to final power state's link speed. The logic to query ATCS-support was broken on certain platforms. The issue became visible when broken ATCS-support logic got fixed with commit f9b7f3703ff9 ("drm/amdgpu/acpi: make ATPX/ATCS structures global (v2)"). Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1698

In the Linux kernel, the following vulnerability has been resolved: memory: renesas-rpc-if: fix possible NULL pointer dereference of resource The platform_get_resource_byname() can return NULL which would be immediately dereferenced by resource_size(). Instead dereference it after validating the resource. Addresses-Coverity: Dereference null return value

In the Linux kernel, the following vulnerability has been resolved: scsi: lpfc: Fix null pointer dereference in lpfc_prep_els_iocb() It is possible to call lpfc_issue_els_plogi() passing a did for which no matching ndlp is found. A call is then made to lpfc_prep_els_iocb() with a null pointer to a lpfc_nodelist structure resulting in a null pointer dereference. Fix by returning an error status if no valid ndlp is found. Fix up comments regarding ndlp reference counting.

In the Linux kernel, the following vulnerability has been resolved: drm/virtio: Ensure that objs is not NULL in virtio_gpu_array_put_free() If virtio_gpu_object_shmem_init() fails (e.g. due to fault injection, as it happened in the bug report by syzbot), virtio_gpu_array_put_free() could be called with objs equal to NULL. Ensure that objs is not NULL in virtio_gpu_array_put_free(), or otherwise return from the function.

In the Linux kernel, the following vulnerability has been resolved: ALSA: gus: fix null pointer dereference on pointer block The pointer block return from snd_gf1_dma_next_block could be null, so there is a potential null pointer dereference issue. Fix this by adding a null check before dereference.

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Clear ffs_eventfd in ffs_data_clear. ffs_data_clear is indirectly called from both ffs_fs_kill_sb and ffs_ep0_release, so it ends up being called twice when userland closes ep0 and then unmounts f_fs. If userland provided an eventfd along with function's USB descriptors, it ends up calling eventfd_ctx_put as many times, causing a refcount underflow. NULL-ify ffs_eventfd to prevent these extraneous eventfd_ctx_put calls. Also, set epfiles to NULL right after de-allocating it, for readability. For completeness, ffs_data_clear actually ends up being called thrice, the last call being before the whole ffs structure gets freed, so when this specific sequence happens there is a second underflow happening (but not being reported): /sys/kernel/debug/tracing# modprobe usb_f_fs /sys/kernel/debug/tracing# echo ffs_data_clear > set_ftrace_filter /sys/kernel/debug/tracing# echo function > current_tracer /sys/kernel/debug/tracing# echo 1 > tracing_on (setup gadget, run and kill function userland process, teardown gadget) /sys/kernel/debug/tracing# echo 0 > tracing_on /sys/kernel/debug/tracing# cat trace smartcard-openp-436 [000] ..... 1946.208786: ffs_data_clear <-ffs_data_closed smartcard-openp-431 [000] ..... 1946.279147: ffs_data_clear <-ffs_data_closed smartcard-openp-431 [000] .n... 1946.905512: ffs_data_clear <-ffs_data_put Warning output corresponding to above trace: [ 1946.284139] WARNING: CPU: 0 PID: 431 at lib/refcount.c:28 refcount_warn_saturate+0x110/0x15c [ 1946.293094] refcount_t: underflow; use-after-free. [ 1946.298164] Modules linked in: usb_f_ncm(E) u_ether(E) usb_f_fs(E) hci_uart(E) btqca(E) btrtl(E) btbcm(E) btintel(E) bluetooth(E) nls_ascii(E) nls_cp437(E) vfat(E) fat(E) bcm2835_v4l2(CE) bcm2835_mmal_vchiq(CE) videobuf2_vmalloc(E) videobuf2_memops(E) sha512_generic(E) videobuf2_v4l2(E) sha512_arm(E) videobuf2_common(E) videodev(E) cpufreq_dt(E) snd_bcm2835(CE) brcmfmac(E) mc(E) vc4(E) ctr(E) brcmutil(E) snd_soc_core(E) snd_pcm_dmaengine(E) drbg(E) snd_pcm(E) snd_timer(E) snd(E) soundcore(E) drm_kms_helper(E) cec(E) ansi_cprng(E) rc_core(E) syscopyarea(E) raspberrypi_cpufreq(E) sysfillrect(E) sysimgblt(E) cfg80211(E) max17040_battery(OE) raspberrypi_hwmon(E) fb_sys_fops(E) regmap_i2c(E) ecdh_generic(E) rfkill(E) ecc(E) bcm2835_rng(E) rng_core(E) vchiq(CE) leds_gpio(E) libcomposite(E) fuse(E) configfs(E) ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc16(E) mbcache(E) jbd2(E) crc32c_generic(E) sdhci_iproc(E) sdhci_pltfm(E) sdhci(E) [ 1946.399633] CPU: 0 PID: 431 Comm: smartcard-openp Tainted: G C OE 5.15.0-1-rpi #1 Debian 5.15.3-1 [ 1946.417950] Hardware name: BCM2835 [ 1946.425442] Backtrace: [ 1946.432048] [<c08d60a0>] (dump_backtrace) from [<c08d62ec>] (show_stack+0x20/0x24) [ 1946.448226] r7:00000009 r6:0000001c r5:c04a948c r4:c0a64e2c [ 1946.458412] [<c08d62cc>] (show_stack) from [<c08d9ae0>] (dump_stack+0x28/0x30) [ 1946.470380] [<c08d9ab8>] (dump_stack) from [<c0123500>] (__warn+0xe8/0x154) [ 1946.482067] r5:c04a948c r4:c0a71dc8 [ 1946.490184] [<c0123418>] (__warn) from [<c08d6948>] (warn_slowpath_fmt+0xa0/0xe4) [ 1946.506758] r7:00000009 r6:0000001c r5:c0a71dc8 r4:c0a71e04 [ 1946.517070] [<c08d68ac>] (warn_slowpath_fmt) from [<c04a948c>] (refcount_warn_saturate+0x110/0x15c) [ 1946.535309] r8:c0100224 r7:c0dfcb84 r6:ffffffff r5:c3b84c00 r4:c24a17c0 [ 1946.546708] [<c04a937c>] (refcount_warn_saturate) from [<c0380134>] (eventfd_ctx_put+0x48/0x74) [ 1946.564476] [<c03800ec>] (eventfd_ctx_put) from [<bf5464e8>] (ffs_data_clear+0xd0/0x118 [usb_f_fs]) [ 1946.582664] r5:c3b84c00 r4:c2695b00 [ 1946.590668] [<bf546418>] (ffs_data_clear [usb_f_fs]) from [<bf547cc0>] (ffs_data_closed+0x9c/0x150 [usb_f_fs]) [ 1946.609608] r5:bf54d014 r4:c2695b00 [ 1946.617522] [<bf547c24>] (ffs_data_closed [usb_f_fs]) from [<bf547da0>] (ffs_fs_kill_sb+0x2c/0x30 [usb_f_fs]) [ 1946.636217] r7:c0dfcb ---truncated---

In the Linux kernel, the following vulnerability has been resolved: jfs: fix GPF in diFree Avoid passing inode with JFS_SBI(inode->i_sb)->ipimap == NULL to diFree()[1]. GFP will appear: struct inode *ipimap = JFS_SBI(ip->i_sb)->ipimap; struct inomap *imap = JFS_IP(ipimap)->i_imap; JFS_IP() will return invalid pointer when ipimap == NULL Call Trace: diFree+0x13d/0x2dc0 fs/jfs/jfs_imap.c:853 [1] jfs_evict_inode+0x2c9/0x370 fs/jfs/inode.c:154 evict+0x2ed/0x750 fs/inode.c:578 iput_final fs/inode.c:1654 [inline] iput.part.0+0x3fe/0x820 fs/inode.c:1680 iput+0x58/0x70 fs/inode.c:1670

In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_debug: Don't call kcalloc() if size arg is zero If the size arg to kcalloc() is zero, it returns ZERO_SIZE_PTR. Because of that, for a following NULL pointer check to work on the returned pointer, kcalloc() must not be called with the size arg equal to zero. Return early without error before the kcalloc() call if size arg is zero. BUG: KASAN: null-ptr-deref in memcpy include/linux/fortify-string.h:191 [inline] BUG: KASAN: null-ptr-deref in sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974 Write of size 4 at addr 0000000000000010 by task syz-executor.1/22789 CPU: 1 PID: 22789 Comm: syz-executor.1 Not tainted 5.15.0-syzk #1 Hardware name: Red Hat KVM, BIOS 1.13.0-2 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106 __kasan_report mm/kasan/report.c:446 [inline] kasan_report.cold.14+0x112/0x117 mm/kasan/report.c:459 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x1a3/0x210 mm/kasan/generic.c:189 memcpy+0x3b/0x60 mm/kasan/shadow.c:66 memcpy include/linux/fortify-string.h:191 [inline] sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974 do_dout_fetch drivers/scsi/scsi_debug.c:2954 [inline] do_dout_fetch drivers/scsi/scsi_debug.c:2946 [inline] resp_verify+0x49e/0x930 drivers/scsi/scsi_debug.c:4276 schedule_resp+0x4d8/0x1a70 drivers/scsi/scsi_debug.c:5478 scsi_debug_queuecommand+0x8c9/0x1ec0 drivers/scsi/scsi_debug.c:7533 scsi_dispatch_cmd drivers/scsi/scsi_lib.c:1520 [inline] scsi_queue_rq+0x16b0/0x2d40 drivers/scsi/scsi_lib.c:1699 blk_mq_dispatch_rq_list+0xb9b/0x2700 block/blk-mq.c:1639 __blk_mq_sched_dispatch_requests+0x28f/0x590 block/blk-mq-sched.c:325 blk_mq_sched_dispatch_requests+0x105/0x190 block/blk-mq-sched.c:358 __blk_mq_run_hw_queue+0xe5/0x150 block/blk-mq.c:1761 __blk_mq_delay_run_hw_queue+0x4f8/0x5c0 block/blk-mq.c:1838 blk_mq_run_hw_queue+0x18d/0x350 block/blk-mq.c:1891 blk_mq_sched_insert_request+0x3db/0x4e0 block/blk-mq-sched.c:474 blk_execute_rq_nowait+0x16b/0x1c0 block/blk-exec.c:62 blk_execute_rq+0xdb/0x360 block/blk-exec.c:102 sg_scsi_ioctl drivers/scsi/scsi_ioctl.c:621 [inline] scsi_ioctl+0x8bb/0x15c0 drivers/scsi/scsi_ioctl.c:930 sg_ioctl_common+0x172d/0x2710 drivers/scsi/sg.c:1112 sg_ioctl+0xa2/0x180 drivers/scsi/sg.c:1165 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae

In the Linux kernel, the following vulnerability has been resolved: ocfs2: remove entry once instead of null-ptr-dereference in ocfs2_xa_remove() Syzkaller is able to provoke null-ptr-dereference in ocfs2_xa_remove(): [ 57.319872] (a.out,1161,7):ocfs2_xa_remove:2028 ERROR: status = -12 [ 57.320420] (a.out,1161,7):ocfs2_xa_cleanup_value_truncate:1999 ERROR: Partial truncate while removing xattr overlay.upper. Leaking 1 clusters and removing the entry [ 57.321727] BUG: kernel NULL pointer dereference, address: 0000000000000004 [...] [ 57.325727] RIP: 0010:ocfs2_xa_block_wipe_namevalue+0x2a/0xc0 [...] [ 57.331328] Call Trace: [ 57.331477] <TASK> [...] [ 57.333511] ? do_user_addr_fault+0x3e5/0x740 [ 57.333778] ? exc_page_fault+0x70/0x170 [ 57.334016] ? asm_exc_page_fault+0x2b/0x30 [ 57.334263] ? __pfx_ocfs2_xa_block_wipe_namevalue+0x10/0x10 [ 57.334596] ? ocfs2_xa_block_wipe_namevalue+0x2a/0xc0 [ 57.334913] ocfs2_xa_remove_entry+0x23/0xc0 [ 57.335164] ocfs2_xa_set+0x704/0xcf0 [ 57.335381] ? _raw_spin_unlock+0x1a/0x40 [ 57.335620] ? ocfs2_inode_cache_unlock+0x16/0x20 [ 57.335915] ? trace_preempt_on+0x1e/0x70 [ 57.336153] ? start_this_handle+0x16c/0x500 [ 57.336410] ? preempt_count_sub+0x50/0x80 [ 57.336656] ? _raw_read_unlock+0x20/0x40 [ 57.336906] ? start_this_handle+0x16c/0x500 [ 57.337162] ocfs2_xattr_block_set+0xa6/0x1e0 [ 57.337424] __ocfs2_xattr_set_handle+0x1fd/0x5d0 [ 57.337706] ? ocfs2_start_trans+0x13d/0x290 [ 57.337971] ocfs2_xattr_set+0xb13/0xfb0 [ 57.338207] ? dput+0x46/0x1c0 [ 57.338393] ocfs2_xattr_trusted_set+0x28/0x30 [ 57.338665] ? ocfs2_xattr_trusted_set+0x28/0x30 [ 57.338948] __vfs_removexattr+0x92/0xc0 [ 57.339182] __vfs_removexattr_locked+0xd5/0x190 [ 57.339456] ? preempt_count_sub+0x50/0x80 [ 57.339705] vfs_removexattr+0x5f/0x100 [...] Reproducer uses faultinject facility to fail ocfs2_xa_remove() -> ocfs2_xa_value_truncate() with -ENOMEM. In this case the comment mentions that we can return 0 if ocfs2_xa_cleanup_value_truncate() is going to wipe the entry anyway. But the following 'rc' check is wrong and execution flow do 'ocfs2_xa_remove_entry(loc);' twice: * 1st: in ocfs2_xa_cleanup_value_truncate(); * 2nd: returning back to ocfs2_xa_remove() instead of going to 'out'. Fix this by skipping the 2nd removal of the same entry and making syzkaller repro happy.

In the Linux kernel, the following vulnerability has been resolved: sctp: Fix null-ptr-deref in reuseport_add_sock(). syzbot reported a null-ptr-deref while accessing sk2->sk_reuseport_cb in reuseport_add_sock(). [0] The repro first creates a listener with SO_REUSEPORT. Then, it creates another listener on the same port and concurrently closes the first listener. The second listen() calls reuseport_add_sock() with the first listener as sk2, where sk2->sk_reuseport_cb is not expected to be cleared concurrently, but the close() does clear it by reuseport_detach_sock(). The problem is SCTP does not properly synchronise reuseport_alloc(), reuseport_add_sock(), and reuseport_detach_sock(). The caller of reuseport_alloc() and reuseport_{add,detach}_sock() must provide synchronisation for sockets that are classified into the same reuseport group. Otherwise, such sockets form multiple identical reuseport groups, and all groups except one would be silently dead. 1. Two sockets call listen() concurrently 2. No socket in the same group found in sctp_ep_hashtable[] 3. Two sockets call reuseport_alloc() and form two reuseport groups 4. Only one group hit first in __sctp_rcv_lookup_endpoint() receives incoming packets Also, the reported null-ptr-deref could occur. TCP/UDP guarantees that would not happen by holding the hash bucket lock. Let's apply the locking strategy to __sctp_hash_endpoint() and __sctp_unhash_endpoint(). [0]: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 UID: 0 PID: 10230 Comm: syz-executor119 Not tainted 6.10.0-syzkaller-12585-g301927d2d2eb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:reuseport_add_sock+0x27e/0x5e0 net/core/sock_reuseport.c:350 Code: 00 0f b7 5d 00 bf 01 00 00 00 89 de e8 1b a4 ff f7 83 fb 01 0f 85 a3 01 00 00 e8 6d a0 ff f7 49 8d 7e 12 48 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 4b 02 00 00 41 0f b7 5e 12 49 8d 7e 14 RSP: 0018:ffffc9000b947c98 EFLAGS: 00010202 RAX: 0000000000000002 RBX: ffff8880252ddf98 RCX: ffff888079478000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000012 RBP: 0000000000000001 R08: ffffffff8993e18d R09: 1ffffffff1fef385 R10: dffffc0000000000 R11: fffffbfff1fef386 R12: ffff8880252ddac0 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f24e45b96c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcced5f7b8 CR3: 00000000241be000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __sctp_hash_endpoint net/sctp/input.c:762 [inline] sctp_hash_endpoint+0x52a/0x600 net/sctp/input.c:790 sctp_listen_start net/sctp/socket.c:8570 [inline] sctp_inet_listen+0x767/0xa20 net/sctp/socket.c:8625 __sys_listen_socket net/socket.c:1883 [inline] __sys_listen+0x1b7/0x230 net/socket.c:1894 __do_sys_listen net/socket.c:1902 [inline] __se_sys_listen net/socket.c:1900 [inline] __x64_sys_listen+0x5a/0x70 net/socket.c:1900 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f24e46039b9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 1a 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f24e45b9228 EFLAGS: 00000246 ORIG_RAX: 0000000000000032 RAX: ffffffffffffffda RBX: 00007f24e468e428 RCX: 00007f24e46039b9 RDX: 00007f24e46039b9 RSI: 0000000000000003 RDI: 0000000000000004 RBP: 00007f24e468e420 R08: 00007f24e45b96c0 R09: 00007f24e45b96c0 R10: 00007f24e45b96c0 R11: 0000000000000246 R12: 00007f24e468e42c R13: ---truncated---

In the Linux kernel, the following vulnerability has been resolved: remoteproc: imx_rproc: Skip over memory region when node value is NULL In imx_rproc_addr_init() "nph = of_count_phandle_with_args()" just counts number of phandles. But phandles may be empty. So of_parse_phandle() in the parsing loop (0 < a < nph) may return NULL which is later dereferenced. Adjust this issue by adding NULL-return check. Found by Linux Verification Center (linuxtesting.org) with SVACE. [Fixed title to fit within the prescribed 70-75 charcters]

In the Linux kernel, the following vulnerability has been resolved: spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op() In zynq_qspi_exec_mem_op(), kzalloc() is directly used in memset(), which could lead to a NULL pointer dereference on failure of kzalloc(). Fix this bug by adding a check of tmpbuf. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_SPI_ZYNQ_QSPI=m show no new warnings, and our static analyzer no longer warns about this code.

In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Don't expose hw_counters outside of init net namespace Commit 467f432a521a ("RDMA/core: Split port and device counter sysfs attributes") accidentally almost exposed hw counters to non-init net namespaces. It didn't expose them fully, as an attempt to read any of those counters leads to a crash like this one: [42021.807566] BUG: kernel NULL pointer dereference, address: 0000000000000028 [42021.814463] #PF: supervisor read access in kernel mode [42021.819549] #PF: error_code(0x0000) - not-present page [42021.824636] PGD 0 P4D 0 [42021.827145] Oops: 0000 [#1] SMP PTI [42021.830598] CPU: 82 PID: 2843922 Comm: switchto-defaul Kdump: loaded Tainted: G S W I XXX [42021.841697] Hardware name: XXX [42021.849619] RIP: 0010:hw_stat_device_show+0x1e/0x40 [ib_core] [42021.855362] Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 49 89 d0 4c 8b 5e 20 48 8b 8f b8 04 00 00 48 81 c7 f0 fa ff ff <48> 8b 41 28 48 29 ce 48 83 c6 d0 48 c1 ee 04 69 d6 ab aa aa aa 48 [42021.873931] RSP: 0018:ffff97fe90f03da0 EFLAGS: 00010287 [42021.879108] RAX: ffff9406988a8c60 RBX: ffff940e1072d438 RCX: 0000000000000000 [42021.886169] RDX: ffff94085f1aa000 RSI: ffff93c6cbbdbcb0 RDI: ffff940c7517aef0 [42021.893230] RBP: ffff97fe90f03e70 R08: ffff94085f1aa000 R09: 0000000000000000 [42021.900294] R10: ffff94085f1aa000 R11: ffffffffc0775680 R12: ffffffff87ca2530 [42021.907355] R13: ffff940651602840 R14: ffff93c6cbbdbcb0 R15: ffff94085f1aa000 [42021.914418] FS: 00007fda1a3b9700(0000) GS:ffff94453fb80000(0000) knlGS:0000000000000000 [42021.922423] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [42021.928130] CR2: 0000000000000028 CR3: 00000042dcfb8003 CR4: 00000000003726f0 [42021.935194] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [42021.942257] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [42021.949324] Call Trace: [42021.951756] <TASK> [42021.953842] [<ffffffff86c58674>] ? show_regs+0x64/0x70 [42021.959030] [<ffffffff86c58468>] ? __die+0x78/0xc0 [42021.963874] [<ffffffff86c9ef75>] ? page_fault_oops+0x2b5/0x3b0 [42021.969749] [<ffffffff87674b92>] ? exc_page_fault+0x1a2/0x3c0 [42021.975549] [<ffffffff87801326>] ? asm_exc_page_fault+0x26/0x30 [42021.981517] [<ffffffffc0775680>] ? __pfx_show_hw_stats+0x10/0x10 [ib_core] [42021.988482] [<ffffffffc077564e>] ? hw_stat_device_show+0x1e/0x40 [ib_core] [42021.995438] [<ffffffff86ac7f8e>] dev_attr_show+0x1e/0x50 [42022.000803] [<ffffffff86a3eeb1>] sysfs_kf_seq_show+0x81/0xe0 [42022.006508] [<ffffffff86a11134>] seq_read_iter+0xf4/0x410 [42022.011954] [<ffffffff869f4b2e>] vfs_read+0x16e/0x2f0 [42022.017058] [<ffffffff869f50ee>] ksys_read+0x6e/0xe0 [42022.022073] [<ffffffff8766f1ca>] do_syscall_64+0x6a/0xa0 [42022.027441] [<ffffffff8780013b>] entry_SYSCALL_64_after_hwframe+0x78/0xe2 The problem can be reproduced using the following steps: ip netns add foo ip netns exec foo bash cat /sys/class/infiniband/mlx4_0/hw_counters/* The panic occurs because of casting the device pointer into an ib_device pointer using container_of() in hw_stat_device_show() is wrong and leads to a memory corruption. However the real problem is that hw counters should never been exposed outside of the non-init net namespace. Fix this by saving the index of the corresponding attribute group (it might be 1 or 2 depending on the presence of driver-specific attributes) and zeroing the pointer to hw_counters group for compat devices during the initialization. With this fix applied hw_counters are not available in a non-init net namespace: find /sys/class/infiniband/mlx4_0/ -name hw_counters /sys/class/infiniband/mlx4_0/ports/1/hw_counters /sys/class/infiniband/mlx4_0/ports/2/hw_counters /sys/class/infiniband/mlx4_0/hw_counters ip netns add foo ip netns exec foo bash find /sys/class/infiniband/mlx4_0/ -name hw_counters

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mvm: avoid NULL pointer dereference iwl_mvm_tx_skb_sta() and iwl_mvm_tx_mpdu() verify that the mvmvsta pointer is not NULL. It retrieves this pointer using iwl_mvm_sta_from_mac80211, which is dereferencing the ieee80211_sta pointer. If sta is NULL, iwl_mvm_sta_from_mac80211 will dereference a NULL pointer. Fix this by checking the sta pointer before retrieving the mvmsta from it. If sta is not NULL, then mvmsta isn't either.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null check for set_output_gamma in dcn30_set_output_transfer_func This commit adds a null check for the set_output_gamma function pointer in the dcn30_set_output_transfer_func function. Previously, set_output_gamma was being checked for nullity at line 386, but then it was being dereferenced without any nullity check at line 401. This could potentially lead to a null pointer dereference error if set_output_gamma is indeed null. To fix this, we now ensure that set_output_gamma is not null before dereferencing it. We do this by adding a nullity check for set_output_gamma before the call to set_output_gamma at line 401. If set_output_gamma is null, we log an error message and do not call the function. This fix prevents a potential null pointer dereference error. drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c:401 dcn30_set_output_transfer_func() error: we previously assumed 'mpc->funcs->set_output_gamma' could be null (see line 386) drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c 373 bool dcn30_set_output_transfer_func(struct dc *dc, 374 struct pipe_ctx *pipe_ctx, 375 const struct dc_stream_state *stream) 376 { 377 int mpcc_id = pipe_ctx->plane_res.hubp->inst; 378 struct mpc *mpc = pipe_ctx->stream_res.opp->ctx->dc->res_pool->mpc; 379 const struct pwl_params *params = NULL; 380 bool ret = false; 381 382 /* program OGAM or 3DLUT only for the top pipe*/ 383 if (pipe_ctx->top_pipe == NULL) { 384 /*program rmu shaper and 3dlut in MPC*/ 385 ret = dcn30_set_mpc_shaper_3dlut(pipe_ctx, stream); 386 if (ret == false && mpc->funcs->set_output_gamma) { ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ If this is NULL 387 if (stream->out_transfer_func.type == TF_TYPE_HWPWL) 388 params = &stream->out_transfer_func.pwl; 389 else if (pipe_ctx->stream->out_transfer_func.type == 390 TF_TYPE_DISTRIBUTED_POINTS && 391 cm3_helper_translate_curve_to_hw_format( 392 &stream->out_transfer_func, 393 &mpc->blender_params, false)) 394 params = &mpc->blender_params; 395 /* there are no ROM LUTs in OUTGAM */ 396 if (stream->out_transfer_func.type == TF_TYPE_PREDEFINED) 397 BREAK_TO_DEBUGGER(); 398 } 399 } 400 --> 401 mpc->funcs->set_output_gamma(mpc, mpcc_id, params); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Then it will crash 402 return ret; 403 }

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/ras: Move ras data alloc before bad page check In the rare event if eeprom has only invalid address entries, allocation is skipped, this causes following NULL pointer issue [ 547.103445] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 547.118897] #PF: supervisor read access in kernel mode [ 547.130292] #PF: error_code(0x0000) - not-present page [ 547.141689] PGD 124757067 P4D 0 [ 547.148842] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 547.158504] CPU: 49 PID: 8167 Comm: cat Tainted: G OE 6.8.0-38-generic #38-Ubuntu [ 547.177998] Hardware name: Supermicro AS -8126GS-TNMR/H14DSG-OD, BIOS 1.7 09/12/2025 [ 547.195178] RIP: 0010:amdgpu_ras_sysfs_badpages_read+0x2f2/0x5d0 [amdgpu] [ 547.210375] Code: e8 63 78 82 c0 45 31 d2 45 3b 75 08 48 8b 45 a0 73 44 44 89 f1 48 8b 7d 88 48 89 ca 48 c1 e2 05 48 29 ca 49 8b 4d 00 48 01 d1 <48> 83 79 10 00 74 17 49 63 f2 48 8b 49 08 41 83 c2 01 48 8d 34 76 [ 547.252045] RSP: 0018:ffa0000067287ac0 EFLAGS: 00010246 [ 547.263636] RAX: ff11000167c28130 RBX: ff11000127600000 RCX: 0000000000000000 [ 547.279467] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ff11000125b1c800 [ 547.295298] RBP: ffa0000067287b50 R08: 0000000000000000 R09: 0000000000000000 [ 547.311129] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 547.326959] R13: ff11000217b1de00 R14: 0000000000000000 R15: 0000000000000092 [ 547.342790] FS: 0000746e59d14740(0000) GS:ff11017dfda80000(0000) knlGS:0000000000000000 [ 547.360744] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 547.373489] CR2: 0000000000000010 CR3: 000000019585e001 CR4: 0000000000f71ef0 [ 547.389321] PKRU: 55555554 [ 547.395316] Call Trace: [ 547.400737] <TASK> [ 547.405386] ? show_regs+0x6d/0x80 [ 547.412929] ? __die+0x24/0x80 [ 547.419697] ? page_fault_oops+0x99/0x1b0 [ 547.428588] ? do_user_addr_fault+0x2ee/0x6b0 [ 547.438249] ? exc_page_fault+0x83/0x1b0 [ 547.446949] ? asm_exc_page_fault+0x27/0x30 [ 547.456225] ? amdgpu_ras_sysfs_badpages_read+0x2f2/0x5d0 [amdgpu] [ 547.470040] ? mas_wr_modify+0xcd/0x140 [ 547.478548] sysfs_kf_bin_read+0x63/0xb0 [ 547.487248] kernfs_file_read_iter+0xa1/0x190 [ 547.496909] kernfs_fop_read_iter+0x25/0x40 [ 547.506182] vfs_read+0x255/0x390 This also result in space left assigned to negative values. Moving data alloc call before bad page check resolves both the issue.

In the Linux kernel, the following vulnerability has been resolved: drm/msm/a6xx: move preempt_prepare_postamble after error check Move the call to preempt_prepare_postamble() after verifying that preempt_postamble_ptr is valid. If preempt_postamble_ptr is NULL, dereferencing it in preempt_prepare_postamble() would lead to a crash. This change avoids calling the preparation function when the postamble allocation has failed, preventing potential NULL pointer dereference and ensuring proper error handling. Patchwork: https://patchwork.freedesktop.org/patch/687659/

In the Linux kernel, the following vulnerability has been resolved: ACPICA: Avoid walking the Namespace if start_node is NULL Although commit 0c9992315e73 ("ACPICA: Avoid walking the ACPI Namespace if it is not there") fixed the situation when both start_node and acpi_gbl_root_node are NULL, the Linux kernel mainline now still crashed on Honor Magicbook 14 Pro [1]. That happens due to the access to the member of parent_node in acpi_ns_get_next_node(). The NULL pointer dereference will always happen, no matter whether or not the start_node is equal to ACPI_ROOT_OBJECT, so move the check of start_node being NULL out of the if block. Unfortunately, all the attempts to contact Honor have failed, they refused to provide any technical support for Linux. The bad DSDT table's dump could be found on GitHub [2]. DMI: HONOR FMB-P/FMB-P-PCB, BIOS 1.13 05/08/2025 [ rjw: Subject adjustment, changelog edits ]

In the Linux kernel, the following vulnerability has been resolved: net: qrtr: Drop the MHI auto_queue feature for IPCR DL channels MHI stack offers the 'auto_queue' feature, which allows the MHI stack to auto queue the buffers for the RX path (DL channel). Though this feature simplifies the client driver design, it introduces race between the client drivers and the MHI stack. For instance, with auto_queue, the 'dl_callback' for the DL channel may get called before the client driver is fully probed. This means, by the time the dl_callback gets called, the client driver's structures might not be initialized, leading to NULL ptr dereference. Currently, the drivers have to workaround this issue by initializing the internal structures before calling mhi_prepare_for_transfer_autoqueue(). But even so, there is a chance that the client driver's internal code path may call the MHI queue APIs before mhi_prepare_for_transfer_autoqueue() is called, leading to similar NULL ptr dereference. This issue has been reported on the Qcom X1E80100 CRD machines affecting boot. So to properly fix all these races, drop the MHI 'auto_queue' feature altogether and let the client driver (QRTR) manage the RX buffers manually. In the QRTR driver, queue the RX buffers based on the ring length during probe and recycle the buffers in 'dl_callback' once they are consumed. This also warrants removing the setting of 'auto_queue' flag from controller drivers. Currently, this 'auto_queue' feature is only enabled for IPCR DL channel. So only the QRTR client driver requires the modification.

In the Linux kernel, the following vulnerability has been resolved: drm/ttm: Avoid NULL pointer deref for evicted BOs It is possible for a BO to exist that is not currently associated with a resource, e.g. because it has been evicted. When devcoredump tries to read the contents of all BOs for dumping, we need to expect this as well -- in this case, ENODATA is recorded instead of the buffer contents.

In the Linux kernel, the following vulnerability has been resolved: btrfs: make cow_file_range_inline() honor locked_page on error The btrfs buffered write path runs through __extent_writepage() which has some tricky return value handling for writepage_delalloc(). Specifically, when that returns 1, we exit, but for other return values we continue and end up calling btrfs_folio_end_all_writers(). If the folio has been unlocked (note that we check the PageLocked bit at the start of __extent_writepage()), this results in an assert panic like this one from syzbot: BTRFS: error (device loop0 state EAL) in free_log_tree:3267: errno=-5 IO failure BTRFS warning (device loop0 state EAL): Skipping commit of aborted transaction. BTRFS: error (device loop0 state EAL) in cleanup_transaction:2018: errno=-5 IO failure assertion failed: folio_test_locked(folio), in fs/btrfs/subpage.c:871 ------------[ cut here ]------------ kernel BUG at fs/btrfs/subpage.c:871! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 PID: 5090 Comm: syz-executor225 Not tainted 6.10.0-syzkaller-05505-gb1bc554e009e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:btrfs_folio_end_all_writers+0x55b/0x610 fs/btrfs/subpage.c:871 Code: e9 d3 fb ff ff e8 25 22 c2 fd 48 c7 c7 c0 3c 0e 8c 48 c7 c6 80 3d 0e 8c 48 c7 c2 60 3c 0e 8c b9 67 03 00 00 e8 66 47 ad 07 90 <0f> 0b e8 6e 45 b0 07 4c 89 ff be 08 00 00 00 e8 21 12 25 fe 4c 89 RSP: 0018:ffffc900033d72e0 EFLAGS: 00010246 RAX: 0000000000000045 RBX: 00fff0000000402c RCX: 663b7a08c50a0a00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffffc900033d73b0 R08: ffffffff8176b98c R09: 1ffff9200067adfc R10: dffffc0000000000 R11: fffff5200067adfd R12: 0000000000000001 R13: dffffc0000000000 R14: 0000000000000000 R15: ffffea0001cbee80 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5f076012f8 CR3: 000000000e134000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __extent_writepage fs/btrfs/extent_io.c:1597 [inline] extent_write_cache_pages fs/btrfs/extent_io.c:2251 [inline] btrfs_writepages+0x14d7/0x2760 fs/btrfs/extent_io.c:2373 do_writepages+0x359/0x870 mm/page-writeback.c:2656 filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397 __filemap_fdatawrite_range mm/filemap.c:430 [inline] __filemap_fdatawrite mm/filemap.c:436 [inline] filemap_flush+0xdf/0x130 mm/filemap.c:463 btrfs_release_file+0x117/0x130 fs/btrfs/file.c:1547 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:222 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27f0 kernel/exit.c:877 do_group_exit+0x207/0x2c0 kernel/exit.c:1026 __do_sys_exit_group kernel/exit.c:1037 [inline] __se_sys_exit_group kernel/exit.c:1035 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5f075b70c9 Code: Unable to access opcode bytes at 0x7f5f075b709f. I was hitting the same issue by doing hundreds of accelerated runs of generic/475, which also hits IO errors by design. I instrumented that reproducer with bpftrace and found that the undesirable folio_unlock was coming from the following callstack: folio_unlock+5 __process_pages_contig+475 cow_file_range_inline.constprop.0+230 cow_file_range+803 btrfs_run_delalloc_range+566 writepage_delalloc+332 __extent_writepage # inlined in my stacktrace, but I added it here extent_write_cache_pages+622 Looking at the bisected-to pa ---truncated---

In the Linux kernel, the following vulnerability has been resolved: tracing: Do not register unsupported perf events Synthetic events currently do not have a function to register perf events. This leads to calling the tracepoint register functions with a NULL function pointer which triggers: ------------[ cut here ]------------ WARNING: kernel/tracepoint.c:175 at tracepoint_add_func+0x357/0x370, CPU#2: perf/2272 Modules linked in: kvm_intel kvm irqbypass CPU: 2 UID: 0 PID: 2272 Comm: perf Not tainted 6.18.0-ftest-11964-ge022764176fc-dirty #323 PREEMPTLAZY Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 RIP: 0010:tracepoint_add_func+0x357/0x370 Code: 28 9c e8 4c 0b f5 ff eb 0f 4c 89 f7 48 c7 c6 80 4d 28 9c e8 ab 89 f4 ff 31 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc <0f> 0b 49 c7 c6 ea ff ff ff e9 ee fe ff ff 0f 0b e9 f9 fe ff ff 0f RSP: 0018:ffffabc0c44d3c40 EFLAGS: 00010246 RAX: 0000000000000001 RBX: ffff9380aa9e4060 RCX: 0000000000000000 RDX: 000000000000000a RSI: ffffffff9e1d4a98 RDI: ffff937fcf5fd6c8 RBP: 0000000000000001 R08: 0000000000000007 R09: ffff937fcf5fc780 R10: 0000000000000003 R11: ffffffff9c193910 R12: 000000000000000a R13: ffffffff9e1e5888 R14: 0000000000000000 R15: ffffabc0c44d3c78 FS: 00007f6202f5f340(0000) GS:ffff93819f00f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d3162281a8 CR3: 0000000106a56003 CR4: 0000000000172ef0 Call Trace: <TASK> tracepoint_probe_register+0x5d/0x90 synth_event_reg+0x3c/0x60 perf_trace_event_init+0x204/0x340 perf_trace_init+0x85/0xd0 perf_tp_event_init+0x2e/0x50 perf_try_init_event+0x6f/0x230 ? perf_event_alloc+0x4bb/0xdc0 perf_event_alloc+0x65a/0xdc0 __se_sys_perf_event_open+0x290/0x9f0 do_syscall_64+0x93/0x7b0 ? entry_SYSCALL_64_after_hwframe+0x76/0x7e ? trace_hardirqs_off+0x53/0xc0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Instead, have the code return -ENODEV, which doesn't warn and has perf error out with: # perf record -e synthetic:futex_wait Error: The sys_perf_event_open() syscall returned with 19 (No such device) for event (synthetic:futex_wait). "dmesg | grep -i perf" may provide additional information. Ideally perf should support synthetic events, but for now just fix the warning. The support can come later.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix NULL pointer issue buffer funcs If SDMA block not enabled, buffer_funcs will not initialize, fix the null pointer issue if buffer_funcs not initialized.

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: svcauth_gss: avoid NULL deref on zero length gss_token in gss_read_proxy_verf A zero length gss_token results in pages == 0 and in_token->pages[0] is NULL. The code unconditionally evaluates page_address(in_token->pages[0]) for the initial memcpy, which can dereference NULL even when the copy length is 0. Guard the first memcpy so it only runs when length > 0.

In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: Avoid creating sub-groups asynchronously The asynchronous creation of sub-groups by a delayed work could lead to a NULL pointer dereference when the driver directory is removed before the work completes. The crash can be easily reproduced with the following commands: # cd /sys/kernel/config/pci_ep/functions/pci_epf_test # for i in {1..20}; do mkdir test && rmdir test; done BUG: kernel NULL pointer dereference, address: 0000000000000088 ... Call Trace: configfs_register_group+0x3d/0x190 pci_epf_cfs_work+0x41/0x110 process_one_work+0x18f/0x350 worker_thread+0x25a/0x3a0 Fix this issue by using configfs_add_default_group() API which does not have the deadlock problem as configfs_register_group() and does not require the delayed work handler. [mani: slightly reworded the description and added stable list]

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix NULL dereference on root when tracing inode eviction When evicting an inode the first thing we do is to setup tracing for it, which implies fetching the root's id. But in btrfs_evict_inode() the root might be NULL, as implied in the next check that we do in btrfs_evict_inode(). Hence, we either should set the ->root_objectid to 0 in case the root is NULL, or we move tracing setup after checking that the root is not NULL. Setting the rootid to 0 at least gives us the possibility to trace this call even in the case when the root is NULL, so that's the solution taken here.

In the Linux kernel, the following vulnerability has been resolved: drm/msm/dpu: Add missing NULL pointer check for pingpong interface It is checked almost always in dpu_encoder_phys_wb_setup_ctl(), but in a single place the check is missing. Also use convenient locals instead of phys_enc->* where available. Patchwork: https://patchwork.freedesktop.org/patch/693860/

In the Linux kernel, the following vulnerability has been resolved: smb/server: fix potential null-ptr-deref of lease_ctx_info in smb2_open() null-ptr-deref will occur when (req_op_level == SMB2_OPLOCK_LEVEL_LEASE) and parse_lease_state() return NULL. Fix this by check if 'lease_ctx_info' is NULL. Additionally, remove the redundant parentheses in parse_durable_handle_context().

In the Linux kernel, the following vulnerability has been resolved: md/raid5: fix possible null-pointer dereferences in raid5_store_group_thread_cnt() The variable mddev->private is first assigned to conf and then checked: conf = mddev->private; if (!conf) ... If conf is NULL, then mddev->private is also NULL. In this case, null-pointer dereferences can occur when calling raid5_quiesce(): raid5_quiesce(mddev, true); raid5_quiesce(mddev, false); since mddev->private is assigned to conf again in raid5_quiesce(), and conf is dereferenced in several places, for example: conf->quiesce = 0; wake_up(&conf->wait_for_quiescent); To fix this issue, the function should unlock mddev and return before invoking raid5_quiesce() when conf is NULL, following the existing pattern in raid5_change_consistency_policy().

In the Linux kernel before 5.16.3, drivers/scsi/ufs/ufs-mediatek.c misinterprets the regulator_get return value (expects it to be NULL in the error case, whereas it is actually an error pointer).

In the Linux kernel, the following vulnerability has been resolved: drm/msm: adreno: fix deferencing ifpc_reglist when not declared On plaforms with an a7xx GPU not supporting IFPC, the ifpc_reglist if still deferenced in a7xx_patch_pwrup_reglist() which causes a kernel crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 ... pc : a6xx_hw_init+0x155c/0x1e4c [msm] lr : a6xx_hw_init+0x9a8/0x1e4c [msm] ... Call trace: a6xx_hw_init+0x155c/0x1e4c [msm] (P) msm_gpu_hw_init+0x58/0x88 [msm] adreno_load_gpu+0x94/0x1fc [msm] msm_open+0xe4/0xf4 [msm] drm_file_alloc+0x1a0/0x2e4 [drm] drm_client_init+0x7c/0x104 [drm] drm_fbdev_client_setup+0x94/0xcf0 [drm_client_lib] drm_client_setup+0xb4/0xd8 [drm_client_lib] msm_drm_kms_post_init+0x2c/0x3c [msm] msm_drm_init+0x1a4/0x228 [msm] msm_drm_bind+0x30/0x3c [msm] ... Check the validity of ifpc_reglist before deferencing the table to setup the register values. Patchwork: https://patchwork.freedesktop.org/patch/688944/

In the Linux kernel before 6.1.2, kernel/module/decompress.c misinterprets the module_get_next_page return value (expects it to be NULL in the error case, whereas it is actually an error pointer).

In the Linux kernel, the following vulnerability has been resolved: misc: bcm_vk: Fix possible null-pointer dereferences in bcm_vk_read() In the function bcm_vk_read(), the pointer entry is checked, indicating that it can be NULL. If entry is NULL and rc is set to -EMSGSIZE, the following code may cause null-pointer dereferences: struct vk_msg_blk tmp_msg = entry->to_h_msg[0]; set_msg_id(&tmp_msg, entry->usr_msg_id); tmp_msg.size = entry->to_h_blks - 1; To prevent these possible null-pointer dereferences, copy to_h_msg, usr_msg_id, and to_h_blks from iter into temporary variables, and return these temporary variables to the application instead of accessing them through a potentially NULL entry.

In the Linux kernel before 6.2, mm/memory-tiers.c misinterprets the alloc_memory_type return value (expects it to be NULL in the error case, whereas it is actually an error pointer). NOTE: this is disputed by third parties because there are no realistic cases in which a user can cause the alloc_memory_type error case to be reached.

In the Linux kernel before 5.16.3, drivers/usb/dwc3/dwc3-qcom.c misinterprets the dwc3_qcom_create_urs_usb_platdev return value (expects it to be NULL in the error case, whereas it is actually an error pointer).

In the Linux kernel, the following vulnerability has been resolved: seg6: fix parameter passing when calling NF_HOOK() in End.DX4 and End.DX6 behaviors input_action_end_dx4() and input_action_end_dx6() are called NF_HOOK() for PREROUTING hook, in PREROUTING hook, we should passing a valid indev, and a NULL outdev to NF_HOOK(), otherwise may trigger a NULL pointer dereference, as below: [74830.647293] BUG: kernel NULL pointer dereference, address: 0000000000000090 [74830.655633] #PF: supervisor read access in kernel mode [74830.657888] #PF: error_code(0x0000) - not-present page [74830.659500] PGD 0 P4D 0 [74830.660450] Oops: 0000 [#1] PREEMPT SMP PTI ... [74830.664953] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [74830.666569] RIP: 0010:rpfilter_mt+0x44/0x15e [ipt_rpfilter] ... [74830.689725] Call Trace: [74830.690402] <IRQ> [74830.690953] ? show_trace_log_lvl+0x1c4/0x2df [74830.692020] ? show_trace_log_lvl+0x1c4/0x2df [74830.693095] ? ipt_do_table+0x286/0x710 [ip_tables] [74830.694275] ? __die_body.cold+0x8/0xd [74830.695205] ? page_fault_oops+0xac/0x140 [74830.696244] ? exc_page_fault+0x62/0x150 [74830.697225] ? asm_exc_page_fault+0x22/0x30 [74830.698344] ? rpfilter_mt+0x44/0x15e [ipt_rpfilter] [74830.699540] ipt_do_table+0x286/0x710 [ip_tables] [74830.700758] ? ip6_route_input+0x19d/0x240 [74830.701752] nf_hook_slow+0x3f/0xb0 [74830.702678] input_action_end_dx4+0x19b/0x1e0 [74830.703735] ? input_action_end_t+0xe0/0xe0 [74830.704734] seg6_local_input_core+0x2d/0x60 [74830.705782] lwtunnel_input+0x5b/0xb0 [74830.706690] __netif_receive_skb_one_core+0x63/0xa0 [74830.707825] process_backlog+0x99/0x140 [74830.709538] __napi_poll+0x2c/0x160 [74830.710673] net_rx_action+0x296/0x350 [74830.711860] __do_softirq+0xcb/0x2ac [74830.713049] do_softirq+0x63/0x90 input_action_end_dx4() passing a NULL indev to NF_HOOK(), and finally trigger a NULL dereference in rpfilter_mt()->rpfilter_is_loopback(): static bool rpfilter_is_loopback(const struct sk_buff *skb, const struct net_device *in) { // in is NULL return skb->pkt_type == PACKET_LOOPBACK || in->flags & IFF_LOOPBACK; }

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btnxpuart: Fix Null pointer dereference in btnxpuart_flush() This adds a check before freeing the rx->skb in flush and close functions to handle the kernel crash seen while removing driver after FW download fails or before FW download completes. dmesg log: [ 54.634586] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000080 [ 54.643398] Mem abort info: [ 54.646204] ESR = 0x0000000096000004 [ 54.649964] EC = 0x25: DABT (current EL), IL = 32 bits [ 54.655286] SET = 0, FnV = 0 [ 54.658348] EA = 0, S1PTW = 0 [ 54.661498] FSC = 0x04: level 0 translation fault [ 54.666391] Data abort info: [ 54.669273] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 54.674768] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 54.674771] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 54.674775] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000048860000 [ 54.674780] [0000000000000080] pgd=0000000000000000, p4d=0000000000000000 [ 54.703880] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 54.710152] Modules linked in: btnxpuart(-) overlay fsl_jr_uio caam_jr caamkeyblob_desc caamhash_desc caamalg_desc crypto_engine authenc libdes crct10dif_ce polyval_ce polyval_generic snd_soc_imx_spdif snd_soc_imx_card snd_soc_ak5558 snd_soc_ak4458 caam secvio error snd_soc_fsl_micfil snd_soc_fsl_spdif snd_soc_fsl_sai snd_soc_fsl_utils imx_pcm_dma gpio_ir_recv rc_core sch_fq_codel fuse [ 54.744357] CPU: 3 PID: 72 Comm: kworker/u9:0 Not tainted 6.6.3-otbr-g128004619037 #2 [ 54.744364] Hardware name: FSL i.MX8MM EVK board (DT) [ 54.744368] Workqueue: hci0 hci_power_on [ 54.757244] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 54.757249] pc : kfree_skb_reason+0x18/0xb0 [ 54.772299] lr : btnxpuart_flush+0x40/0x58 [btnxpuart] [ 54.782921] sp : ffff8000805ebca0 [ 54.782923] x29: ffff8000805ebca0 x28: ffffa5c6cf1869c0 x27: ffffa5c6cf186000 [ 54.782931] x26: ffff377b84852400 x25: ffff377b848523c0 x24: ffff377b845e7230 [ 54.782938] x23: ffffa5c6ce8dbe08 x22: ffffa5c6ceb65410 x21: 00000000ffffff92 [ 54.782945] x20: ffffa5c6ce8dbe98 x19: ffffffffffffffac x18: ffffffffffffffff [ 54.807651] x17: 0000000000000000 x16: ffffa5c6ce2824ec x15: ffff8001005eb857 [ 54.821917] x14: 0000000000000000 x13: ffffa5c6cf1a02e0 x12: 0000000000000642 [ 54.821924] x11: 0000000000000040 x10: ffffa5c6cf19d690 x9 : ffffa5c6cf19d688 [ 54.821931] x8 : ffff377b86000028 x7 : 0000000000000000 x6 : 0000000000000000 [ 54.821938] x5 : ffff377b86000000 x4 : 0000000000000000 x3 : 0000000000000000 [ 54.843331] x2 : 0000000000000000 x1 : 0000000000000002 x0 : ffffffffffffffac [ 54.857599] Call trace: [ 54.857601] kfree_skb_reason+0x18/0xb0 [ 54.863878] btnxpuart_flush+0x40/0x58 [btnxpuart] [ 54.863888] hci_dev_open_sync+0x3a8/0xa04 [ 54.872773] hci_power_on+0x54/0x2e4 [ 54.881832] process_one_work+0x138/0x260 [ 54.881842] worker_thread+0x32c/0x438 [ 54.881847] kthread+0x118/0x11c [ 54.881853] ret_from_fork+0x10/0x20 [ 54.896406] Code: a9be7bfd 910003fd f9000bf3 aa0003f3 (b940d400) [ 54.896410] ---[ end trace 0000000000000000 ]---

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 before 5.19, drivers/gpu/drm/arm/malidp_planes.c misinterprets the get_sg_table return value (expects it to be NULL in the error case, whereas it is actually an error pointer).

In the Linux kernel before 5.16.3, drivers/bluetooth/hci_qca.c misinterprets the devm_gpiod_get_index_optional return value (expects it to be NULL in the error case, whereas it is actually an error pointer).

In the Linux kernel before 5.17, drivers/phy/tegra/xusb.c mishandles the tegra_xusb_find_port_node return value. Callers expect NULL in the error case, but an error pointer is used.

In the Linux kernel before 5.15.13, drivers/net/ethernet/mellanox/mlx5/core/steering/dr_domain.c misinterprets the mlx5_get_uars_page return value (expects it to be NULL in the error case, whereas it is actually an error pointer).

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: 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

A null pointer dereference issue was found in can protocol in net/can/af_can.c in the Linux before Linux. ml_priv may not be initialized in the receive path of CAN frames. A local user could use this flaw to crash the system or potentially cause a denial of service.

In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Fix missing initialisation affecting gcm-aes-s390 Fix af_alg_alloc_areq() to initialise areq->first_rsgl.sgl.sgt.sgl to point to the scatterlist array in areq->first_rsgl.sgl.sgl. Without this, the gcm-aes-s390 driver will oops when it tries to do gcm_walk_start() on req->dst because req->dst is set to the value of areq->first_rsgl.sgl.sgl by _aead_recvmsg() calling aead_request_set_crypt(). The problem comes if an empty ciphertext is passed: the loop in af_alg_get_rsgl() just passes straight out and doesn't set areq->first_rsgl up. This isn't a problem on x86_64 using gcmaes_crypt_by_sg() because, as far as I can tell, that ignores req->dst and only uses req->src[*]. [*] Is this a bug in aesni-intel_glue.c? The s390x oops looks something like: Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 0000000a00000000 TEID: 0000000a00000803 Fault in home space mode while using kernel ASCE. AS:00000000a43a0007 R3:0000000000000024 Oops: 003b ilc:2 [#1] SMP ... Call Trace: [<000003ff7fc3d47e>] gcm_walk_start+0x16/0x28 [aes_s390] [<00000000a2a342f2>] crypto_aead_decrypt+0x9a/0xb8 [<00000000a2a60888>] aead_recvmsg+0x478/0x698 [<00000000a2e519a0>] sock_recvmsg+0x70/0xb0 [<00000000a2e51a56>] sock_read_iter+0x76/0xa0 [<00000000a273e066>] vfs_read+0x26e/0x2a8 [<00000000a273e8c4>] ksys_read+0xbc/0x100 [<00000000a311d808>] __do_syscall+0x1d0/0x1f8 [<00000000a312ff30>] system_call+0x70/0x98 Last Breaking-Event-Address: [<000003ff7fc3e6b4>] gcm_aes_crypt+0x104/0xa68 [aes_s390]

In the Linux kernel, the following vulnerability has been resolved: perf/x86: Move event pointer setup earlier in x86_pmu_enable() A production AMD EPYC system crashed with a NULL pointer dereference in the PMU NMI handler: BUG: kernel NULL pointer dereference, address: 0000000000000198 RIP: x86_perf_event_update+0xc/0xa0 Call Trace: <NMI> amd_pmu_v2_handle_irq+0x1a6/0x390 perf_event_nmi_handler+0x24/0x40 The faulting instruction is `cmpq $0x0, 0x198(%rdi)` with RDI=0, corresponding to the `if (unlikely(!hwc->event_base))` check in x86_perf_event_update() where hwc = &event->hw and event is NULL. drgn inspection of the vmcore on CPU 106 showed a mismatch between cpuc->active_mask and cpuc->events[]: active_mask: 0x1e (bits 1, 2, 3, 4) events[1]: 0xff1100136cbd4f38 (valid) events[2]: 0x0 (NULL, but active_mask bit 2 set) events[3]: 0xff1100076fd2cf38 (valid) events[4]: 0xff1100079e990a90 (valid) The event that should occupy events[2] was found in event_list[2] with hw.idx=2 and hw.state=0x0, confirming x86_pmu_start() had run (which clears hw.state and sets active_mask) but events[2] was never populated. Another event (event_list[0]) had hw.state=0x7 (STOPPED|UPTODATE|ARCH), showing it was stopped when the PMU rescheduled events, confirming the throttle-then-reschedule sequence occurred. The root cause is commit 7e772a93eb61 ("perf/x86: Fix NULL event access and potential PEBS record loss") which moved the cpuc->events[idx] assignment out of x86_pmu_start() and into step 2 of x86_pmu_enable(), after the PERF_HES_ARCH check. This broke any path that calls pmu->start() without going through x86_pmu_enable() -- specifically the unthrottle path: perf_adjust_freq_unthr_events() -> perf_event_unthrottle_group() -> perf_event_unthrottle() -> event->pmu->start(event, 0) -> x86_pmu_start() // sets active_mask but not events[] The race sequence is: 1. A group of perf events overflows, triggering group throttle via perf_event_throttle_group(). All events are stopped: active_mask bits cleared, events[] preserved (x86_pmu_stop no longer clears events[] after commit 7e772a93eb61). 2. While still throttled (PERF_HES_STOPPED), x86_pmu_enable() runs due to other scheduling activity. Stopped events that need to move counters get PERF_HES_ARCH set and events[old_idx] cleared. In step 2 of x86_pmu_enable(), PERF_HES_ARCH causes these events to be skipped -- events[new_idx] is never set. 3. The timer tick unthrottles the group via pmu->start(). Since commit 7e772a93eb61 removed the events[] assignment from x86_pmu_start(), active_mask[new_idx] is set but events[new_idx] remains NULL. 4. A PMC overflow NMI fires. The handler iterates active counters, finds active_mask[2] set, reads events[2] which is NULL, and crashes dereferencing it. Move the cpuc->events[hwc->idx] assignment in x86_pmu_enable() to before the PERF_HES_ARCH check, so that events[] is populated even for events that are not immediately started. This ensures the unthrottle path via pmu->start() always finds a valid event pointer.