In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Reject sk_msg egress redirects to non-TCP sockets With a SOCKMAP/SOCKHASH map and an sk_msg program user can steer messages sent from one TCP socket (s1) to actually egress from another TCP socket (s2): tcp_bpf_sendmsg(s1) // = sk_prot->sendmsg tcp_bpf_send_verdict(s1) // __SK_REDIRECT case tcp_bpf_sendmsg_redir(s2) tcp_bpf_push_locked(s2) tcp_bpf_push(s2) tcp_rate_check_app_limited(s2) // expects tcp_sock tcp_sendmsg_locked(s2) // ditto There is a hard-coded assumption in the call-chain, that the egress socket (s2) is a TCP socket. However in commit 122e6c79efe1 ("sock_map: Update sock type checks for UDP") we have enabled redirects to non-TCP sockets. This was done for the sake of BPF sk_skb programs. There was no indention to support sk_msg send-to-egress use case. As a result, attempts to send-to-egress through a non-TCP socket lead to a crash due to invalid downcast from sock to tcp_sock: BUG: kernel NULL pointer dereference, address: 000000000000002f ... Call Trace: <TASK> ? show_regs+0x60/0x70 ? __die+0x1f/0x70 ? page_fault_oops+0x80/0x160 ? do_user_addr_fault+0x2d7/0x800 ? rcu_is_watching+0x11/0x50 ? exc_page_fault+0x70/0x1c0 ? asm_exc_page_fault+0x27/0x30 ? tcp_tso_segs+0x14/0xa0 tcp_write_xmit+0x67/0xce0 __tcp_push_pending_frames+0x32/0xf0 tcp_push+0x107/0x140 tcp_sendmsg_locked+0x99f/0xbb0 tcp_bpf_push+0x19d/0x3a0 tcp_bpf_sendmsg_redir+0x55/0xd0 tcp_bpf_send_verdict+0x407/0x550 tcp_bpf_sendmsg+0x1a1/0x390 inet_sendmsg+0x6a/0x70 sock_sendmsg+0x9d/0xc0 ? sockfd_lookup_light+0x12/0x80 __sys_sendto+0x10e/0x160 ? syscall_enter_from_user_mode+0x20/0x60 ? __this_cpu_preempt_check+0x13/0x20 ? lockdep_hardirqs_on+0x82/0x110 __x64_sys_sendto+0x1f/0x30 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Reject selecting a non-TCP sockets as redirect target from a BPF sk_msg program to prevent the crash. When attempted, user will receive an EACCES error from send/sendto/sendmsg() syscall.

A flaw null pointer dereference in the Linux kernel UDF file system functionality was found in the way user triggers udf_file_write_iter function for the malicious UDF image. A local user could use this flaw to crash the system. Actual from Linux kernel 4.2-rc1 till 5.17-rc2.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt2701: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: cxl/mem: Fix shutdown order Ira reports that removing cxl_mock_mem causes a crash with the following trace: BUG: kernel NULL pointer dereference, address: 0000000000000044 [..] RIP: 0010:cxl_region_decode_reset+0x7f/0x180 [cxl_core] [..] Call Trace: <TASK> cxl_region_detach+0xe8/0x210 [cxl_core] cxl_decoder_kill_region+0x27/0x40 [cxl_core] cxld_unregister+0x29/0x40 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 device_unregister+0x13/0x60 devm_release_action+0x4d/0x90 ? __pfx_unregister_port+0x10/0x10 [cxl_core] delete_endpoint+0x121/0x130 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 ? lock_release+0x142/0x290 cdev_device_del+0x15/0x50 cxl_memdev_unregister+0x54/0x70 [cxl_core] This crash is due to the clearing out the cxl_memdev's driver context (@cxlds) before the subsystem is done with it. This is ultimately due to the region(s), that this memdev is a member, being torn down and expecting to be able to de-reference @cxlds, like here: static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) ... if (cxlds->rcd) goto endpoint_reset; ... Fix it by keeping the driver context valid until memdev-device unregistration, and subsequently the entire stack of related dependencies, unwinds.

In the Linux kernel, the following vulnerability has been resolved: tls: fix NULL deref on tls_sw_splice_eof() with empty record syzkaller discovered that if tls_sw_splice_eof() is executed as part of sendfile() when the plaintext/ciphertext sk_msg are empty, the send path gets confused because the empty ciphertext buffer does not have enough space for the encryption overhead. This causes tls_push_record() to go on the `split = true` path (which is only supposed to be used when interacting with an attached BPF program), and then get further confused and hit the tls_merge_open_record() path, which then assumes that there must be at least one populated buffer element, leading to a NULL deref. It is possible to have empty plaintext/ciphertext buffers if we previously bailed from tls_sw_sendmsg_locked() via the tls_trim_both_msgs() path. tls_sw_push_pending_record() already handles this case correctly; let's do the same check in tls_sw_splice_eof().

In the Linux kernel, the following vulnerability has been resolved: thermal: core: Fix NULL pointer dereference in zone registration error path If device_register() in thermal_zone_device_register_with_trips() returns an error, the tz variable is set to NULL and subsequently dereferenced in kfree(tz->tzp). Commit adc8749b150c ("thermal/drivers/core: Use put_device() if device_register() fails") added the tz = NULL assignment in question to avoid a possible double-free after dropping the reference to the zone device. However, after commit 4649620d9404 ("thermal: core: Make thermal_zone_device_unregister() return after freeing the zone"), that assignment has become redundant, because dropping the reference to the zone device does not cause the zone object to be freed any more. Drop it to address the NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: media: vidtv: mux: Add check and kfree for kstrdup Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference. Moreover, use kfree() in the later error handling in order to avoid memory leak.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Avoid NULL dereference of timing generator [Why & How] Check whether assigned timing generator is NULL or not before accessing its funcs to prevent NULL dereference.

In the Linux kernel, the following vulnerability has been resolved: drm/msm: another fix for the headless Adreno GPU Fix another oops reproducible when rebooting the board with the Adreno GPU working in the headless mode (e.g. iMX platforms). Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read [00000000] *pgd=74936831, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] ARM CPU: 0 PID: 51 Comm: reboot Not tainted 6.2.0-rc1-dirty #11 Hardware name: Freescale i.MX53 (Device Tree Support) PC is at msm_atomic_commit_tail+0x50/0x970 LR is at commit_tail+0x9c/0x188 pc : [<c06aa430>] lr : [<c067a214>] psr: 600e0013 sp : e0851d30 ip : ee4eb7eb fp : 00090acc r10: 00000058 r9 : c2193014 r8 : c4310000 r7 : c4759380 r6 : 07bef61d r5 : 00000000 r4 : 00000000 r3 : c44cc440 r2 : 00000000 r1 : 00000000 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 74910019 DAC: 00000051 Register r0 information: NULL pointer Register r1 information: NULL pointer Register r2 information: NULL pointer Register r3 information: slab kmalloc-1k start c44cc400 pointer offset 64 size 1024 Register r4 information: NULL pointer Register r5 information: NULL pointer Register r6 information: non-paged memory Register r7 information: slab kmalloc-128 start c4759380 pointer offset 0 size 128 Register r8 information: slab kmalloc-2k start c4310000 pointer offset 0 size 2048 Register r9 information: non-slab/vmalloc memory Register r10 information: non-paged memory Register r11 information: non-paged memory Register r12 information: non-paged memory Process reboot (pid: 51, stack limit = 0xc80046d9) Stack: (0xe0851d30 to 0xe0852000) 1d20: c4759380 fbd77200 000005ff 002b9c70 1d40: c4759380 c4759380 00000000 07bef61d 00000600 c0d6fe7c c2193014 00000058 1d60: 00090acc c067a214 00000000 c4759380 c4310000 00000000 c44cc854 c067a89c 1d80: 00000000 00000000 00000000 c4310468 00000000 c4759380 c4310000 c4310468 1da0: c4310470 c0643258 c4759380 00000000 00000000 c0c4ee24 00000000 c44cc810 1dc0: 00000000 c0c4ee24 00000000 c44cc810 00000000 0347d2a8 e0851e00 e0851e00 1de0: c4759380 c067ad20 c4310000 00000000 c44cc810 c27f8718 c44cc854 c067adb8 1e00: c4933000 00000002 00000001 00000000 00000000 c2130850 00000000 c2130854 1e20: c25fc488 00000000 c0ff162c 00000000 00000001 00000002 00000000 00000000 1e40: c43102c0 c43102c0 00000000 0347d2a8 c44cc810 c44cc814 c2133da8 c06d1a60 1e60: 00000000 00000000 00079028 c2012f24 fee1dead c4933000 00000058 c01431e4 1e80: 01234567 c0143a20 00000000 00000000 00000000 00000000 00000000 00000000 1ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1ec0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1ee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f80: 00000000 00000000 00000000 0347d2a8 00000002 00000004 00000078 00000058 1fa0: c010028c c0100060 00000002 00000004 fee1dead 28121969 01234567 00079028 1fc0: 00000002 00000004 00000078 00000058 0002fdc5 00000000 00000000 00090acc 1fe0: 00000058 becc9c64 b6e97e05 b6e0e5f6 600e0030 fee1dead 00000000 00000000 msm_atomic_commit_tail from commit_tail+0x9c/0x188 commit_tail from drm_atomic_helper_commit+0x160/0x188 drm_atomic_helper_commit from drm_atomic_commit+0xac/0xe0 drm_atomic_commit from drm_atomic_helper_disable_all+0x1b0/0x1c0 drm_atomic_helper_disable_all from drm_atomic_helper_shutdown+0x88/0x140 drm_atomic_helper_shutdown from device_shutdown+0x16c/0x240 device_shutdown from kernel_restart+0x38/0x90 kernel_restart from __do_sys_reboot+0x ---truncated---

In the Linux kernel, the following vulnerability has been resolved: IB/IPoIB: Fix legacy IPoIB due to wrong number of queues The cited commit creates child PKEY interfaces over netlink will multiple tx and rx queues, but some devices doesn't support more than 1 tx and 1 rx queues. This causes to a crash when traffic is sent over the PKEY interface due to the parent having a single queue but the child having multiple queues. This patch fixes the number of queues to 1 for legacy IPoIB at the earliest possible point in time. BUG: kernel NULL pointer dereference, address: 000000000000036b PGD 0 P4D 0 Oops: 0000 [#1] SMP CPU: 4 PID: 209665 Comm: python3 Not tainted 6.1.0_for_upstream_min_debug_2022_12_12_17_02 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:kmem_cache_alloc+0xcb/0x450 Code: ce 7e 49 8b 50 08 49 83 78 10 00 4d 8b 28 0f 84 cb 02 00 00 4d 85 ed 0f 84 c2 02 00 00 41 8b 44 24 28 48 8d 4a 01 49 8b 3c 24 <49> 8b 5c 05 00 4c 89 e8 65 48 0f c7 0f 0f 94 c0 84 c0 74 b8 41 8b RSP: 0018:ffff88822acbbab8 EFLAGS: 00010202 RAX: 0000000000000070 RBX: ffff8881c28e3e00 RCX: 00000000064f8dae RDX: 00000000064f8dad RSI: 0000000000000a20 RDI: 0000000000030d00 RBP: 0000000000000a20 R08: ffff8882f5d30d00 R09: ffff888104032f40 R10: ffff88810fade828 R11: 736f6d6570736575 R12: ffff88810081c000 R13: 00000000000002fb R14: ffffffff817fc865 R15: 0000000000000000 FS: 00007f9324ff9700(0000) GS:ffff8882f5d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000036b CR3: 00000001125af004 CR4: 0000000000370ea0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> skb_clone+0x55/0xd0 ip6_finish_output2+0x3fe/0x690 ip6_finish_output+0xfa/0x310 ip6_send_skb+0x1e/0x60 udp_v6_send_skb+0x1e5/0x420 udpv6_sendmsg+0xb3c/0xe60 ? ip_mc_finish_output+0x180/0x180 ? __switch_to_asm+0x3a/0x60 ? __switch_to_asm+0x34/0x60 sock_sendmsg+0x33/0x40 __sys_sendto+0x103/0x160 ? _copy_to_user+0x21/0x30 ? kvm_clock_get_cycles+0xd/0x10 ? ktime_get_ts64+0x49/0xe0 __x64_sys_sendto+0x25/0x30 do_syscall_64+0x3d/0x90 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f9374f1ed14 Code: 42 41 f8 ff 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 68 41 f8 ff 48 8b RSP: 002b:00007f9324ff7bd0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f9324ff7cc8 RCX: 00007f9374f1ed14 RDX: 00000000000002fb RSI: 00007f93000052f0 RDI: 0000000000000030 RBP: 0000000000000000 R08: 00007f9324ff7d40 R09: 000000000000001c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 000000012a05f200 R14: 0000000000000001 R15: 00007f9374d57bdc </TASK>

A NULL pointer dereference flaw was found in the Linux kernel's BPF subsystem in the way a user triggers the map_get_next_key function of the BPF bloom filter. This flaw allows a local user to crash the system. This flaw affects Linux kernel versions prior to 5.17-rc1.

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix tc flower deletion for VLAN priority Rx steering To replicate the issue:- 1) Add 1 flower filter for VLAN Priority based frame steering:- $ IFDEVNAME=eth0 $ tc qdisc add dev $IFDEVNAME ingress $ tc qdisc add dev $IFDEVNAME root mqprio num_tc 8 \ map 0 1 2 3 4 5 6 7 0 0 0 0 0 0 0 0 \ queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 hw 0 $ tc filter add dev $IFDEVNAME parent ffff: protocol 802.1Q \ flower vlan_prio 0 hw_tc 0 2) Get the 'pref' id $ tc filter show dev $IFDEVNAME ingress 3) Delete a specific tc flower record (say pref 49151) $ tc filter del dev $IFDEVNAME parent ffff: pref 49151 From dmesg, we will observe kernel NULL pointer ooops [ 197.170464] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 197.171367] #PF: supervisor read access in kernel mode [ 197.171367] #PF: error_code(0x0000) - not-present page [ 197.171367] PGD 0 P4D 0 [ 197.171367] Oops: 0000 [#1] PREEMPT SMP NOPTI <snip> [ 197.171367] RIP: 0010:tc_setup_cls+0x20b/0x4a0 [stmmac] <snip> [ 197.171367] Call Trace: [ 197.171367] <TASK> [ 197.171367] ? __stmmac_disable_all_queues+0xa8/0xe0 [stmmac] [ 197.171367] stmmac_setup_tc_block_cb+0x70/0x110 [stmmac] [ 197.171367] tc_setup_cb_destroy+0xb3/0x180 [ 197.171367] fl_hw_destroy_filter+0x94/0xc0 [cls_flower] The above issue is due to previous incorrect implementation of tc_del_vlan_flow(), shown below, that uses flow_cls_offload_flow_rule() to get struct flow_rule *rule which is no longer valid for tc filter delete operation. struct flow_rule *rule = flow_cls_offload_flow_rule(cls); struct flow_dissector *dissector = rule->match.dissector; So, to ensure tc_del_vlan_flow() deletes the right VLAN cls record for earlier configured RX queue (configured by hw_tc) in tc_add_vlan_flow(), this patch introduces stmmac_rfs_entry as driver-side flow_cls_offload record for 'RX frame steering' tc flower, currently used for VLAN priority. The implementation has taken consideration for future extension to include other type RX frame steering such as EtherType based. v2: - Clean up overly extensive backtrace and rewrite git message to better explain the kernel NULL pointer issue.

In the Linux kernel, the following vulnerability has been resolved: serial: rp2: use 'request_firmware' instead of 'request_firmware_nowait' In 'rp2_probe', the driver registers 'rp2_uart_interrupt' then calls 'rp2_fw_cb' through 'request_firmware_nowait'. In 'rp2_fw_cb', if the firmware don't exists, function just return without initializing ports of 'rp2_card'. But now the interrupt handler function has been registered, and when an interrupt comes, 'rp2_uart_interrupt' may access those ports then causing NULL pointer dereference or other bugs. Because the driver does some initialization work in 'rp2_fw_cb', in order to make the driver ready to handle interrupts, 'request_firmware' should be used instead of asynchronous 'request_firmware_nowait'. This report reveals it: INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.19.177-gdba4159c14ef-dirty #45 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59- gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xec/0x156 lib/dump_stack.c:118 assign_lock_key kernel/locking/lockdep.c:727 [inline] register_lock_class+0x14e5/0x1ba0 kernel/locking/lockdep.c:753 __lock_acquire+0x187/0x3750 kernel/locking/lockdep.c:3303 lock_acquire+0x124/0x340 kernel/locking/lockdep.c:3907 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x32/0x50 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] rp2_ch_interrupt drivers/tty/serial/rp2.c:466 [inline] rp2_asic_interrupt.isra.9+0x15d/0x990 drivers/tty/serial/rp2.c:493 rp2_uart_interrupt+0x49/0xe0 drivers/tty/serial/rp2.c:504 __handle_irq_event_percpu+0xfb/0x770 kernel/irq/handle.c:149 handle_irq_event_percpu+0x79/0x150 kernel/irq/handle.c:189 handle_irq_event+0xac/0x140 kernel/irq/handle.c:206 handle_fasteoi_irq+0x232/0x5c0 kernel/irq/chip.c:725 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline] handle_irq+0x230/0x3a0 arch/x86/kernel/irq_64.c:87 do_IRQ+0xa7/0x1e0 arch/x86/kernel/irq.c:247 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:670 </IRQ> RIP: 0010:native_safe_halt+0x28/0x30 arch/x86/include/asm/irqflags.h:61 Code: 00 00 55 be 04 00 00 00 48 c7 c7 00 c2 2f 8c 48 89 e5 e8 fb 31 e7 f8 8b 05 75 af 8d 03 85 c0 7e 07 0f 00 2d 8a 61 65 00 fb f4 <5d> c3 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 RSP: 0018:ffff88806b71fcc8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffde RAX: 0000000000000000 RBX: ffffffff8bde7e48 RCX: ffffffff88a21285 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8c2fc200 RBP: ffff88806b71fcc8 R08: fffffbfff185f840 R09: fffffbfff185f840 R10: 0000000000000001 R11: fffffbfff185f840 R12: 0000000000000002 R13: ffffffff8bea18a0 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x6f/0x360 arch/x86/kernel/process.c:557 arch_cpu_idle+0xf/0x20 arch/x86/kernel/process.c:548 default_idle_call+0x3b/0x60 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x2ab/0x3c0 kernel/sched/idle.c:263 cpu_startup_entry+0xcb/0xe0 kernel/sched/idle.c:369 start_secondary+0x3b8/0x4e0 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 PGD 8000000056d27067 P4D 8000000056d27067 PUD 56d28067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.19.177-gdba4159c14ef-dirty #45 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59- gc9ba5276e321-prebuilt.qemu.org 04/01/2014 RIP: 0010:readl arch/x86/include/asm/io.h:59 [inline] RIP: 0010:rp2_ch_interrupt drivers/tty/serial/rp2.c:472 [inline] RIP: 0010:rp2_asic_interrupt.isra.9+0x181/0x990 drivers/tty/serial/rp2.c: 493 Co ---truncated---

In the Linux kernel, the following vulnerability has been resolved: NFSv4: Fix a NULL pointer dereference in pnfs_mark_matching_lsegs_return() Commit de144ff4234f changes _pnfs_return_layout() to call pnfs_mark_matching_lsegs_return() passing NULL as the struct pnfs_layout_range argument. Unfortunately, pnfs_mark_matching_lsegs_return() doesn't check if we have a value here before dereferencing it, causing an oops. I'm able to hit this crash consistently when running connectathon basic tests on NFS v4.1/v4.2 against Ontap.

In the Linux kernel, the following vulnerability has been resolved: RDMA/ipoib: Fix warning caused by destroying non-initial netns After the commit 5ce2dced8e95 ("RDMA/ipoib: Set rtnl_link_ops for ipoib interfaces"), if the IPoIB device is moved to non-initial netns, destroying that netns lets the device vanish instead of moving it back to the initial netns, This is happening because default_device_exit() skips the interfaces due to having rtnl_link_ops set. Steps to reporoduce: ip netns add foo ip link set mlx5_ib0 netns foo ip netns delete foo WARNING: CPU: 1 PID: 704 at net/core/dev.c:11435 netdev_exit+0x3f/0x50 Modules linked in: xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink tun d fuse CPU: 1 PID: 704 Comm: kworker/u64:3 Tainted: G S W 5.13.0-rc1+ #1 Hardware name: Dell Inc. PowerEdge R630/02C2CP, BIOS 2.1.5 04/11/2016 Workqueue: netns cleanup_net RIP: 0010:netdev_exit+0x3f/0x50 Code: 48 8b bb 30 01 00 00 e8 ef 81 b1 ff 48 81 fb c0 3a 54 a1 74 13 48 8b 83 90 00 00 00 48 81 c3 90 00 00 00 48 39 d8 75 02 5b c3 <0f> 0b 5b c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 1f 44 00 RSP: 0018:ffffb297079d7e08 EFLAGS: 00010206 RAX: ffff8eb542c00040 RBX: ffff8eb541333150 RCX: 000000008010000d RDX: 000000008010000e RSI: 000000008010000d RDI: ffff8eb440042c00 RBP: ffffb297079d7e48 R08: 0000000000000001 R09: ffffffff9fdeac00 R10: ffff8eb5003be000 R11: 0000000000000001 R12: ffffffffa1545620 R13: ffffffffa1545628 R14: 0000000000000000 R15: ffffffffa1543b20 FS: 0000000000000000(0000) GS:ffff8ed37fa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005601b5f4c2e8 CR3: 0000001fc8c10002 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ops_exit_list.isra.9+0x36/0x70 cleanup_net+0x234/0x390 process_one_work+0x1cb/0x360 ? process_one_work+0x360/0x360 worker_thread+0x30/0x370 ? process_one_work+0x360/0x360 kthread+0x116/0x130 ? kthread_park+0x80/0x80 ret_from_fork+0x22/0x30 To avoid the above warning and later on the kernel panic that could happen on shutdown due to a NULL pointer dereference, make sure to set the netns_refund flag that was introduced by commit 3a5ca857079e ("can: dev: Move device back to init netns on owning netns delete") to properly restore the IPoIB interfaces to the initial netns.

In the Linux kernel, the following vulnerability has been resolved: scsi: core: Fix bad pointer dereference when ehandler kthread is invalid Commit 66a834d09293 ("scsi: core: Fix error handling of scsi_host_alloc()") changed the allocation logic to call put_device() to perform host cleanup with the assumption that IDA removal and stopping the kthread would properly be performed in scsi_host_dev_release(). However, in the unlikely case that the error handler thread fails to spawn, shost->ehandler is set to ERR_PTR(-ENOMEM). The error handler cleanup code in scsi_host_dev_release() will call kthread_stop() if shost->ehandler != NULL which will always be the case whether the kthread was successfully spawned or not. In the case that it failed to spawn this has the nasty side effect of trying to dereference an invalid pointer when kthread_stop() is called. The following splat provides an example of this behavior in the wild: scsi host11: error handler thread failed to spawn, error = -4 Kernel attempted to read user page (10c) - exploit attempt? (uid: 0) BUG: Kernel NULL pointer dereference on read at 0x0000010c Faulting instruction address: 0xc00000000818e9a8 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: ibmvscsi(+) scsi_transport_srp dm_multipath dm_mirror dm_region hash dm_log dm_mod fuse overlay squashfs loop CPU: 12 PID: 274 Comm: systemd-udevd Not tainted 5.13.0-rc7 #1 NIP: c00000000818e9a8 LR: c0000000089846e8 CTR: 0000000000007ee8 REGS: c000000037d12ea0 TRAP: 0300 Not tainted (5.13.0-rc7) MSR: 800000000280b033 &lt;SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE&gt; CR: 28228228 XER: 20040001 CFAR: c0000000089846e4 DAR: 000000000000010c DSISR: 40000000 IRQMASK: 0 GPR00: c0000000089846e8 c000000037d13140 c000000009cc1100 fffffffffffffffc GPR04: 0000000000000001 0000000000000000 0000000000000000 c000000037dc0000 GPR08: 0000000000000000 c000000037dc0000 0000000000000001 00000000fffff7ff GPR12: 0000000000008000 c00000000a049000 c000000037d13d00 000000011134d5a0 GPR16: 0000000000001740 c0080000190d0000 c0080000190d1740 c000000009129288 GPR20: c000000037d13bc0 0000000000000001 c000000037d13bc0 c0080000190b7898 GPR24: c0080000190b7708 0000000000000000 c000000033bb2c48 0000000000000000 GPR28: c000000046b28280 0000000000000000 000000000000010c fffffffffffffffc NIP [c00000000818e9a8] kthread_stop+0x38/0x230 LR [c0000000089846e8] scsi_host_dev_release+0x98/0x160 Call Trace: [c000000033bb2c48] 0xc000000033bb2c48 (unreliable) [c0000000089846e8] scsi_host_dev_release+0x98/0x160 [c00000000891e960] device_release+0x60/0x100 [c0000000087e55c4] kobject_release+0x84/0x210 [c00000000891ec78] put_device+0x28/0x40 [c000000008984ea4] scsi_host_alloc+0x314/0x430 [c0080000190b38bc] ibmvscsi_probe+0x54/0xad0 [ibmvscsi] [c000000008110104] vio_bus_probe+0xa4/0x4b0 [c00000000892a860] really_probe+0x140/0x680 [c00000000892aefc] driver_probe_device+0x15c/0x200 [c00000000892b63c] device_driver_attach+0xcc/0xe0 [c00000000892b740] __driver_attach+0xf0/0x200 [c000000008926f28] bus_for_each_dev+0xa8/0x130 [c000000008929ce4] driver_attach+0x34/0x50 [c000000008928fc0] bus_add_driver+0x1b0/0x300 [c00000000892c798] driver_register+0x98/0x1a0 [c00000000810eb60] __vio_register_driver+0x80/0xe0 [c0080000190b4a30] ibmvscsi_module_init+0x9c/0xdc [ibmvscsi] [c0000000080121d0] do_one_initcall+0x60/0x2d0 [c000000008261abc] do_init_module+0x7c/0x320 [c000000008265700] load_module+0x2350/0x25b0 [c000000008265cb4] __do_sys_finit_module+0xd4/0x160 [c000000008031110] system_call_exception+0x150/0x2d0 [c00000000800d35c] system_call_common+0xec/0x278 Fix this be nulling shost->ehandler when the kthread fails to spawn.

In the Linux kernel, the following vulnerability has been resolved: udf: Fix NULL pointer dereference in udf_symlink function In function udf_symlink, epos.bh is assigned with the value returned by udf_tgetblk. The function udf_tgetblk is defined in udf/misc.c and returns the value of sb_getblk function that could be NULL. Then, epos.bh is used without any check, causing a possible NULL pointer dereference when sb_getblk fails. This fix adds a check to validate the value of epos.bh.

In the Linux kernel, the following vulnerability has been resolved: mm/secretmem: fix NULL page->mapping dereference in page_is_secretmem() Check for a NULL page->mapping before dereferencing the mapping in page_is_secretmem(), as the page's mapping can be nullified while gup() is running, e.g. by reclaim or truncation. BUG: kernel NULL pointer dereference, address: 0000000000000068 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 6 PID: 4173897 Comm: CPU 3/KVM Tainted: G W RIP: 0010:internal_get_user_pages_fast+0x621/0x9d0 Code: <48> 81 7a 68 80 08 04 bc 0f 85 21 ff ff 8 89 c7 be RSP: 0018:ffffaa90087679b0 EFLAGS: 00010046 RAX: ffffe3f37905b900 RBX: 00007f2dd561e000 RCX: ffffe3f37905b934 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffe3f37905b900 ... CR2: 0000000000000068 CR3: 00000004c5898003 CR4: 00000000001726e0 Call Trace: get_user_pages_fast_only+0x13/0x20 hva_to_pfn+0xa9/0x3e0 try_async_pf+0xa1/0x270 direct_page_fault+0x113/0xad0 kvm_mmu_page_fault+0x69/0x680 vmx_handle_exit+0xe1/0x5d0 kvm_arch_vcpu_ioctl_run+0xd81/0x1c70 kvm_vcpu_ioctl+0x267/0x670 __x64_sys_ioctl+0x83/0xa0 do_syscall_64+0x56/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae

In the Linux kernel, the following vulnerability has been resolved: net: nexthop: fix null pointer dereference when IPv6 is not enabled When we try to add an IPv6 nexthop and IPv6 is not enabled (!CONFIG_IPV6) we'll hit a NULL pointer dereference[1] in the error path of nh_create_ipv6() due to calling ipv6_stub->fib6_nh_release. The bug has been present since the beginning of IPv6 nexthop gateway support. Commit 1aefd3de7bc6 ("ipv6: Add fib6_nh_init and release to stubs") tells us that only fib6_nh_init has a dummy stub because fib6_nh_release should not be called if fib6_nh_init returns an error, but the commit below added a call to ipv6_stub->fib6_nh_release in its error path. To fix it return the dummy stub's -EAFNOSUPPORT error directly without calling ipv6_stub->fib6_nh_release in nh_create_ipv6()'s error path. [1] Output is a bit truncated, but it clearly shows the error. BUG: kernel NULL pointer dereference, address: 000000000000000000 #PF: supervisor instruction fetch in kernel modede #PF: error_code(0x0010) - not-present pagege PGD 0 P4D 0 Oops: 0010 [#1] PREEMPT SMP NOPTI CPU: 4 PID: 638 Comm: ip Kdump: loaded Not tainted 5.16.0-rc1+ #446 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014 RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffff888109f5b8f0 EFLAGS: 00010286^Ac RAX: 0000000000000000 RBX: ffff888109f5ba28 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881008a2860 RBP: ffff888109f5b9d8 R08: 0000000000000000 R09: 0000000000000000 R10: ffff888109f5b978 R11: ffff888109f5b948 R12: 00000000ffffff9f R13: ffff8881008a2a80 R14: ffff8881008a2860 R15: ffff8881008a2840 FS: 00007f98de70f100(0000) GS:ffff88822bf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000100efc000 CR4: 00000000000006e0 Call Trace: <TASK> nh_create_ipv6+0xed/0x10c rtm_new_nexthop+0x6d7/0x13f3 ? check_preemption_disabled+0x3d/0xf2 ? lock_is_held_type+0xbe/0xfd rtnetlink_rcv_msg+0x23f/0x26a ? check_preemption_disabled+0x3d/0xf2 ? rtnl_calcit.isra.0+0x147/0x147 netlink_rcv_skb+0x61/0xb2 netlink_unicast+0x100/0x187 netlink_sendmsg+0x37f/0x3a0 ? netlink_unicast+0x187/0x187 sock_sendmsg_nosec+0x67/0x9b ____sys_sendmsg+0x19d/0x1f9 ? copy_msghdr_from_user+0x4c/0x5e ? rcu_read_lock_any_held+0x2a/0x78 ___sys_sendmsg+0x6c/0x8c ? asm_sysvec_apic_timer_interrupt+0x12/0x20 ? lockdep_hardirqs_on+0xd9/0x102 ? sockfd_lookup_light+0x69/0x99 __sys_sendmsg+0x50/0x6e do_syscall_64+0xcb/0xf2 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f98dea28914 Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b5 0f 1f 80 00 00 00 00 48 8d 05 e9 5d 0c 00 8b 00 85 c0 75 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 41 54 41 89 d4 55 48 89 f5 53 RSP: 002b:00007fff859f5e68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e2e RAX: ffffffffffffffda RBX: 00000000619cb810 RCX: 00007f98dea28914 RDX: 0000000000000000 RSI: 00007fff859f5ed0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000008 R10: fffffffffffffce6 R11: 0000000000000246 R12: 0000000000000001 R13: 000055c0097ae520 R14: 000055c0097957fd R15: 00007fff859f63a0 </TASK> Modules linked in: bridge stp llc bonding virtio_net

In the Linux kernel, the following vulnerability has been resolved: nfc: fix segfault in nfc_genl_dump_devices_done When kmalloc in nfc_genl_dump_devices() fails then nfc_genl_dump_devices_done() segfaults as below KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 25 Comm: kworker/0:1 Not tainted 5.16.0-rc4-01180-g2a987e65025e-dirty #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-6.fc35 04/01/2014 Workqueue: events netlink_sock_destruct_work RIP: 0010:klist_iter_exit+0x26/0x80 Call Trace: <TASK> class_dev_iter_exit+0x15/0x20 nfc_genl_dump_devices_done+0x3b/0x50 genl_lock_done+0x84/0xd0 netlink_sock_destruct+0x8f/0x270 __sk_destruct+0x64/0x3b0 sk_destruct+0xa8/0xd0 __sk_free+0x2e8/0x3d0 sk_free+0x51/0x90 netlink_sock_destruct_work+0x1c/0x20 process_one_work+0x411/0x710 worker_thread+0x6fd/0xa80

In the Linux kernel, the following vulnerability has been resolved: can: mcp251x: fix resume from sleep before interface was brought up Since 8ce8c0abcba3 the driver queues work via priv->restart_work when resuming after suspend, even when the interface was not previously enabled. This causes a null dereference error as the workqueue is only allocated and initialized in mcp251x_open(). To fix this we move the workqueue init to mcp251x_can_probe() as there is no reason to do it later and repeat it whenever mcp251x_open() is called. [mkl: fix error handling in mcp251x_stop()]

In the Linux kernel, the following vulnerability has been resolved: i40e: Fix NULL ptr dereference on VSI filter sync Remove the reason of null pointer dereference in sync VSI filters. Added new I40E_VSI_RELEASING flag to signalize deleting and releasing of VSI resources to sync this thread with sync filters subtask. Without this patch it is possible to start update the VSI filter list after VSI is removed, that's causing a kernel oops.

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Make sure GHCB is mapped before updating Access to the GHCB is mainly in the VMGEXIT path and it is known that the GHCB will be mapped. But there are two paths where it is possible the GHCB might not be mapped. The sev_vcpu_deliver_sipi_vector() routine will update the GHCB to inform the caller of the AP Reset Hold NAE event that a SIPI has been delivered. However, if a SIPI is performed without a corresponding AP Reset Hold, then the GHCB might not be mapped (depending on the previous VMEXIT), which will result in a NULL pointer dereference. The svm_complete_emulated_msr() routine will update the GHCB to inform the caller of a RDMSR/WRMSR operation about any errors. While it is likely that the GHCB will be mapped in this situation, add a safe guard in this path to be certain a NULL pointer dereference is not encountered.

In the Linux kernel, the following vulnerability has been resolved: sfc: farch: fix TX queue lookup in TX flush done handling We're starting from a TXQ instance number ('qid'), not a TXQ type, so efx_get_tx_queue() is inappropriate (and could return NULL, leading to panics).

In the Linux kernel, the following vulnerability has been resolved: selinux: fix NULL-pointer dereference when hashtab allocation fails When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails.

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: ep0: fix NULL pointer exception There is no validation of the index from dwc3_wIndex_to_dep() and we might be referring a non-existing ep and trigger a NULL pointer exception. In certain configurations we might use fewer eps and the index might wrongly indicate a larger ep index than existing. By adding this validation from the patch we can actually report a wrong index back to the caller. In our usecase we are using a composite device on an older kernel, but upstream might use this fix also. Unfortunately, I cannot describe the hardware for others to reproduce the issue as it is a proprietary implementation. [ 82.958261] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a4 [ 82.966891] Mem abort info: [ 82.969663] ESR = 0x96000006 [ 82.972703] Exception class = DABT (current EL), IL = 32 bits [ 82.978603] SET = 0, FnV = 0 [ 82.981642] EA = 0, S1PTW = 0 [ 82.984765] Data abort info: [ 82.987631] ISV = 0, ISS = 0x00000006 [ 82.991449] CM = 0, WnR = 0 [ 82.994409] user pgtable: 4k pages, 39-bit VAs, pgdp = 00000000c6210ccc [ 83.000999] [00000000000000a4] pgd=0000000053aa5003, pud=0000000053aa5003, pmd=0000000000000000 [ 83.009685] Internal error: Oops: 96000006 [#1] PREEMPT SMP [ 83.026433] Process irq/62-dwc3 (pid: 303, stack limit = 0x000000003985154c) [ 83.033470] CPU: 0 PID: 303 Comm: irq/62-dwc3 Not tainted 4.19.124 #1 [ 83.044836] pstate: 60000085 (nZCv daIf -PAN -UAO) [ 83.049628] pc : dwc3_ep0_handle_feature+0x414/0x43c [ 83.054558] lr : dwc3_ep0_interrupt+0x3b4/0xc94 ... [ 83.141788] Call trace: [ 83.144227] dwc3_ep0_handle_feature+0x414/0x43c [ 83.148823] dwc3_ep0_interrupt+0x3b4/0xc94 [ 83.181546] ---[ end trace aac6b5267d84c32f ]---

In the Linux kernel, the following vulnerability has been resolved: serial: liteuart: Fix NULL pointer dereference in ->remove() drvdata has to be set in _probe() - otherwise platform_get_drvdata() causes null pointer dereference BUG in _remove().

In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix vlan tunnel dst null pointer dereference This patch fixes a tunnel_dst null pointer dereference due to lockless access in the tunnel egress path. When deleting a vlan tunnel the tunnel_dst pointer is set to NULL without waiting a grace period (i.e. while it's still usable) and packets egressing are dereferencing it without checking. Use READ/WRITE_ONCE to annotate the lockless use of tunnel_id, use RCU for accessing tunnel_dst and make sure it is read only once and checked in the egress path. The dst is already properly RCU protected so we don't need to do anything fancy than to make sure tunnel_id and tunnel_dst are read only once and checked in the egress path.

In the Linux kernel, the following vulnerability has been resolved: media: staging: media: zoran: calculate the right buffer number for zoran_reap_stat_com On the case tmp_dcim=1, the index of buffer is miscalculated. This generate a NULL pointer dereference later. So let's fix the calcul and add a check to prevent this to reappear.

In the Linux kernel, the following vulnerability has been resolved: ARM: davinci: da850-evm: Avoid NULL pointer dereference With newer versions of GCC, there is a panic in da850_evm_config_emac() when booting multi_v5_defconfig in QEMU under the palmetto-bmc machine: Unable to handle kernel NULL pointer dereference at virtual address 00000020 pgd = (ptrval) [00000020] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.15.0 #1 Hardware name: Generic DT based system PC is at da850_evm_config_emac+0x1c/0x120 LR is at do_one_initcall+0x50/0x1e0 The emac_pdata pointer in soc_info is NULL because davinci_soc_info only gets populated on davinci machines but da850_evm_config_emac() is called on all machines via device_initcall(). Move the rmii_en assignment below the machine check so that it is only dereferenced when running on a supported SoC.

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: usx2y: Don't call free_pages_exact() with NULL address Unlike some other functions, we can't pass NULL pointer to free_pages_exact(). Add a proper NULL check for avoiding possible Oops.

In the Linux kernel, the following vulnerability has been resolved: octeontx2-af: Fix possible null pointer dereference. This patch fixes possible null pointer dereference in files "rvu_debugfs.c" and "rvu_nix.c"

In the Linux kernel, the following vulnerability has been resolved: drm: mxsfb: Fix NULL pointer dereference crash on unload The mxsfb->crtc.funcs may already be NULL when unloading the driver, in which case calling mxsfb_irq_disable() via drm_irq_uninstall() from mxsfb_unload() leads to NULL pointer dereference. Since all we care about is masking the IRQ and mxsfb->base is still valid, just use that to clear and mask the IRQ.

In the Linux kernel, the following vulnerability has been resolved: usb: common: usb-conn-gpio: fix NULL pointer dereference of charger When power on system with OTG cable, IDDIG's interrupt arises before the charger registration, it will cause a NULL pointer dereference, fix the issue by registering the power supply before requesting IDDIG/VBUS irq.

In the Linux kernel, the following vulnerability has been resolved: gve: Add NULL pointer checks when freeing irqs. When freeing notification blocks, we index priv->msix_vectors. If we failed to allocate priv->msix_vectors (see abort_with_msix_vectors) this could lead to a NULL pointer dereference if the driver is unloaded.

In the Linux kernel, the following vulnerability has been resolved: usb: host: ohci-tmio: 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: 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: nfsd: fix NULL dereference in nfs3svc_encode_getaclres In error cases the dentry may be NULL. Before 20798dfe249a, the encoder also checked dentry and d_really_is_positive(dentry), but that looks like overkill to me--zero status should be enough to guarantee a positive dentry. This isn't the first time we've seen an error-case NULL dereference hidden in the initialization of a local variable in an xdr encoder. But I went back through the other recent rewrites and didn't spot any similar bugs.

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Fix null pointer dereference in svc_rqst_free() When alloc_pages_node() returns null in svc_rqst_alloc(), the null rq_scratch_page pointer will be dereferenced when calling put_page() in svc_rqst_free(). Fix it by adding a null check. Addresses-Coverity: ("Dereference after null check")

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: scsi: qedf: Add pointer checks in qedf_update_link_speed() The following trace was observed: [ 14.042059] Call Trace: [ 14.042061] <IRQ> [ 14.042068] qedf_link_update+0x144/0x1f0 [qedf] [ 14.042117] qed_link_update+0x5c/0x80 [qed] [ 14.042135] qed_mcp_handle_link_change+0x2d2/0x410 [qed] [ 14.042155] ? qed_set_ptt+0x70/0x80 [qed] [ 14.042170] ? qed_set_ptt+0x70/0x80 [qed] [ 14.042186] ? qed_rd+0x13/0x40 [qed] [ 14.042205] qed_mcp_handle_events+0x437/0x690 [qed] [ 14.042221] ? qed_set_ptt+0x70/0x80 [qed] [ 14.042239] qed_int_sp_dpc+0x3a6/0x3e0 [qed] [ 14.042245] tasklet_action_common.isra.14+0x5a/0x100 [ 14.042250] __do_softirq+0xe4/0x2f8 [ 14.042253] irq_exit+0xf7/0x100 [ 14.042255] do_IRQ+0x7f/0xd0 [ 14.042257] common_interrupt+0xf/0xf [ 14.042259] </IRQ> API qedf_link_update() is getting called from QED but by that time shost_data is not initialised. This results in a NULL pointer dereference when we try to dereference shost_data while updating supported_speeds. Add a NULL pointer check before dereferencing shost_data.

In the Linux kernel, the following vulnerability has been resolved: ASoC: core: Fix Null-point-dereference in fmt_single_name() Check the return value of devm_kstrdup() in case of Null-point-dereference.

In the Linux kernel, the following vulnerability has been resolved: sfc: farch: fix TX queue lookup in TX event handling We're starting from a TXQ label, not a TXQ type, so efx_channel_get_tx_queue() is inappropriate (and could return NULL, leading to panics).

In the Linux kernel, the following vulnerability has been resolved: i40e: Fix NULL pointer dereference in i40e_dbg_dump_desc When trying to dump VFs VSI RX/TX descriptors using debugfs there was a crash due to NULL pointer dereference in i40e_dbg_dump_desc. Added a check to i40e_dbg_dump_desc that checks if VSI type is correct for dumping RX/TX descriptors.

In the Linux kernel, the following vulnerability has been resolved: efi/fdt: fix panic when no valid fdt found setup_arch() would invoke efi_init()->efi_get_fdt_params(). If no valid fdt found then initial_boot_params will be null. So we should stop further fdt processing here. I encountered this issue on risc-v.

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: fix null pointer dereference on pointer cs_desc The pointer cs_desc return from snd_usb_find_clock_source 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: dwc2: 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: ACPI: fix NULL pointer dereference Commit 71f642833284 ("ACPI: utils: Fix reference counting in for_each_acpi_dev_match()") started doing "acpi_dev_put()" on a pointer that was possibly NULL. That fails miserably, because that helper inline function is not set up to handle that case. Just make acpi_dev_put() silently accept a NULL pointer, rather than calling down to put_device() with an invalid offset off that NULL pointer.

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---