Search Results (19225 CVEs found)

CVE Vendors Products Updated CVSS v3.1
CVE-2025-68323 1 Linux 1 Linux Kernel 2026-04-15 N/A
In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: fix use-after-free caused by uec->work The delayed work uec->work is scheduled in gaokun_ucsi_probe() but never properly canceled in gaokun_ucsi_remove(). This creates use-after-free scenarios where the ucsi and gaokun_ucsi structure are freed after ucsi_destroy() completes execution, while the gaokun_ucsi_register_worker() might be either currently executing or still pending in the work queue. The already-freed gaokun_ucsi or ucsi structure may then be accessed. Furthermore, the race window is 3 seconds, which is sufficiently long to make this bug easily reproducible. The following is the trace captured by KASAN: ================================================================== BUG: KASAN: slab-use-after-free in __run_timers+0x5ec/0x630 Write of size 8 at addr ffff00000ec28cc8 by task swapper/0/0 ... Call trace: show_stack+0x18/0x24 (C) dump_stack_lvl+0x78/0x90 print_report+0x114/0x580 kasan_report+0xa4/0xf0 __asan_report_store8_noabort+0x20/0x2c __run_timers+0x5ec/0x630 run_timer_softirq+0xe8/0x1cc handle_softirqs+0x294/0x720 __do_softirq+0x14/0x20 ____do_softirq+0x10/0x1c call_on_irq_stack+0x30/0x48 do_softirq_own_stack+0x1c/0x28 __irq_exit_rcu+0x27c/0x364 irq_exit_rcu+0x10/0x1c el1_interrupt+0x40/0x60 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x6c/0x70 arch_local_irq_enable+0x4/0x8 (P) do_idle+0x334/0x458 cpu_startup_entry+0x60/0x70 rest_init+0x158/0x174 start_kernel+0x2f8/0x394 __primary_switched+0x8c/0x94 Allocated by task 72 on cpu 0 at 27.510341s: kasan_save_stack+0x2c/0x54 kasan_save_track+0x24/0x5c kasan_save_alloc_info+0x40/0x54 __kasan_kmalloc+0xa0/0xb8 __kmalloc_node_track_caller_noprof+0x1c0/0x588 devm_kmalloc+0x7c/0x1c8 gaokun_ucsi_probe+0xa0/0x840 auxiliary_bus_probe+0x94/0xf8 really_probe+0x17c/0x5b8 __driver_probe_device+0x158/0x2c4 driver_probe_device+0x10c/0x264 __device_attach_driver+0x168/0x2d0 bus_for_each_drv+0x100/0x188 __device_attach+0x174/0x368 device_initial_probe+0x14/0x20 bus_probe_device+0x120/0x150 device_add+0xb3c/0x10fc __auxiliary_device_add+0x88/0x130 ... Freed by task 73 on cpu 1 at 28.910627s: kasan_save_stack+0x2c/0x54 kasan_save_track+0x24/0x5c __kasan_save_free_info+0x4c/0x74 __kasan_slab_free+0x60/0x8c kfree+0xd4/0x410 devres_release_all+0x140/0x1f0 device_unbind_cleanup+0x20/0x190 device_release_driver_internal+0x344/0x460 device_release_driver+0x18/0x24 bus_remove_device+0x198/0x274 device_del+0x310/0xa84 ... The buggy address belongs to the object at ffff00000ec28c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 200 bytes inside of freed 512-byte region The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4ec28 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x3fffe0000000040(head|node=0|zone=0|lastcpupid=0x1ffff) page_type: f5(slab) raw: 03fffe0000000040 ffff000008801c80 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 03fffe0000000040 ffff000008801c80 dead000000000122 0000000000000000 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 03fffe0000000002 fffffdffc03b0a01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff00000ec28b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff00000ec28c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff00000ec28c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff00000ec28d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff00000ec28d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================ ---truncated---
CVE-2025-40289 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: hide VRAM sysfs attributes on GPUs without VRAM Otherwise accessing them can cause a crash.
CVE-2025-40286 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: smb/server: fix possible memory leak in smb2_read() Memory leak occurs when ksmbd_vfs_read() fails. Fix this by adding the missing kvfree().
CVE-2025-40285 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: smb/server: fix possible refcount leak in smb2_sess_setup() Reference count of ksmbd_session will leak when session need reconnect. Fix this by adding the missing ksmbd_user_session_put().
CVE-2025-40284 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: cancel mesh send timer when hdev removed mesh_send_done timer is not canceled when hdev is removed, which causes crash if the timer triggers after hdev is gone. Cancel the timer when MGMT removes the hdev, like other MGMT timers. Should fix the BUG: sporadically seen by BlueZ test bot (in "Mesh - Send cancel - 1" test). Log: ------ BUG: KASAN: slab-use-after-free in run_timer_softirq+0x76b/0x7d0 ... Freed by task 36: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 __kasan_save_free_info+0x3a/0x60 __kasan_slab_free+0x43/0x70 kfree+0x103/0x500 device_release+0x9a/0x210 kobject_put+0x100/0x1e0 vhci_release+0x18b/0x240 ------
CVE-2022-50661 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: seccomp: Move copy_seccomp() to no failure path. Our syzbot instance reported memory leaks in do_seccomp() [0], similar to the report [1]. It shows that we miss freeing struct seccomp_filter and some objects included in it. We can reproduce the issue with the program below [2] which calls one seccomp() and two clone() syscalls. The first clone()d child exits earlier than its parent and sends a signal to kill it during the second clone(), more precisely before the fatal_signal_pending() test in copy_process(). When the parent receives the signal, it has to destroy the embryonic process and return -EINTR to user space. In the failure path, we have to call seccomp_filter_release() to decrement the filter's refcount. Initially, we called it in free_task() called from the failure path, but the commit 3a15fb6ed92c ("seccomp: release filter after task is fully dead") moved it to release_task() to notify user space as early as possible that the filter is no longer used. To keep the change and current seccomp refcount semantics, let's move copy_seccomp() just after the signal check and add a WARN_ON_ONCE() in free_task() for future debugging. [0]: unreferenced object 0xffff8880063add00 (size 256): comm "repro_seccomp", pid 230, jiffies 4294687090 (age 9.914s) hex dump (first 32 bytes): 01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................ ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................ backtrace: do_seccomp (./include/linux/slab.h:600 ./include/linux/slab.h:733 kernel/seccomp.c:666 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) unreferenced object 0xffffc90000035000 (size 4096): comm "repro_seccomp", pid 230, jiffies 4294687090 (age 9.915s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 05 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: __vmalloc_node_range (mm/vmalloc.c:3226) __vmalloc_node (mm/vmalloc.c:3261 (discriminator 4)) bpf_prog_alloc_no_stats (kernel/bpf/core.c:91) bpf_prog_alloc (kernel/bpf/core.c:129) bpf_prog_create_from_user (net/core/filter.c:1414) do_seccomp (kernel/seccomp.c:671 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) unreferenced object 0xffff888003fa1000 (size 1024): comm "repro_seccomp", pid 230, jiffies 4294687090 (age 9.915s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: bpf_prog_alloc_no_stats (./include/linux/slab.h:600 ./include/linux/slab.h:733 kernel/bpf/core.c:95) bpf_prog_alloc (kernel/bpf/core.c:129) bpf_prog_create_from_user (net/core/filter.c:1414) do_seccomp (kernel/seccomp.c:671 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) unreferenced object 0xffff888006360240 (size 16): comm "repro_seccomp", pid 230, jiffies 4294687090 (age 9.915s) hex dump (first 16 bytes): 01 00 37 00 76 65 72 6c e0 83 01 06 80 88 ff ff ..7.verl........ backtrace: bpf_prog_store_orig_filter (net/core/filter.c:1137) bpf_prog_create_from_user (net/core/filter.c:1428) do_seccomp (kernel/seccomp.c:671 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) unreferenced object 0xffff888 ---truncated---
CVE-2025-40283 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btusb: reorder cleanup in btusb_disconnect to avoid UAF There is a KASAN: slab-use-after-free read in btusb_disconnect(). Calling "usb_driver_release_interface(&btusb_driver, data->intf)" will free the btusb data associated with the interface. The same data is then used later in the function, hence the UAF. Fix by moving the accesses to btusb data to before the data is free'd.
CVE-2025-40282 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: 6lowpan: reset link-local header on ipv6 recv path Bluetooth 6lowpan.c netdev has header_ops, so it must set link-local header for RX skb, otherwise things crash, eg. with AF_PACKET SOCK_RAW Add missing skb_reset_mac_header() for uncompressed ipv6 RX path. For the compressed one, it is done in lowpan_header_decompress(). Log: (BlueZ 6lowpan-tester Client Recv Raw - Success) ------ kernel BUG at net/core/skbuff.c:212! Call Trace: <IRQ> ... packet_rcv (net/packet/af_packet.c:2152) ... <TASK> __local_bh_enable_ip (kernel/softirq.c:407) netif_rx (net/core/dev.c:5648) chan_recv_cb (net/bluetooth/6lowpan.c:294 net/bluetooth/6lowpan.c:359) ------
CVE-2025-39995 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: media: i2c: tc358743: Fix use-after-free bugs caused by orphan timer in probe The state->timer is a cyclic timer that schedules work_i2c_poll and delayed_work_enable_hotplug, while rearming itself. Using timer_delete() fails to guarantee the timer isn't still running when destroyed, similarly cancel_delayed_work() cannot ensure delayed_work_enable_hotplug has terminated if already executing. During probe failure after timer initialization, these may continue running as orphans and reference the already-freed tc358743_state object through tc358743_irq_poll_timer. The following is the trace captured by KASAN. BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0 Write of size 8 at addr ffff88800ded83c8 by task swapper/1/0 ... Call Trace: <IRQ> dump_stack_lvl+0x55/0x70 print_report+0xcf/0x610 ? __pfx_sched_balance_find_src_group+0x10/0x10 ? __run_timer_base.part.0+0x7d7/0x8c0 kasan_report+0xb8/0xf0 ? __run_timer_base.part.0+0x7d7/0x8c0 __run_timer_base.part.0+0x7d7/0x8c0 ? rcu_sched_clock_irq+0xb06/0x27d0 ? __pfx___run_timer_base.part.0+0x10/0x10 ? try_to_wake_up+0xb15/0x1960 ? tmigr_update_events+0x280/0x740 ? _raw_spin_lock_irq+0x80/0xe0 ? __pfx__raw_spin_lock_irq+0x10/0x10 tmigr_handle_remote_up+0x603/0x7e0 ? __pfx_tmigr_handle_remote_up+0x10/0x10 ? sched_balance_trigger+0x98/0x9f0 ? sched_tick+0x221/0x5a0 ? _raw_spin_lock_irq+0x80/0xe0 ? __pfx__raw_spin_lock_irq+0x10/0x10 ? tick_nohz_handler+0x339/0x440 ? __pfx_tmigr_handle_remote_up+0x10/0x10 __walk_groups.isra.0+0x42/0x150 tmigr_handle_remote+0x1f4/0x2e0 ? __pfx_tmigr_handle_remote+0x10/0x10 ? ktime_get+0x60/0x140 ? lapic_next_event+0x11/0x20 ? clockevents_program_event+0x1d4/0x2a0 ? hrtimer_interrupt+0x322/0x780 handle_softirqs+0x16a/0x550 irq_exit_rcu+0xaf/0xe0 sysvec_apic_timer_interrupt+0x70/0x80 </IRQ> ... Allocated by task 141: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x7f/0x90 __kmalloc_node_track_caller_noprof+0x198/0x430 devm_kmalloc+0x7b/0x1e0 tc358743_probe+0xb7/0x610 i2c_device_probe+0x51d/0x880 really_probe+0x1ca/0x5c0 __driver_probe_device+0x248/0x310 driver_probe_device+0x44/0x120 __device_attach_driver+0x174/0x220 bus_for_each_drv+0x100/0x190 __device_attach+0x206/0x370 bus_probe_device+0x123/0x170 device_add+0xd25/0x1470 i2c_new_client_device+0x7a0/0xcd0 do_one_initcall+0x89/0x300 do_init_module+0x29d/0x7f0 load_module+0x4f48/0x69e0 init_module_from_file+0xe4/0x150 idempotent_init_module+0x320/0x670 __x64_sys_finit_module+0xbd/0x120 do_syscall_64+0xac/0x280 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 141: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3a/0x60 __kasan_slab_free+0x3f/0x50 kfree+0x137/0x370 release_nodes+0xa4/0x100 devres_release_group+0x1b2/0x380 i2c_device_probe+0x694/0x880 really_probe+0x1ca/0x5c0 __driver_probe_device+0x248/0x310 driver_probe_device+0x44/0x120 __device_attach_driver+0x174/0x220 bus_for_each_drv+0x100/0x190 __device_attach+0x206/0x370 bus_probe_device+0x123/0x170 device_add+0xd25/0x1470 i2c_new_client_device+0x7a0/0xcd0 do_one_initcall+0x89/0x300 do_init_module+0x29d/0x7f0 load_module+0x4f48/0x69e0 init_module_from_file+0xe4/0x150 idempotent_init_module+0x320/0x670 __x64_sys_finit_module+0xbd/0x120 do_syscall_64+0xac/0x280 entry_SYSCALL_64_after_hwframe+0x77/0x7f ... Replace timer_delete() with timer_delete_sync() and cancel_delayed_work() with cancel_delayed_work_sync() to ensure proper termination of timer and work items before resource cleanup. This bug was initially identified through static analysis. For reproduction and testing, I created a functional emulation of the tc358743 device via a kernel module and introduced faults through the debugfs interface.
CVE-2025-40269 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix potential overflow of PCM transfer buffer The PCM stream data in USB-audio driver is transferred over USB URB packet buffers, and each packet size is determined dynamically. The packet sizes are limited by some factors such as wMaxPacketSize USB descriptor. OTOH, in the current code, the actually used packet sizes are determined only by the rate and the PPS, which may be bigger than the size limit above. This results in a buffer overflow, as reported by syzbot. Basically when the limit is smaller than the calculated packet size, it implies that something is wrong, most likely a weird USB descriptor. So the best option would be just to return an error at the parameter setup time before doing any further operations. This patch introduces such a sanity check, and returns -EINVAL when the packet size is greater than maxpacksize. The comparison with ep->packsize[1] alone should suffice since it's always equal or greater than ep->packsize[0].
CVE-2025-40304 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: fbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-bounds Add bounds checking to prevent writes past framebuffer boundaries when rendering text near screen edges. Return early if the Y position is off-screen and clip image height to screen boundary. Break from the rendering loop if the X position is off-screen. When clipping image width to fit the screen, update the character count to match the clipped width to prevent buffer size mismatches. Without the character count update, bit_putcs_aligned and bit_putcs_unaligned receive mismatched parameters where the buffer is allocated for the clipped width but cnt reflects the original larger count, causing out-of-bounds writes.
CVE-2022-50663 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix possible memory leak in stmmac_dvr_probe() The bitmap_free() should be called to free priv->af_xdp_zc_qps when create_singlethread_workqueue() fails, otherwise there will be a memory leak, so we add the err path error_wq_init to fix it.
CVE-2025-40267 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: io_uring/rw: ensure allocated iovec gets cleared for early failure A previous commit reused the recyling infrastructure for early cleanup, but this is not enough for the case where our internal caches have overflowed. If this happens, then the allocated iovec can get leaked if the request is also aborted early. Reinstate the previous forced free of the iovec for that situation.
CVE-2022-50582 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: regulator: core: Prevent integer underflow By using a ratio of delay to poll_enabled_time that is not integer time_remaining underflows and does not exit the loop as expected. As delay could be derived from DT and poll_enabled_time is defined in the driver this can easily happen. Use a signed iterator to make sure that the loop exits once the remaining time is negative.
CVE-2022-50569 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: xfrm: Update ipcomp_scratches with NULL when freed Currently if ipcomp_alloc_scratches() fails to allocate memory ipcomp_scratches holds obsolete address. So when we try to free the percpu scratches using ipcomp_free_scratches() it tries to vfree non existent vm area. Described below: static void * __percpu *ipcomp_alloc_scratches(void) { ... scratches = alloc_percpu(void *); if (!scratches) return NULL; ipcomp_scratches does not know about this allocation failure. Therefore holding the old obsolete address. ... } So when we free, static void ipcomp_free_scratches(void) { ... scratches = ipcomp_scratches; Assigning obsolete address from ipcomp_scratches if (!scratches) return; for_each_possible_cpu(i) vfree(*per_cpu_ptr(scratches, i)); Trying to free non existent page, causing warning: trying to vfree existent vm area. ... } Fix this breakage by updating ipcomp_scrtches with NULL when scratches is freed
CVE-2025-40015 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: media: stm32-csi: Fix dereference before NULL check In 'stm32_csi_start', 'csidev->s_subdev' is dereferenced directly while assigning a value to the 'src_pad'. However the same value is being checked against NULL at a later point of time indicating that there are chances that the value can be NULL. Move the dereference after the NULL check.
CVE-2022-50664 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: media: dvb-frontends: fix leak of memory fw
CVE-2022-50567 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: fs: jfs: fix shift-out-of-bounds in dbAllocAG Syzbot found a crash : UBSAN: shift-out-of-bounds in dbAllocAG. The underlying bug is the missing check of bmp->db_agl2size. The field can be greater than 64 and trigger the shift-out-of-bounds. Fix this bug by adding a check of bmp->db_agl2size in dbMount since this field is used in many following functions. The upper bound for this field is L2MAXL2SIZE - L2MAXAG, thanks for the help of Dave Kleikamp. Note that, for maintenance, I reorganized error handling code of dbMount.
CVE-2022-50564 1 Linux 1 Linux Kernel 2026-04-15 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: s390/netiucv: Fix return type of netiucv_tx() With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals: drivers/s390/net/netiucv.c:1854:21: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] .ndo_start_xmit = netiucv_tx, ^~~~~~~~~~ ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of netiucv_tx() to match the prototype's to resolve the warning and potential CFI failure, should s390 select ARCH_SUPPORTS_CFI_CLANG in the future. Additionally, while in the area, remove a comment block that is no longer relevant.
CVE-2025-40142 1 Linux 1 Linux Kernel 2026-04-15 7.0 High
In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Disable bottom softirqs as part of spin_lock_irq() on PREEMPT_RT snd_pcm_group_lock_irq() acquires a spinlock_t and disables interrupts via spin_lock_irq(). This also implicitly disables the handling of softirqs such as TIMER_SOFTIRQ. On PREEMPT_RT softirqs are preemptible and spin_lock_irq() does not disable them. That means a timer can be invoked during spin_lock_irq() on the same CPU. Due to synchronisations reasons local_bh_disable() has a per-CPU lock named softirq_ctrl.lock which synchronizes individual softirq against each other. syz-bot managed to trigger a lockdep report where softirq_ctrl.lock is acquired in hrtimer_cancel() in addition to hrtimer_run_softirq(). This is a possible deadlock. The softirq_ctrl.lock can not be made part of spin_lock_irq() as this would lead to too much synchronisation against individual threads on the system. To avoid the possible deadlock, softirqs must be manually disabled before the lock is acquired. Disable softirqs before the lock is acquired on PREEMPT_RT.