BUG: soft lockup in file_free

Status: moderation: reported on 2026/06/16 10:58
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+108e774ad0eb9db0d8bd@syzkaller.appspotmail.com
First crash: 60d, last: 60d
▶ ▼ ✨ AI Jobs (6)
ID Workflow Result Correct Bug Created Started Finished Revision
ec713916 assessment-security 💥 BUG: soft lockup in file_free 2026/07/18 00:01 2026/07/18 00:01 2026/07/18 00:01 8aaff637
e94c58a9 assessment-security 💥 BUG: soft lockup in file_free 2026/07/01 00:09 2026/07/01 00:09 2026/07/01 00:09 93f57954
89d2ba1d assessment-security 💥 BUG: soft lockup in file_free 2026/06/23 00:02 2026/06/23 00:02 2026/06/23 00:02 5a630be6
f6c3aa53 assessment-security 💥 BUG: soft lockup in file_free 2026/06/18 04:01 2026/06/18 04:01 2026/06/18 04:01 b62b3ded
18faed48 assessment-security 💥 BUG: soft lockup in file_free 2026/06/16 00:01 2026/06/16 00:01 2026/06/16 00:01 50bb0618
6388b04e assessment-security 💥 BUG: soft lockup in file_free 2026/06/14 00:01 2026/06/14 00:01 2026/06/14 00:02 4f06757f
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in file_free (2) fs 1 1 174d 174d 0/29 auto-obsoleted due to no activity on 2026/05/19 15:58
upstream INFO: rcu detected stall in file_free fs 1 5 660d 751d 0/29 auto-obsoleted due to no activity on 2025/01/18 07:51

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [syz-executor:10668]
Modules linked in:
irq event stamp: 169424
hardirqs last  enabled at (169423): [<ffff8000867cdd20>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline]
hardirqs last  enabled at (169423): [<ffff8000867cdd20>] _raw_spin_unlock_irqrestore+0x38/0x98 kernel/locking/spinlock.c:198
hardirqs last disabled at (169424): [<ffff8000867a94b4>] __el1_irq arch/arm64/kernel/entry-common.c:506 [inline]
hardirqs last disabled at (169424): [<ffff8000867a94b4>] el1_interrupt+0x28/0x60 arch/arm64/kernel/entry-common.c:522
softirqs last  enabled at (169396): [<ffff80008030a098>] softirq_handle_end kernel/softirq.c:468 [inline]
softirqs last  enabled at (169396): [<ffff80008030a098>] handle_softirqs+0xbc4/0xd34 kernel/softirq.c:650
softirqs last disabled at (169391): [<ffff8000800204b0>] __do_softirq+0x14/0x20 kernel/softirq.c:656
CPU: 0 UID: 0 PID: 10668 Comm: syz-executor Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
pstate: 63400005 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : lock_acquire+0x16c/0x368 arch/arm64/include/asm/irqflags.h:-1
lr : lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lr : lock_acquire+0x14c/0x368 kernel/locking/lockdep.c:5870
sp : ffff8000933d7a10
x29: ffff8000933d7a60 x28: 0000000000000000 x27: 0000000000000000
x26: ffff800088920230 x25: 0000000000000000 x24: 0000000000000000
x23: 0000000000000002 x22: ffff800088b673e0 x21: ffff800080b6550c
x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 00000000ffff8000 x13: 0000000000000001 x12: 0000000000000000
x11: ffff80008a3f4d08 x10: 0000000000000003 x9 : 0000000000000000
x8 : 00000000000000c0 x7 : ffff800080b6550c x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002
x2 : 0000000000000008 x1 : ffff0000d34c5700 x0 : 0000000000000000
Call trace:
 __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] (P)
 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] (P)
 lock_acquire+0x16c/0x368 kernel/locking/lockdep.c:5871 (P)
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock_sched include/linux/rcupdate.h:936 [inline]
 pfn_valid+0xac/0x214 include/linux/mmzone.h:2281
 lowmem_page_address include/linux/mm.h:2973 [inline]
 folio_address include/linux/mm.h:2984 [inline]
 slab_address mm/slab.h:153 [inline]
 nearest_obj mm/slab.h:284 [inline]
 check_slab_allocation+0xac/0x17c mm/kasan/common.c:229
 __kasan_slab_pre_free+0x34/0x44 mm/kasan/common.c:261
 kasan_slab_pre_free include/linux/kasan.h:199 [inline]
 slab_free_hook mm/slub.c:2634 [inline]
 slab_free mm/slub.c:6251 [inline]
 kmem_cache_free+0x148/0x6b8 mm/slub.c:6378
 file_free+0x128/0x1dc fs/file_table.c:104
 __fput+0x538/0x744 fs/file_table.c:523
 fput_close_sync+0x10c/0x278 fs/file_table.c:615
 __do_sys_close fs/open.c:1507 [inline]
 __se_sys_close fs/open.c:1492 [inline]
 __arm64_sys_close+0x7c/0x10c fs/open.c:1492
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1404 Comm: kworker/u8:6 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_unbound toggle_allocation_gate
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : csd_lock_wait kernel/smp.c:342 [inline]
pc : smp_call_function_many_cond+0xfa4/0x1614 kernel/smp.c:892
lr : csd_lock_wait kernel/smp.c:342 [inline]
lr : smp_call_function_many_cond+0xfbc/0x1614 kernel/smp.c:892
sp : ffff800095337780
x29: ffff800095337890 x28: dfff800000000000 x27: ffff0001a5ff5780
x26: 0000000000000011 x25: 0000000000000000 x24: ffff80008897f680
x23: ffffffffffffffff x22: 1fffe00034bfeaf0 x21: 1fffe00034bfeaf1
x20: ffff0001a5fd6b68 x19: ffff0001a5ff5788 x18: 1fffe00034bfbe20
x17: ffff80008897b000 x16: ffff800088a2dc20 x15: ffff0001a5fdf10c
x14: ffff0001a5fdf108 x13: 0000000000000001 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : 0000000000000011 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000000 x3 : ffff8000805a47c4
x2 : 0000000000000000 x1 : ffff0000ca241d00 x0 : 0000000000000000
Call trace:
 __cmpwait_case_32 arch/arm64/include/asm/cmpxchg.h:233 [inline] (P)
 __cmpwait arch/arm64/include/asm/cmpxchg.h:259 [inline] (P)
 csd_lock_wait kernel/smp.c:342 [inline] (P)
 smp_call_function_many_cond+0xfa4/0x1614 kernel/smp.c:892 (P)
 smp_call_function_many kernel/smp.c:915 [inline]
 smp_call_function+0x58/0xbc kernel/smp.c:935
 kick_all_cpus_sync+0x28/0x34 kernel/smp.c:1081
 arch_jump_label_transform_apply+0x14/0x20 arch/arm64/kernel/jump_label.c:34
 __jump_label_update+0x314/0x33c kernel/jump_label.c:521
 jump_label_update+0x41c/0x4a8 kernel/jump_label.c:910
 static_key_enable_cpuslocked+0x11c/0x220 kernel/jump_label.c:210
 static_key_enable+0x24/0x38 kernel/jump_label.c:223
 toggle_allocation_gate+0xb8/0x28c mm/kfence/core.c:906
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0x79c/0x1098 kernel/workqueue.c:3397
 worker_thread+0x754/0xba0 kernel/workqueue.c:3478
 kthread+0x2f8/0x3c8 kernel/kthread.c:436
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:842
watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [kworker/u8:6:1404]
Modules linked in:
irq event stamp: 2752288
hardirqs last  enabled at (2752287): [<ffff8000867ad4a4>] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:507 [inline]
hardirqs last  enabled at (2752287): [<ffff8000867ad4a4>] arm64_exit_to_kernel_mode+0x80/0x94 arch/arm64/kernel/entry-common.c:62
hardirqs last disabled at (2752288): [<ffff8000867a94b4>] __el1_irq arch/arm64/kernel/entry-common.c:506 [inline]
hardirqs last disabled at (2752288): [<ffff8000867a94b4>] el1_interrupt+0x28/0x60 arch/arm64/kernel/entry-common.c:522
softirqs last  enabled at (2752280): [<ffff80008030a098>] softirq_handle_end kernel/softirq.c:468 [inline]
softirqs last  enabled at (2752280): [<ffff80008030a098>] handle_softirqs+0xbc4/0xd34 kernel/softirq.c:650
softirqs last disabled at (2752271): [<ffff8000800204b0>] __do_softirq+0x14/0x20 kernel/softirq.c:656
CPU: 1 UID: 0 PID: 1404 Comm: kworker/u8:6 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_unbound toggle_allocation_gate
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : csd_lock_wait kernel/smp.c:342 [inline]
pc : smp_call_function_many_cond+0xfa4/0x1614 kernel/smp.c:892
lr : csd_lock_wait kernel/smp.c:342 [inline]
lr : smp_call_function_many_cond+0xfbc/0x1614 kernel/smp.c:892
sp : ffff800095337780
x29: ffff800095337890 x28: dfff800000000000 x27: ffff0001a5ff5780
x26: 0000000000000011 x25: 0000000000000000 x24: ffff80008897f680
x23: ffffffffffffffff x22: 1fffe00034bfeaf0 x21: 1fffe00034bfeaf1
x20: ffff0001a5fd6b68 x19: ffff0001a5ff5788 x18: 1fffe00034bfbe20
x17: ffff80008897b000 x16: ffff800088a2dc20 x15: ffff0001a5fdf10c
x14: ffff0001a5fdf108 x13: 0000000000000001 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : 0000000000000011 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000000 x3 : ffff8000805a47c4
x2 : 0000000000000000 x1 : ffff0000ca241d00 x0 : 0000000000000000
Call trace:
 __cmpwait_case_32 arch/arm64/include/asm/cmpxchg.h:233 [inline] (P)
 __cmpwait arch/arm64/include/asm/cmpxchg.h:259 [inline] (P)
 csd_lock_wait kernel/smp.c:342 [inline] (P)
 smp_call_function_many_cond+0xfa4/0x1614 kernel/smp.c:892 (P)
 smp_call_function_many kernel/smp.c:915 [inline]
 smp_call_function+0x58/0xbc kernel/smp.c:935
 kick_all_cpus_sync+0x28/0x34 kernel/smp.c:1081
 arch_jump_label_transform_apply+0x14/0x20 arch/arm64/kernel/jump_label.c:34
 __jump_label_update+0x314/0x33c kernel/jump_label.c:521
 jump_label_update+0x41c/0x4a8 kernel/jump_label.c:910
 static_key_enable_cpuslocked+0x11c/0x220 kernel/jump_label.c:210
 static_key_enable+0x24/0x38 kernel/jump_label.c:223
 toggle_allocation_gate+0xb8/0x28c mm/kfence/core.c:906
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0x79c/0x1098 kernel/workqueue.c:3397
 worker_thread+0x754/0xba0 kernel/workqueue.c:3478
 kthread+0x2f8/0x3c8 kernel/kthread.c:436
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:842
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10668 Comm: syz-executor Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : handle_softirqs+0x1d0/0xd34 kernel/softirq.c:610
lr : handle_softirqs+0x1cc/0xd34 kernel/softirq.c:606
sp : ffff80008e987ee0
x29: ffff80008e987f80 x28: ffff0000d34c5710 x27: 0000000000000386
x26: ffff0000d34c5708 x25: 1fffe0001a698ae1 x24: 0000000000000000
x23: ffff0000d34c5700 x22: dfff800000000000 x21: ffff0001a5fce480
x20: ffff80008891febc x19: ffff0001a5fce480 x18: 0000000000000000
x17: ffff80011d69a000 x16: ffff80008e980000 x15: 0000000000000000
x14: 0000000000000001 x13: 0000000000000001 x12: 0000000000000000
x11: ffff80008015517c x10: 0000000000000003 x9 : 0000000000000000
x8 : 00000000000295d2 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000008 x3 : ffff800080155224
x2 : 0000000000000000 x1 : ffff0000d34c5700 x0 : ffff80011d69a000
Call trace:
 __daif_local_irq_enable arch/arm64/include/asm/irqflags.h:26 [inline] (P)
 arch_local_irq_enable arch/arm64/include/asm/irqflags.h:48 [inline] (P)
 handle_softirqs+0x1d0/0xd34 kernel/softirq.c:606 (P)
 __do_softirq+0x14/0x20 kernel/softirq.c:656
 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:78
 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:889
 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:83
 invoke_softirq kernel/softirq.c:503 [inline]
 __irq_exit_rcu+0x1ac/0x428 kernel/softirq.c:735
 irq_exit_rcu+0x14/0x84 kernel/softirq.c:752
 __el1_irq arch/arm64/kernel/entry-common.c:510 [inline]
 el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:522
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:527
 el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:590
 __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] (P)
 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] (P)
 lock_acquire+0x16c/0x368 kernel/locking/lockdep.c:5871 (P)
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock_sched include/linux/rcupdate.h:936 [inline]
 pfn_valid+0xac/0x214 include/linux/mmzone.h:2281
 lowmem_page_address include/linux/mm.h:2973 [inline]
 folio_address include/linux/mm.h:2984 [inline]
 slab_address mm/slab.h:153 [inline]
 nearest_obj mm/slab.h:284 [inline]
 check_slab_allocation+0xac/0x17c mm/kasan/common.c:229
 __kasan_slab_pre_free+0x34/0x44 mm/kasan/common.c:261
 kasan_slab_pre_free include/linux/kasan.h:199 [inline]
 slab_free_hook mm/slub.c:2634 [inline]
 slab_free mm/slub.c:6251 [inline]
 kmem_cache_free+0x148/0x6b8 mm/slub.c:6378
 file_free+0x128/0x1dc fs/file_table.c:104
 __fput+0x538/0x744 fs/file_table.c:523
 fput_close_sync+0x10c/0x278 fs/file_table.c:615
 __do_sys_close fs/open.c:1507 [inline]
 __se_sys_close fs/open.c:1492 [inline]
 __arm64_sys_close+0x7c/0x10c fs/open.c:1492
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/12 10:47 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 596d152bc5e3 e93da63e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: soft lockup in file_free
* Struck through repros no longer work on HEAD.