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INFO: rcu detected stall in lo_ioctl (2)

Status: upstream: reported on 2025/08/05 16:37
Reported-by: syzbot+5f2825f6820e6543360a@syzkaller.appspotmail.com
First crash: 19d, last: 19d
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in lo_ioctl (4) block 1 2 751d 807d 0/29 auto-obsoleted due to no activity on 2023/11/02 10:53
linux-5.15 INFO: rcu detected stall in lo_ioctl 1 1 446d 446d 0/3 auto-obsoleted due to no activity on 2024/09/11 22:21
upstream INFO: rcu detected stall in lo_ioctl (2) mm 1 2 2090d 2091d 0/29 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in lo_ioctl (3) kernfs 1 2 1335d 1339d 0/29 closed as invalid on 2022/02/08 10:00
upstream INFO: rcu detected stall in lo_ioctl block 1 193 2606d 2806d 0/29 closed as dup on 2018/05/04 17:09
upstream INFO: rcu detected stall in lo_ioctl (5) block 1 7 389d 478d 0/29 auto-obsoleted due to no activity on 2024/10/29 01:08
upstream INFO: rcu detected stall in lo_ioctl (6) block 1 4 192d 261d 0/29 auto-obsoleted due to no activity on 2025/05/14 17:06
android-5-15 BUG: soft lockup in lo_ioctl 1 2 461d 483d 0/2 auto-obsoleted due to no activity on 2024/08/18 12:53

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 ticks this GP) idle=52b/1/0x4000000000000000 softirq=13265/13265 fqs=0 
	(detected by 0, t=10502 jiffies, g=15941, q=801)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6123 Comm: syz.3.401 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4686 [inline]
RIP: 0010:__lock_acquire+0x579/0x7c60 kernel/locking/lockdep.c:4962
Code: 48 ba 00 00 00 00 00 fc ff df 0f b6 04 10 84 c0 4c 8b 6c 24 30 0f 85 34 63 00 00 83 3d 3f df af 14 00 0f 84 fe 01 00 00 31 db <48> 81 c3 b8 00 00 00 48 89 d8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85
RSP: 0018:ffffc90000dd08e0 EFLAGS: 00000006
RAX: 00000000000045c0 RBX: ffffffff8f943540 RCX: ffffffff815bffcb
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff8ffb70c8
RBP: ffffc90000dd0b30 R08: dffffc0000000000 R09: fffffbfff1ff6e1a
R10: fffffbfff1ff6e1a R11: 1ffffffff1ff6e19 R12: ffff888025e5e4a0
R13: ffff888025e5d940 R14: 0000000000000000 R15: ffff888025e5e480
FS:  00007f4ea298a6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4e9a571c00 CR3: 000000005eb1e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1694 [inline]
 __hrtimer_run_queues+0x5ff/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:console_unlock+0xd90/0x1200 kernel/printk/printk.c:2749
Code: 00 48 83 7c 24 28 00 75 19 e8 ec 90 18 00 eb 18 e8 e5 90 18 00 e8 40 fa 48 08 48 83 7c 24 28 00 74 e7 e8 d3 90 18 00 fb 31 ff <89> de e8 29 94 18 00 85 db 0f 94 c0 22 44 24 17 3c 01 75 1f e8 b7
RSP: 0018:ffffc90003a16de0 EFLAGS: 00000246
RAX: ffffffff815f334d RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000e569000 RSI: 00000000000056d3 RDI: 0000000000000000
RBP: ffffc90003a17050 R08: dffffc0000000000 R09: fffffbfff1ff6e19
R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: 1ffffffff194c4a5
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffffffff194c49e
 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
 _printk+0xcc/0x110 kernel/printk/printk.c:2299
 set_capacity_and_notify+0x2ba/0x350 block/genhd.c:86
 loop_set_size+0x44/0xa0 drivers/block/loop.c:286
 loop_configure+0xf77/0x1480 drivers/block/loop.c:1308
 lo_ioctl+0x8c8/0x1cf0 drivers/block/loop.c:-1
 blkdev_ioctl+0x33c/0x690 block/ioctl.c:604
 block_ioctl+0xac/0xf0 block/fops.c:496
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4ea4b2276b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f4ea2989dc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f4ea4b2276b
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000028f
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f4ea2989ef0 R14: 00007f4ea2989eb0 R15: 00007f4e9a56a000
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g15941 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=9531
rcu: rcu_preempt kthread starved for 10502 jiffies! g15941 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:27904 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6123 Comm: syz.3.401 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_preemption_disabled+0x4b/0x110 lib/smp_processor_id.c:55
Code: 0d 12 32 5a 76 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f <5d> c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 74
RSP: 0018:ffffc90000dd0ab0 EFLAGS: 00000082
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 758873fed8ccd900
RDX: 0000000000000000 RSI: ffffffff8a599320 RDI: ffffffff8a5992e0
RBP: ffffc90000dd0bf0 R08: dffffc0000000000 R09: fffffbfff1ad2dd6
R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff962a1e40 R15: 1ffff920001ba168
FS:  00007f4ea298a6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4e9a571c00 CR3: 000000005eb1e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline]
 rcu_is_watching+0x11/0xa0 kernel/rcu/tree.c:1123
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0xba/0x870 kernel/locking/lockdep.c:5634
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline]
 _raw_spin_unlock_irqrestore+0x6d/0x100 kernel/locking/spinlock.c:194
 debug_object_activate+0x2d2/0x480 lib/debugobjects.c:712
 debug_hrtimer_activate kernel/time/hrtimer.c:410 [inline]
 debug_activate kernel/time/hrtimer.c:465 [inline]
 enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1074
 __run_hrtimer kernel/time/hrtimer.c:1707 [inline]
 __hrtimer_run_queues+0x65a/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:console_unlock+0xd90/0x1200 kernel/printk/printk.c:2749
Code: 00 48 83 7c 24 28 00 75 19 e8 ec 90 18 00 eb 18 e8 e5 90 18 00 e8 40 fa 48 08 48 83 7c 24 28 00 74 e7 e8 d3 90 18 00 fb 31 ff <89> de e8 29 94 18 00 85 db 0f 94 c0 22 44 24 17 3c 01 75 1f e8 b7
RSP: 0018:ffffc90003a16de0 EFLAGS: 00000246
RAX: ffffffff815f334d RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000e569000 RSI: 00000000000056d3 RDI: 0000000000000000
RBP: ffffc90003a17050 R08: dffffc0000000000 R09: fffffbfff1ff6e19
R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: 1ffffffff194c4a5
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffffffff194c49e
 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
 _printk+0xcc/0x110 kernel/printk/printk.c:2299
 set_capacity_and_notify+0x2ba/0x350 block/genhd.c:86
 loop_set_size+0x44/0xa0 drivers/block/loop.c:286
 loop_configure+0xf77/0x1480 drivers/block/loop.c:1308
 lo_ioctl+0x8c8/0x1cf0 drivers/block/loop.c:-1
 blkdev_ioctl+0x33c/0x690 block/ioctl.c:604
 block_ioctl+0xac/0xf0 block/fops.c:496
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4ea4b2276b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f4ea2989dc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f4ea4b2276b
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000028f
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f4ea2989ef0 R14: 00007f4ea2989eb0 R15: 00007f4e9a56a000
 </TASK>
watchdog: BUG: soft lockup - CPU#0 stuck for 222s! [kworker/0:9:4777]
Modules linked in:
irq event stamp: 200050
hardirqs last  enabled at (200049): [<ffffffff89c00d06>] asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
hardirqs last disabled at (200050): [<ffffffff89a826da>] sysvec_apic_timer_interrupt+0xa/0xc0 arch/x86/kernel/apic/apic.c:1108
softirqs last  enabled at (69362): [<ffffffff81487e9f>] __do_softirq kernel/softirq.c:610 [inline]
softirqs last  enabled at (69362): [<ffffffff81487e9f>] invoke_softirq kernel/softirq.c:450 [inline]
softirqs last  enabled at (69362): [<ffffffff81487e9f>] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
softirqs last disabled at (69293): [<ffffffff81487e9f>] __do_softirq kernel/softirq.c:610 [inline]
softirqs last disabled at (69293): [<ffffffff81487e9f>] invoke_softirq kernel/softirq.c:450 [inline]
softirqs last disabled at (69293): [<ffffffff81487e9f>] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
CPU: 0 PID: 4777 Comm: kworker/0:9 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events fqdir_free_fn
RIP: 0010:__sanitizer_cov_trace_pc+0x58/0x60 kernel/kcov.c:216
Code: 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14 16 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89 3a <c3> 0f 1f 80 00 00 00 00 48 8b 04 24 65 48 8b 0d 34 ab 8a 7e 65 8b
RSP: 0018:ffffc9000263fa38 EFLAGS: 00000293
RAX: ffffffff816c6ba5 RBX: 0000000000000000 RCX: ffff88801afe5940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000263fb30 R08: dffffc0000000000 R09: ffffed1017227679
R10: ffffed1017227679 R11: 1ffff11017227678 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff920004c7f4c
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e193746078 CR3: 0000000063fd9000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:440 [inline]
 smp_call_function_single+0x225/0x490 kernel/smp.c:758
 rcu_barrier+0x25d/0x4b0 kernel/rcu/tree.c:4082
 fqdir_free_fn+0x2f/0x130 net/ipv4/inet_fragment.c:166
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6123 Comm: syz.3.401 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_region_inline mm/kasan/generic.c:172 [inline]
RIP: 0010:kasan_check_range+0x1f/0x290 mm/kasan/generic.c:189
Code: 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 a4 01 00 00 41 57 41 56 53 49 89 f8 49 01 f0 0f 82 57 02 00 00 49 89 f8 <49> c1 e8 2f 41 81 f8 ff ff 01 00 0f 82 43 02 00 00 49 bf 01 00 00
RSP: 0018:ffffc90000dd0b40 EFLAGS: 00000092
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff815c77b9
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8d696ea8
RBP: ffffc90000dd0c70 R08: ffffffff8d696ea8 R09: ffffed100481ee32
R10: ffffed100481ee32 R11: 1ffff1100481ee31 R12: ffff8880240f72e8
R13: dffffc0000000000 R14: ffff8880240f7000 R15: 1ffff920001ba178
FS:  00007f4ea298a6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4e9a571c00 CR3: 000000005eb1e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 cpumask_test_cpu include/linux/cpumask.h:344 [inline]
 cpu_online include/linux/cpumask.h:895 [inline]
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0xa9/0x870 kernel/locking/lockdep.c:5634
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 advance_sched+0x7d0/0x940 net/sched/sch_taprio.c:771
 __run_hrtimer kernel/time/hrtimer.c:1690 [inline]
 __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:console_unlock+0xd90/0x1200 kernel/printk/printk.c:2749
Code: 00 48 83 7c 24 28 00 75 19 e8 ec 90 18 00 eb 18 e8 e5 90 18 00 e8 40 fa 48 08 48 83 7c 24 28 00 74 e7 e8 d3 90 18 00 fb 31 ff <89> de e8 29 94 18 00 85 db 0f 94 c0 22 44 24 17 3c 01 75 1f e8 b7
RSP: 0018:ffffc90003a16de0 EFLAGS: 00000246
RAX: ffffffff815f334d RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000e569000 RSI: 00000000000056d3 RDI: 0000000000000000
RBP: ffffc90003a17050 R08: dffffc0000000000 R09: fffffbfff1ff6e19
R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: 1ffffffff194c4a5
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffffffff194c49e
 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
 _printk+0xcc/0x110 kernel/printk/printk.c:2299
 set_capacity_and_notify+0x2ba/0x350 block/genhd.c:86
 loop_set_size+0x44/0xa0 drivers/block/loop.c:286
 loop_configure+0xf77/0x1480 drivers/block/loop.c:1308
 lo_ioctl+0x8c8/0x1cf0 drivers/block/loop.c:-1
 blkdev_ioctl+0x33c/0x690 block/ioctl.c:604
 block_ioctl+0xac/0xf0 block/fops.c:496
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4ea4b2276b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f4ea2989dc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f4ea4b2276b
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000028f
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f4ea2989ef0 R14: 00007f4ea2989eb0 R15: 00007f4e9a56a000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/05 16:36 linux-5.15.y c79648372d02 37880f40 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in lo_ioctl
* Struck through repros no longer work on HEAD.