INFO: rcu detected stall in lo_ioctl

Status: upstream: reported on 2026/10/05 19:07
Reported-by: syzbot+cbbcfe71dc405cd6259d@syzkaller.appspotmail.com
First crash: 5d04h, last: 5d04h
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in lo_ioctl (8) mm block 1 2 290d 299d 0/29 auto-obsoleted due to no activity on 2026/03/24 20:58
linux-5.15 INFO: rcu detected stall in lo_ioctl (2) 1 1 431d 431d 0/3 auto-obsoleted due to no activity on 2025/11/13 16:37
upstream INFO: rcu detected stall in lo_ioctl (4) block 1 2 1163d 1219d 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 859d 859d 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 2503d 2503d 0/29 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in lo_ioctl (3) kernfs 1 2 1747d 1752d 0/29 closed as invalid on 2022/02/08 10:00
upstream INFO: rcu detected stall in lo_ioctl block 1 193 3019d 3218d 0/29 closed as dup on 2018/05/04 17:09
upstream INFO: rcu detected stall in lo_ioctl (5) block 1 7 801d 890d 0/29 auto-obsoleted due to no activity on 2024/10/29 01:08
upstream INFO: rcu detected stall in lo_ioctl (7) mm 1 1 402d 402d 0/29 auto-obsoleted due to no activity on 2025/12/02 00:39
upstream INFO: rcu detected stall in lo_ioctl (6) block 1 4 604d 673d 0/29 auto-obsoleted due to no activity on 2025/05/14 17:06
upstream BUG: soft lockup in lo_ioctl prio:low kernfs 1 1 147d 143d 0/29 auto-obsoleted due to no activity on 2026/08/14 06:44
android-5-15 BUG: soft lockup in lo_ioctl 1 2 873d 895d 0/2 auto-obsoleted due to no activity on 2024/08/18 12:53

Sample crash report:
Sent skb ffff88804e245c70
No more buffers in queue
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=d824/1/0x4000000000000000 softirq=13840/13840 fqs=0
	(detected by 1, t=10502 jiffies, g=16077, q=234 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5067 Comm: syz.3.272 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:throtl_select_dispatch block/blk-throttle.c:1155 [inline]
RIP: 0010:throtl_pending_timer_fn+0xd72/0x1dd0 block/blk-throttle.c:1217
Code: 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 db 01 00 00 8b 1b 31 ff 89 de e8 99 99 7d fd 85 db 74 07 e8 30 96 7d fd eb 2c <49> 8d 5f 4c 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 ca 01
RSP: 0018:ffffc90000007aa8 EFLAGS: 00000046
RAX: ffffffff8404b047 RBX: 0000000000000000 RCX: 0000000000000100
RDX: ffff88807a47da00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffffffff1901e40 R08: ffffffff8e20d96f R09: 1ffffffff1c41b2d
R10: dffffc0000000000 R11: fffffbfff1c41b2e R12: 0000000000000000
R13: dffffc0000000000 R14: ffff888029633000 R15: ffff888029633010
FS:  00007f06793f66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fe20ff8 CR3: 0000000072d46000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:console_emit_next_record+0x92f/0xb50 kernel/printk/printk.c:2786
Code: 0f 85 af 00 00 00 e8 10 b0 1a 00 0f b6 5c 24 0f 4d 85 f6 75 07 e8 01 b0 1a 00 eb 06 e8 fa af 1a 00 fb 66 43 c7 44 2f 24 f8 f8 <43> c6 44 2f 26 f8 48 b8 f8 f2 f2 f2 f8 f8 f8 f8 48 05 00 06 06 06
RSP: 0018:ffffc9000d926fa0 EFLAGS: 00000246
RAX: ffffffff81679686 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9000dd41000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000d9271c0 R08: ffffffff90b33247 R09: 1ffffffff2166648
R10: dffffc0000000000 R11: fffffbfff2166649 R12: 1ffff92001b24e3f
R13: dffffc0000000000 R14: 0000000000000200 R15: 1ffff92001b24e00
 console_flush_all kernel/printk/printk.c:-1 [inline]
 console_unlock+0x223/0x630 kernel/printk/printk.c:2906
 vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303
 _printk+0xda/0x130 kernel/printk/printk.c:2328
 set_capacity_and_notify+0x348/0x370 block/genhd.c:91
 loop_set_size+0x44/0xa0 drivers/block/loop.c:232
 loop_configure+0xd82/0x1240 drivers/block/loop.c:1096
 lo_ioctl+0x21c/0x1d10 drivers/block/loop.c:1546
 blkdev_ioctl+0x37b/0x740 block/ioctl.c:626
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f067b19de2b
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:00007f06793f5db0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f067b19de2b
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f06793f5ee0 R14: 00007f06793f5ea0 R15: 00007f0670fd6000
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g16077 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=8190
rcu: rcu_preempt kthread starved for 10502 jiffies! g16077 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
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:28112 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 schedule+0xb9/0x180 kernel/sched/core.c:6639
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5067 Comm: syz.3.272 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:throtl_peek_queued block/blk-throttle.c:-1 [inline]
RIP: 0010:throtl_dispatch_tg block/blk-throttle.c:1111 [inline]
RIP: 0010:throtl_select_dispatch block/blk-throttle.c:1152 [inline]
RIP: 0010:throtl_pending_timer_fn+0xa68/0x1dd0 block/blk-throttle.c:1217
Code: 5d 00 83 e3 01 31 ff 89 de e8 b4 9c 7d fd 4c 89 f7 89 de e8 7a 13 00 00 c7 44 24 04 06 00 00 00 e9 5a 01 00 00 e8 38 99 7d fd <c7> 44 24 04 00 00 00 00 e9 48 01 00 00 e8 26 99 7d fd c7 44 24 04
RSP: 0018:ffffc90000007aa8 EFLAGS: 00000046
RAX: ffffffff8404ad48 RBX: ffff888029633038 RCX: ffff88807a47da00
RDX: 0000000000000100 RSI: 0000000000002909 RDI: 0000000000000000
RBP: 1ffffffff1901e40 R08: ffffffff8e20d96f R09: 1ffffffff1c41b2d
R10: dffffc0000000000 R11: fffffbfff1c41b2e R12: 1ffff110052c6607
R13: ffff888029633038 R14: ffff888029633000 R15: ffff888029633010
FS:  00007f06793f66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fe20ff8 CR3: 0000000072d46000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:console_emit_next_record+0x92f/0xb50 kernel/printk/printk.c:2786
Code: 0f 85 af 00 00 00 e8 10 b0 1a 00 0f b6 5c 24 0f 4d 85 f6 75 07 e8 01 b0 1a 00 eb 06 e8 fa af 1a 00 fb 66 43 c7 44 2f 24 f8 f8 <43> c6 44 2f 26 f8 48 b8 f8 f2 f2 f2 f8 f8 f8 f8 48 05 00 06 06 06
RSP: 0018:ffffc9000d926fa0 EFLAGS: 00000246
RAX: ffffffff81679686 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9000dd41000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000d9271c0 R08: ffffffff90b33247 R09: 1ffffffff2166648
R10: dffffc0000000000 R11: fffffbfff2166649 R12: 1ffff92001b24e3f
R13: dffffc0000000000 R14: 0000000000000200 R15: 1ffff92001b24e00
 console_flush_all kernel/printk/printk.c:-1 [inline]
 console_unlock+0x223/0x630 kernel/printk/printk.c:2906
 vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303
 _printk+0xda/0x130 kernel/printk/printk.c:2328
 set_capacity_and_notify+0x348/0x370 block/genhd.c:91
 loop_set_size+0x44/0xa0 drivers/block/loop.c:232
 loop_configure+0xd82/0x1240 drivers/block/loop.c:1096
 lo_ioctl+0x21c/0x1d10 drivers/block/loop.c:1546
 blkdev_ioctl+0x37b/0x740 block/ioctl.c:626
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f067b19de2b
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:00007f06793f5db0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f067b19de2b
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f06793f5ee0 R14: 00007f06793f5ea0 R15: 00007f0670fd6000
 </TASK>
watchdog: BUG: soft lockup - CPU#1 stuck for 225s! [syz.2.274:5075]
Modules linked in:
irq event stamp: 118590
hardirqs last  enabled at (118589): [<ffffffff8a400d46>] asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
hardirqs last disabled at (118590): [<ffffffff8a33b29a>] sysvec_apic_timer_interrupt+0xa/0xc0 arch/x86/kernel/apic/apic.c:1118
softirqs last  enabled at (70364): [<ffffffff814f4aab>] __do_softirq kernel/softirq.c:630 [inline]
softirqs last  enabled at (70364): [<ffffffff814f4aab>] invoke_softirq kernel/softirq.c:470 [inline]
softirqs last  enabled at (70364): [<ffffffff814f4aab>] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
softirqs last disabled at (70327): [<ffffffff814f4aab>] __do_softirq kernel/softirq.c:630 [inline]
softirqs last disabled at (70327): [<ffffffff814f4aab>] invoke_softirq kernel/softirq.c:470 [inline]
softirqs last disabled at (70327): [<ffffffff814f4aab>] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
CPU: 1 PID: 5075 Comm: syz.2.274 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0x1148/0x1250 kernel/smp.c:998
Code: 41 8b 1f 89 de 83 e6 01 31 ff e8 53 02 0b 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 0a e8 df fe 0a 00 e9 34 ff ff ff f3 90 <41> 0f b6 04 1c 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 17 ff ff ff
RSP: 0018:ffffc9000e95f6c0 EFLAGS: 00000246
RAX: ffffffff817747c3 RBX: dffffc0000000000 RCX: 0000000000080000
RDX: ffffc9000c859000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000e95f820 R08: ffffc9000e95f647 R09: 1ffff92001d2bec8
R10: dffffc0000000000 R11: fffff52001d2bec9 R12: 1ffff110171c85f5
R13: ffff8880b8f3bd80 R14: 0000000000000000 R15: ffff8880b8e42fa8
FS:  00007f298006a6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc34845ff8 CR3: 000000007bfa7000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1165
 invalidate_bdev+0x8a/0xb0 block/bdev.c:85
 btrfs_get_bdev_and_sb+0x10b/0x190 fs/btrfs/volumes.c:518
 btrfs_open_one_device fs/btrfs/volumes.c:611 [inline]
 open_fs_devices+0x1ca/0xe60 fs/btrfs/volumes.c:1280
 btrfs_mount_root+0x533/0x930 fs/btrfs/super.c:1806
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632
 vfs_get_tree+0x88/0x270 fs/super.c:1584
 fc_mount fs/namespace.c:1048 [inline]
 vfs_kern_mount+0xba/0x150 fs/namespace.c:1078
 btrfs_mount+0x329/0xb10 fs/btrfs/super.c:1894
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632
 vfs_get_tree+0x88/0x270 fs/super.c:1584
 do_new_mount+0x247/0xa40 fs/namespace.c:3078
 do_mount fs/namespace.c:3421 [inline]
 __do_sys_mount fs/namespace.c:3629 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f297f19f40a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2980069e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2980069ee0 RCX: 00007f297f19f40a
RDX: 0000200000000200 RSI: 0000200000005600 RDI: 00007f2980069ea0
RBP: 0000200000000200 R08: 00007f2980069ee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000005600
R13: 00007f2980069ea0 R14: 00000000000055d0 R15: 00002000000004c0
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5067 Comm: syz.3.272 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x7e/0x80 kernel/kcov.c:311
Code: 8d 52 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 <c3> 90 48 8b 04 24 65 48 8b 0d d4 24 80 7e 65 8b 15 d5 24 80 7e 81
RSP: 0018:ffffc90000007aa0 EFLAGS: 00000046
RAX: ffffffff8404b0df RBX: 0000000000000004 RCX: 0000000000000100
RDX: ffff88807a47da00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffffffff1901e40 R08: ffffffff8e20d96f R09: 1ffffffff1c41b2d
R10: dffffc0000000000 R11: fffffbfff1c41b2e R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff110052c662f R15: ffff888029633010
FS:  00007f06793f66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fe20ff8 CR3: 0000000072d46000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 throtl_dequeue_tg block/blk-throttle.c:566 [inline]
 throtl_select_dispatch block/blk-throttle.c:1158 [inline]
 throtl_pending_timer_fn+0xdff/0x1dd0 block/blk-throttle.c:1217
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:console_emit_next_record+0x92f/0xb50 kernel/printk/printk.c:2786
Code: 0f 85 af 00 00 00 e8 10 b0 1a 00 0f b6 5c 24 0f 4d 85 f6 75 07 e8 01 b0 1a 00 eb 06 e8 fa af 1a 00 fb 66 43 c7 44 2f 24 f8 f8 <43> c6 44 2f 26 f8 48 b8 f8 f2 f2 f2 f8 f8 f8 f8 48 05 00 06 06 06
RSP: 0018:ffffc9000d926fa0 EFLAGS: 00000246
RAX: ffffffff81679686 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9000dd41000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000d9271c0 R08: ffffffff90b33247 R09: 1ffffffff2166648
R10: dffffc0000000000 R11: fffffbfff2166649 R12: 1ffff92001b24e3f
R13: dffffc0000000000 R14: 0000000000000200 R15: 1ffff92001b24e00
 console_flush_all kernel/printk/printk.c:-1 [inline]
 console_unlock+0x223/0x630 kernel/printk/printk.c:2906
 vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303
 _printk+0xda/0x130 kernel/printk/printk.c:2328
 set_capacity_and_notify+0x348/0x370 block/genhd.c:91
 loop_set_size+0x44/0xa0 drivers/block/loop.c:232
 loop_configure+0xd82/0x1240 drivers/block/loop.c:1096
 lo_ioctl+0x21c/0x1d10 drivers/block/loop.c:1546
 blkdev_ioctl+0x37b/0x740 block/ioctl.c:626
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f067b19de2b
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:00007f06793f5db0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f067b19de2b
RDX: 0000000000000003 RSI: 0000000000004c00 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f06793f5ee0 R14: 00007f06793f5ea0 R15: 00007f0670fd6000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/05 19:06 linux-6.1.y a500ba24937a af63e995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in lo_ioctl
* Struck through repros no longer work on HEAD.