INFO: rcu detected stall in print_daily_error_info

Status: auto-obsoleted due to no activity on 2026/09/27 14:08
Subsystems: ext4
Labels: prio:normal
[Documentation on labels]
First crash: 103d, last: 103d
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
8c59bc93 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: rcu detected stall in print_daily_error_info 2026/07/01 01:14 2026/07/01 01:14 2026/07/01 01:58 93f57954

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 ticks this GP) idle=390c/1/0x4000000000000000 softirq=52925/52925 fqs=3
rcu: 	(detected by 0, t=10503 jiffies, g=58673, q=275 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 10816 Comm: syz.1.1128 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x40 kernel/rcu/update.c:319
Code: 48 8d 3d 73 d2 81 04 48 c7 c6 f9 b0 fc 8d 67 48 0f b9 3a 90 eb ca cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 31 c0 83 3d 83 3f 7e 04 00 74 1d 83 3d 5a 71 7e 04 00
RSP: 0018:ffffc90000a083b0 EFLAGS: 00000092
RAX: ffffffff8986f877 RBX: ffffffff89c2e148 RCX: ffff8880273cdd00
RDX: 0000000000010100 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 0000000000000001 R08: ffff888029ebf19f R09: 1ffff110053d7e33
R10: dffffc0000000000 R11: ffffed10053d7e34 R12: ffff88805323d400
R13: ffff888029ebf000 R14: dffffc0000000000 R15: ffff888029ebf340
FS:  00007f992f63a6c0(0000) GS:ffff888125320000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f12f054da08 CR3: 00000000563ec000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 advance_sched+0xa8f/0xc80 net/sched/sch_taprio.c:994
 __run_hrtimer kernel/time/hrtimer.c:2032 [inline]
 __hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2096
 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:console_flush_one_record arch/x86/include/asm/irqflags.h:-1 [inline]
RIP: 0010:console_flush_all+0x7d2/0xaf0 kernel/printk/printk.c:3343
Code: ff ff e8 d1 2d 21 00 90 0f 0b 90 e9 9c fc ff ff e8 c3 2d 21 00 e8 1e 81 0f 0a 48 85 db 74 c0 e8 b4 2d 21 00 fb 48 8b 5c 24 18 <48> 8b 44 24 28 42 80 3c 20 00 4d 8d 77 58 74 08 4c 89 f7 e8 36 b2
RSP: 0018:ffffc90000a08760 EFLAGS: 00000246
RAX: ffffffff81a5340c RBX: ffffc90000a088c0 RCX: ffff8880273cdd00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a08870 R08: ffffffff9032f8f7 R09: 1ffffffff2065f1e
R10: dffffc0000000000 R11: fffffbfff2065f1f R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff8f22fda0
 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
 console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
 _printk+0xdd/0x130 kernel/printk/printk.c:2504
 __ext4_msg+0x2b9/0x2d0 fs/ext4/super.c:1001
 print_daily_error_info+0xaa/0x4d0 fs/ext4/super.c:3697
 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x225/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:188 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:206
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ea d5 ea f5 48 89 df e8 42 4b eb f5 e8 0d 30 17 f6 fb bf 01 00 00 00 <e8> 62 61 dc f5 65 8b 05 3b 92 88 07 85 c0 74 07 5b e9 0c d3 58 f5
RSP: 0018:ffffc900102d5c68 EFLAGS: 00000202
RAX: 00000000000009bf RBX: ffff8880263bb0c8 RCX: 0000000000000001
RDX: 0000000000000006 RSI: ffffffff8dfe3478 RDI: 0000000000000001
RBP: ffff8880263e7490 R08: ffffffff9032f8f7 R09: 1ffffffff2065f1e
R10: dffffc0000000000 R11: fffffbfff2065f1f R12: ffff88802b21e618
R13: ffff88802b21e668 R14: ffff8880263bb0c8 R15: ffff88802b21e660
 spin_unlock_irq include/linux/spinlock.h:402 [inline]
 loop_queue_work drivers/block/loop.c:859 [inline]
 loop_queue_rq+0xa48/0xb50 drivers/block/loop.c:1885
 __blk_mq_issue_directly block/blk-mq.c:2694 [inline]
 blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2754
 blk_mq_submit_bio+0x20f9/0x2a80 block/blk-mq.c:3208
 __submit_bio_noacct_mq block/blk-core.c:756 [inline]
 submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
 ext4_commit_super+0x29b/0x3f0 fs/ext4/super.c:6330
 ext4_handle_error+0x653/0x940 fs/ext4/super.c:725
 __ext4_error+0x24d/0x360 fs/ext4/super.c:837
 ext4_validate_block_bitmap+0x64e/0x6c0 fs/ext4/balloc.c:-1
 ext4_read_block_bitmap_nowait+0x5fb/0x9d0 fs/ext4/balloc.c:557
 ext4_mb_init_cache+0x515/0x1650 fs/ext4/mballoc.c:1430
 ext4_mb_init_group+0x6cf/0xb20 fs/ext4/mballoc.c:1638
 ext4_mb_good_group_nolock fs/ext4/mballoc.c:2833 [inline]
 ext4_mb_scan_group+0x90f/0x18e0 fs/ext4/mballoc.c:2970
 ext4_mb_scan_groups_linear+0xf4/0x370 fs/ext4/mballoc.c:1176
 ext4_mb_scan_groups fs/ext4/mballoc.c:1208 [inline]
 ext4_mb_regular_allocator+0x887/0x2bb0 fs/ext4/mballoc.c:3062
 ext4_mb_new_blocks+0xca7/0x4530 fs/ext4/mballoc.c:6310
 ext4_ext_map_blocks+0x1534/0x5850 fs/ext4/extents.c:4461
 ext4_map_create_blocks+0x116/0x530 fs/ext4/inode.c:631
 ext4_map_blocks+0x7e4/0x1240 fs/ext4/inode.c:824
 ext4_getblk+0x1c3/0x7c0 fs/ext4/inode.c:992
 ext4_bread+0x2a/0x180 fs/ext4/inode.c:1055
 ext4_quota_write+0x23c/0x580 fs/ext4/super.c:7405
 write_blk fs/quota/quota_tree.c:70 [inline]
 get_free_dqblk+0x387/0x740 fs/quota/quota_tree.c:136
 do_insert_tree+0x254/0x11d0 fs/quota/quota_tree.c:347
 do_insert_tree+0x9dc/0x11d0 fs/quota/quota_tree.c:402
 do_insert_tree+0x9dc/0x11d0 fs/quota/quota_tree.c:402
 do_insert_tree+0x9dc/0x11d0 fs/quota/quota_tree.c:402
 dq_insert_tree fs/quota/quota_tree.c:432 [inline]
 qtree_write_dquot+0x49e/0x5e0 fs/quota/quota_tree.c:451
 v2_write_dquot+0x183/0x260 fs/quota/quota_v2.c:372
 dquot_acquire+0x328/0x620 fs/quota/dquot.c:498
 ext4_acquire_dquot+0x2f0/0x4e0 fs/ext4/super.c:7037
 dqget+0x725/0xbd0 fs/quota/dquot.c:1002
 __dquot_initialize+0x3c8/0xd40 fs/quota/dquot.c:1530
 ext4_process_orphan+0x4c/0x2e0 fs/ext4/orphan.c:327
 ext4_orphan_cleanup+0xc7a/0x14c0 fs/ext4/orphan.c:472
 __ext4_fill_super fs/ext4/super.c:5705 [inline]
 ext4_fill_super+0x5cb4/0x65c0 fs/ext4/super.c:5828
 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1634
 vfs_get_tree+0x92/0x2a0 fs/super.c:1694
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3765 [inline]
 do_new_mount+0x319/0xdc0 fs/namespace.c:3841
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f992e79e0ca
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:00007f992f639e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f992f639ee0 RCX: 00007f992e79e0ca
RDX: 00002000000000c0 RSI: 0000200000000640 RDI: 00007f992f639ea0
RBP: 00002000000000c0 R08: 00007f992f639ee0 R09: 0000000003000010
R10: 0000000003000010 R11: 0000000000000246 R12: 0000200000000640
R13: 00007f992f639ea0 R14: 0000000000000524 R15: 0000200000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10490 jiffies! g58673 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27496 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 10790 Comm: syz.6.1125 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: 8b 3d 94 fe 63 0c 48 89 de 5b e9 93 fb 61 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 38 9e 79 11 65 8b 15 59 9e 79 11 81 e2 00 01 ff 00 74
RSP: 0018:ffffc9000ea8f578 EFLAGS: 00000202
RAX: ffffffff81ba4757 RBX: dffffc0000000000 RCX: 0000000000080000
RDX: ffffc9001ded9000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000ea8f6a8 R08: ffffffff9032f8f7 R09: 1ffffffff2065f1e
R10: dffffc0000000000 R11: fffffbfff2065f1f R12: 1ffff110170e81d1
R13: ffff8880b863c448 R14: ffff8880b8740e88 R15: 0000000000000001
FS:  00007f3de73f66c0(0000) GS:ffff888125220000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3ddefffe00 CR3: 0000000069d30000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:342 [inline]
 smp_call_function_many_cond+0x10c7/0x14b0 kernel/smp.c:892
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x5c4/0x1090 arch/x86/mm/tlb.c:1451
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
 tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:423
 tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:549
 unmap_region+0x2a5/0x330 mm/vma.c:491
 vms_clear_ptes mm/vma.c:1303 [inline]
 vms_complete_munmap_vmas+0x427/0xbe0 mm/vma.c:1345
 do_vmi_align_munmap+0x3b7/0x4b0 mm/vma.c:1604
 do_vmi_munmap+0x252/0x2d0 mm/vma.c:1652
 __vm_munmap+0x241/0x3e0 mm/vma.c:3288
 __do_sys_munmap mm/mmap.c:1079 [inline]
 __se_sys_munmap mm/mmap.c:1076 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1076
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3de919cc87
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 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:00007f3de73f5e08 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000000200000 RCX: 00007f3de919cc87
RDX: 0000000000200000 RSI: 0000000008400000 RDI: 00007f3ddee00000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00007f3de73f5ee0 R14: 00007f3de73f5ea0 R15: 00007f3ddee00000
 </TASK>
watchdog: BUG: soft lockup - CPU#0 stuck for 246s! [syz.6.1125:10790]
Modules linked in:
irq event stamp: 735458
hardirqs last  enabled at (735457): [<ffffffff8bb4be38>] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:507 [inline]
hardirqs last  enabled at (735457): [<ffffffff8bb4be38>] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline]
hardirqs last  enabled at (735457): [<ffffffff8bb4be38>] irqentry_exit+0x218/0x8f0 kernel/entry/common.c:167
hardirqs last disabled at (735458): [<ffffffff8bb4abce>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1062
softirqs last  enabled at (735456): [<ffffffff8187eb4a>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last  enabled at (735456): [<ffffffff8187eb4a>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last  enabled at (735456): [<ffffffff8187eb4a>] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
softirqs last disabled at (735373): [<ffffffff8187eb4a>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last disabled at (735373): [<ffffffff8187eb4a>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last disabled at (735373): [<ffffffff8187eb4a>] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
CPU: 0 UID: 0 PID: 10790 Comm: syz.6.1125 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x10b0/0x14b0 kernel/smp.c:892
Code: c0 75 73 41 8b 1e 89 de 83 e6 01 31 ff e8 d8 1e 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 84 1a 0c 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 69 1a 0c
RSP: 0018:ffffc9000ea8f580 EFLAGS: 00000246
RAX: ffffffff81ba4757 RBX: dffffc0000000000 RCX: 0000000000080000
RDX: ffffc9001ded9000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000ea8f6a8 R08: ffffffff9032f8f7 R09: 1ffffffff2065f1e
R10: dffffc0000000000 R11: fffffbfff2065f1f R12: 1ffff110170e81d1
R13: ffff8880b863c448 R14: ffff8880b8740e88 R15: 0000000000000001
FS:  00007f3de73f66c0(0000) GS:ffff888125220000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3ddefffe00 CR3: 0000000069d30000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x5c4/0x1090 arch/x86/mm/tlb.c:1451
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
 tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:423
 tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:549
 unmap_region+0x2a5/0x330 mm/vma.c:491
 vms_clear_ptes mm/vma.c:1303 [inline]
 vms_complete_munmap_vmas+0x427/0xbe0 mm/vma.c:1345
 do_vmi_align_munmap+0x3b7/0x4b0 mm/vma.c:1604
 do_vmi_munmap+0x252/0x2d0 mm/vma.c:1652
 __vm_munmap+0x241/0x3e0 mm/vma.c:3288
 __do_sys_munmap mm/mmap.c:1079 [inline]
 __se_sys_munmap mm/mmap.c:1076 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1076
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3de919cc87
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 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:00007f3de73f5e08 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000000200000 RCX: 00007f3de919cc87
RDX: 0000000000200000 RSI: 0000000008400000 RDI: 00007f3ddee00000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00007f3de73f5ee0 R14: 00007f3de73f5ea0 R15: 00007f3ddee00000
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 10816 Comm: syz.1.1128 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__asan_memset+0x0/0x50 mm/kasan/shadow.c:83
Code: 48 8b 0c 24 ba 01 00 00 00 e9 5c e5 ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 41 56 53 48 89 d3 89 f5 49 89 fe 48 8b 4c 24 18 48
RSP: 0018:ffffc90000a083f8 EFLAGS: 00000046
RAX: 1ffff110053d7e60 RBX: ffff8880b8728460 RCX: dffffc0000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffff888029ebf318
RBP: ffff888029ebf318 R08: ffffffff9a71c203 R09: 1ffffffff34e3840
R10: dffffc0000000000 R11: fffffbfff34e3841 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff110053d7e63 R15: ffff888029ebf300
FS:  00007f992f63a6c0(0000) GS:ffff888125320000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f12f054da08 CR3: 00000000563ec000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 rb_erase_linked+0x142/0x170 lib/rbtree.c:460
 timerqueue_linked_del include/linux/timerqueue.h:66 [inline]
 __remove_hrtimer+0xf7/0x3e0 kernel/time/hrtimer.c:1155
 __run_hrtimer kernel/time/hrtimer.c:2012 [inline]
 __hrtimer_run_queues+0x295/0xa10 kernel/time/hrtimer.c:2096
 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:console_flush_one_record arch/x86/include/asm/irqflags.h:-1 [inline]
RIP: 0010:console_flush_all+0x7d2/0xaf0 kernel/printk/printk.c:3343
Code: ff ff e8 d1 2d 21 00 90 0f 0b 90 e9 9c fc ff ff e8 c3 2d 21 00 e8 1e 81 0f 0a 48 85 db 74 c0 e8 b4 2d 21 00 fb 48 8b 5c 24 18 <48> 8b 44 24 28 42 80 3c 20 00 4d 8d 77 58 74 08 4c 89 f7 e8 36 b2
RSP: 0018:ffffc90000a08760 EFLAGS: 00000246
RAX: ffffffff81a5340c RBX: ffffc90000a088c0 RCX: ffff8880273cdd00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a08870 R08: ffffffff9032f8f7 R09: 1ffffffff2065f1e
R10: dffffc0000000000 R11: fffffbfff2065f1f R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff8f22fda0
 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
 console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
 _printk+0xdd/0x130 kernel/printk/printk.c:2504
 __ext4_msg+0x2b9/0x2d0 fs/ext4/super.c:1001
 print_daily_error_info+0xaa/0x4d0 fs/ext4/super.c:3697
 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x225/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:188 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:206
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ea d5 ea f5 48 89 df e8 42 4b eb f5 e8 0d 30 17 f6 fb bf 01 00 00 00 <e8> 62 61 dc f5 65 8b 05 3b 92 88 07 85 c0 74 07 5b e9 0c d3 58 f5
RSP: 0018:ffffc900102d5c68 EFLAGS: 00000202
RAX: 00000000000009bf RBX: ffff8880263bb0c8 RCX: 0000000000000001
RDX: 0000000000000006 RSI: ffffffff8dfe3478 RDI: 0000000000000001
RBP: ffff8880263e7490 R08: ffffffff9032f8f7 R09: 1ffffffff2065f1e
R10: dffffc0000000000 R11: fffffbfff2065f1f R12: ffff88802b21e618
R13: ffff88802b21e668 R14: ffff8880263bb0c8 R15: ffff88802b21e660
 spin_unlock_irq include/linux/spinlock.h:402 [inline]
 loop_queue_work drivers/block/loop.c:859 [inline]
 loop_queue_rq+0xa48/0xb50 drivers/block/loop.c:1885
 __blk_mq_issue_directly block/blk-mq.c:2694 [inline]
 blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2754
 blk_mq_submit_bio+0x20f9/0x2a80 block/blk-mq.c:3208
 __submit_bio_noacct_mq block/blk-core.c:756 [inline]
 submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
 ext4_commit_super+0x29b/0x3f0 fs/ext4/super.c:6330
 ext4_handle_error+0x653/0x940 fs/ext4/super.c:725
 __ext4_error+0x24d/0x360 fs/ext4/super.c:837
 ext4_validate_block_bitmap+0x64e/0x6c0 fs/ext4/balloc.c:-1
 ext4_read_block_bitmap_nowait+0x5fb/0x9d0 fs/ext4/balloc.c:557
 ext4_mb_init_cache+0x515/0x1650 fs/ext4/mballoc.c:1430
 ext4_mb_init_group+0x6cf/0xb20 fs/ext4/mballoc.c:1638
 ext4_mb_good_group_nolock fs/ext4/mballoc.c:2833 [inline]
 ext4_mb_scan_group+0x90f/0x18e0 fs/ext4/mballoc.c:2970
 ext4_mb_scan_groups_linear+0xf4/0x370 fs/ext4/mballoc.c:1176
 ext4_mb_scan_groups fs/ext4/mballoc.c:1208 [inline]
 ext4_mb_regular_allocator+0x887/0x2bb0 fs/ext4/mballoc.c:3062
 ext4_mb_new_blocks+0xca7/0x4530 fs/ext4/mballoc.c:6310
 ext4_ext_map_blocks+0x1534/0x5850 fs/ext4/extents.c:4461
 ext4_map_create_blocks+0x116/0x530 fs/ext4/inode.c:631
 ext4_map_blocks+0x7e4/0x1240 fs/ext4/inode.c:824
 ext4_getblk+0x1c3/0x7c0 fs/ext4/inode.c:992
 ext4_bread+0x2a/0x180 fs/ext4/inode.c:1055
 ext4_quota_write+0x23c/0x580 fs/ext4/super.c:7405
 write_blk fs/quota/quota_tree.c:70 [inline]
 get_free_dqblk+0x387/0x740 fs/quota/quota_tree.c:136
 do_insert_tree+0x254/0x11d0 fs/quota/quota_tree.c:347
 do_insert_tree+0x9dc/0x11d0 fs/quota/quota_tree.c:402
 do_insert_tree+0x9dc/0x11d0 fs/quota/quota_tree.c:402
 do_insert_tree+0x9dc/0x11d0 fs/quota/quota_tree.c:402
 dq_insert_tree fs/quota/quota_tree.c:432 [inline]
 qtree_write_dquot+0x49e/0x5e0 fs/quota/quota_tree.c:451
 v2_write_dquot+0x183/0x260 fs/quota/quota_v2.c:372
 dquot_acquire+0x328/0x620 fs/quota/dquot.c:498
 ext4_acquire_dquot+0x2f0/0x4e0 fs/ext4/super.c:7037
 dqget+0x725/0xbd0 fs/quota/dquot.c:1002
 __dquot_initialize+0x3c8/0xd40 fs/quota/dquot.c:1530
 ext4_process_orphan+0x4c/0x2e0 fs/ext4/orphan.c:327
 ext4_orphan_cleanup+0xc7a/0x14c0 fs/ext4/orphan.c:472
 __ext4_fill_super fs/ext4/super.c:5705 [inline]
 ext4_fill_super+0x5cb4/0x65c0 fs/ext4/super.c:5828
 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1634
 vfs_get_tree+0x92/0x2a0 fs/super.c:1694
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3765 [inline]
 do_new_mount+0x319/0xdc0 fs/namespace.c:3841
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4367
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f992e79e0ca
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:00007f992f639e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f992f639ee0 RCX: 00007f992e79e0ca
RDX: 00002000000000c0 RSI: 0000200000000640 RDI: 00007f992f639ea0
RBP: 00002000000000c0 R08: 00007f992f639ee0 R09: 0000000003000010
R10: 0000000003000010 R11: 0000000000000246 R12: 0000200000000640
R13: 00007f992f639ea0 R14: 0000000000000524 R15: 0000200000000000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/29 14:04 upstream dc59e4fea9d8 6a0c72dc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in print_daily_error_info
* Struck through repros no longer work on HEAD.