syzbot |
sign-in | mailing list | source | docs |
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=74f/1/0x4000000000000000 softirq=22189/22193 fqs=5 (detected by 0, t=10502 jiffies, g=26457, q=249) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8789 Comm: syz.1.1029 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4724 [inline] RIP: 0010:__lock_acquire+0xb22/0x7c60 kernel/locking/lockdep.c:4962 Code: c1 0f 8c f5 fe ff ff 48 c7 c7 48 c9 69 8d e8 e5 29 60 00 49 b8 00 00 00 00 00 fc ff df e9 da fe ff ff 44 38 ac 24 c8 00 00 00 <4c> 8b 6c 24 30 4c 8b 64 24 18 4c 8b 7c 24 78 76 38 e8 08 a8 7b 02 RSP: 0018:ffffc90000dd08c0 EFLAGS: 00000097 RAX: 0000000000000000 RBX: ffff88807ae928a8 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffbd0c0 RBP: ffffc90000dd0b10 R08: dffffc0000000000 R09: fffffbfff1ff7a19 R10: fffffbfff1ff7a19 R11: 1ffffffff1ff7a18 R12: 0000000000000000 R13: ffff88807ae92802 R14: 0000000000000001 R15: ffff88807ae92894 FS: 00007fc5e160d6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c29a24b CR3: 000000007f3cd000 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 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] advance_sched+0x6ca/0x940 net/sched/sch_taprio.c:769 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 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:unix_wait_for_peer+0x14c/0x2e0 net/unix/af_unix.c:1309 Code: 4c 89 ee 48 83 e6 01 31 ff e8 20 bb ee f8 49 83 e5 01 0f 85 b0 00 00 00 4d 8d af 80 04 00 00 4c 89 e8 48 c1 e8 03 0f b6 04 18 <84> c0 0f 85 29 01 00 00 45 0f b6 6d 00 44 89 ee 83 e6 01 31 ff e8 RSP: 0018:ffffc90003d4f680 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff88807ae91dc0 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003d4f770 R08: dffffc0000000000 R09: ffffed100f703a0d R10: ffffed100f703a0d R11: 1ffff1100f703a0c R12: ffff88807b81d6c0 R13: ffff88807b81d480 R14: 1ffff920007a9ed4 R15: ffff88807b81d000 unix_dgram_sendmsg+0x106f/0x1890 net/unix/af_unix.c:1910 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490 __sys_sendmmsg+0x27c/0x4a0 net/socket.c:2576 __do_sys_sendmmsg net/socket.c:2605 [inline] __se_sys_sendmmsg net/socket.c:2602 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2602 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: 0033:0x7fc5e33a5ec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc5e160d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007fc5e35fcfa0 RCX: 00007fc5e33a5ec9 RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007fc5e3428f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc5e35fd038 R14: 00007fc5e35fcfa0 R15: 00007ffeb4e82348 </TASK> rcu: rcu_preempt kthread starved for 10485 jiffies! g26457 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:28032 pid: 15 ppid: 2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 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: NMI backtrace for cpu 0 CPU: 0 PID: 8803 Comm: syz.3.1033 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: <IRQ> dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 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:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0xb98/0xd70 kernel/smp.c:969 Code: 89 de 83 e6 01 31 ff e8 66 49 0b 00 83 e3 01 75 07 e8 fc 45 0b 00 eb 43 f3 90 48 b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 d5 45 0b 00 eb d9 44 RSP: 0018:ffffc9000339f8c0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc9000e43b000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9000339f9f0 R08: dffffc0000000000 R09: fffffbfff1ff7a4e R10: fffffbfff1ff7a4e R11: 1ffffffff1ff7a4d R12: ffff8880b91405c8 R13: 1ffff110172280b9 R14: ffff8880b903b3c0 R15: 0000000000000001 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135 kill_bdev block/bdev.c:76 [inline] set_blocksize+0x2eb/0x370 block/bdev.c:157 sb_set_blocksize+0x45/0xe0 block/bdev.c:166 udf_load_vrs+0x85/0xad0 fs/udf/super.c:2016 udf_fill_super+0x69f/0x18f0 fs/udf/super.c:2220 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3025 do_mount fs/namespace.c:3368 [inline] __do_sys_mount fs/namespace.c:3576 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3553 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: 0033:0x7fa6f01e166a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa6ee446e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fa6ee446ef0 RCX: 00007fa6f01e166a RDX: 0000200000000f00 RSI: 00002000000000c0 RDI: 00007fa6ee446eb0 RBP: 0000200000000f00 R08: 00007fa6ee446ef0 R09: 0000000000a00000 R10: 0000000000a00000 R11: 0000000000000246 R12: 00002000000000c0 R13: 00007fa6ee446eb0 R14: 0000000000000c59 R15: 0000200000000300 </TASK>
| Time | Kernel | Commit | Syzkaller | Config | Log | Report | Syz repro | C repro | VM info | Assets (help?) | Manager | Title |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025/10/13 19:16 | linux-5.15.y | 29e53a5b1c4f | b6605ba8 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci2-linux-5-15-kasan | INFO: rcu detected stall in sys_sendmmsg | ||
| 2025/10/10 06:08 | linux-5.15.y | 29e53a5b1c4f | ff1712fe | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci2-linux-5-15-kasan | INFO: rcu detected stall in sys_sendmmsg |