syzbot


INFO: rcu detected stall in kcov_close

Status: upstream: reported on 2024/08/12 12:28
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+894cac40ce97c83618bb@syzkaller.appspotmail.com
First crash: 457d, last: 8d20h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [mm?] INFO: rcu detected stall in kcov_close 0 (1) 2024/08/12 12:28
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in kcov_close 1 6 399d 449d 0/3 auto-obsoleted due to no activity on 2024/10/23 16:14
linux-5.15 BUG: soft lockup in kcov_close 1 1 449d 449d 0/3 auto-obsoleted due to no activity on 2024/09/03 09:36
upstream INFO: task hung in release_tty (3) serial 1 3 283d 348d 0/29 auto-obsoleted due to no activity on 2025/02/07 03:06

Sample crash report:
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P11494/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=44029, q=514 ncpus=2)
task:syz.3.1433      state:R  running task     stack:26960 pid:11494 tgid:11492 ppid:5856   task_flags:0x40054c flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
 irqentry_exit+0x36/0x90 kernel/entry/common.c:197
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline]
RIP: 0010:lock_is_held_type+0x57/0x150 kernel/locking/lockdep.c:5936
Code: 85 c0 0f 85 ce 00 00 00 65 4c 8b 25 db 1f 43 08 41 8b 94 24 ec 0a 00 00 85 d2 0f 85 b6 00 00 00 48 89 fd 41 89 f6 9c 8f 04 24 <fa> 48 c7 c7 a0 0d f4 8d 4d 8d ac 24 f0 0a 00 00 45 31 ff e8 61 14
RSP: 0018:ffffc9000bed78d8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000067ac5 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8e5c1160
RBP: ffffffff8e5c1160 R08: 0000000000000006 R09: 0000000000001000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88802e500000
R13: 00000000ffffffff R14: 00000000ffffffff R15: ffffea00019eb148
 lookup_page_ext+0x10d/0x1d0 mm/page_ext.c:254
 page_ext_get+0x58/0x1a0 mm/page_ext.c:528
 __reset_page_owner+0x2b/0x1a0 mm/page_owner.c:294
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
 vfree+0x1fd/0xb50 mm/vmalloc.c:3434
 kcov_put kernel/kcov.c:439 [inline]
 kcov_put kernel/kcov.c:435 [inline]
 kcov_close+0x34/0x60 kernel/kcov.c:535
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x86f/0x2bf0 kernel/exit.c:961
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
 get_signal+0x2673/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff6b258ebe9
RSP: 002b:00007ff6b3360038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: 0000000000019000 RBX: 00007ff6b27b5fa0 RCX: 00007ff6b258ebe9
RDX: 0000000000019000 RSI: 0000200000002000 RDI: 0000000000000005
RBP: 00007ff6b2611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff6b27b6038 R14: 00007ff6b27b5fa0 R15: 00007ffeed4ee2a8
 </TASK>
rcu: rcu_preempt kthread starved for 4316 jiffies! g44029 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:28096 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-syzkaller-11852-g479058002c32 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 4c 63 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d f3 82 17 00 fb f4 <e9> 4c 0d 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c2
RAX: 0000000002c53c3d RBX: 0000000000000001 RCX: ffffffff8b928c29
RDX: 0000000000000000 RSI: ffffffff8de4d731 RDI: ffffffff8c161100
RBP: ffffed1003c5d488 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000000 R12: 0000000000000001
R13: ffff88801e2ea440 R14: ffffffff90aaf390 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881247c6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 000000005fa93000 CR4: 00000000003526f0
DR0: fffffffffffffff8 DR1: 0000000000000006 DR2: 0200000000000000
DR3: 0000000000000008 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x148
 </TASK>
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (126):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/06 20:37 upstream 479058002c32 4bd24a3e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kcov_close
2025/07/21 23:43 upstream 89be9a83ccf1 0b3788a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in kcov_close
2025/07/20 08:48 upstream bf61759db409 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in kcov_close
2025/07/17 08:56 upstream e2291551827f 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kcov_close
2025/07/17 01:14 upstream 155a3c003e55 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/07/15 09:37 upstream 155a3c003e55 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kcov_close
2025/07/13 17:53 upstream 3f31a806a62e 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/07/12 20:21 upstream 379f604cc3dc 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/06/17 12:32 upstream 9afe652958c3 417d98fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/06/01 16:25 upstream 7d4e49a77d99 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/05/24 18:39 upstream b1427432d3b6 ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kcov_close
2025/05/11 16:11 upstream 3ce9925823c7 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kcov_close
2025/05/05 23:32 upstream 92a09c47464d 6ca47dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kcov_close
2025/04/30 14:11 upstream 8bac8898fe39 85a5a23f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kcov_close
2025/04/28 21:26 upstream f15d97df5afa c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/04/11 20:22 upstream 900241a5cc15 12ba9c21 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kcov_close
2025/04/04 02:13 upstream a2cc6ff5ec8f d7ae3a11 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/04/03 06:16 upstream 92b71befc349 996a9618 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/03/28 15:09 upstream acb4f33713b9 49900278 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/03/16 13:14 upstream 31d7109a19f6 e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kcov_close
2025/02/23 21:17 upstream 27102b38b8ca d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kcov_close
2025/02/20 18:58 upstream 87a132e73910 50668798 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/02/16 13:05 upstream 496659003dac 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kcov_close
2025/02/05 15:46 upstream 5c8c229261f1 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/01/19 21:14 upstream 9528d418de4d f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/01/15 02:50 upstream c3812b15000c 7315a7cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2025/01/12 18:50 upstream b62cef9a5c67 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kcov_close
2025/01/10 06:53 upstream 2144da25584e 67d7ec0a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2024/12/31 03:39 upstream ccb98ccef0e5 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2024/12/24 18:42 upstream 9b2ffa6148b1 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kcov_close
2024/12/24 01:09 upstream f07044dd0df0 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in kcov_close
2024/12/21 09:28 upstream 499551201b5f d7f584ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2024/12/20 20:17 upstream 8faabc041a00 1ac6aa80 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kcov_close
2024/12/12 08:24 upstream 231825b2e1ff ff949d25 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2024/12/11 13:07 upstream f92f4749861b ff949d25 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in kcov_close
2024/12/10 06:51 upstream 7cb1b4663150 cfc402b4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kcov_close
2024/12/08 23:51 upstream 62b5a46999c7 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in kcov_close
2024/08/08 12:18 upstream 6a0e38264012 de12cf65 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kcov_close
2024/07/23 15:26 upstream 66ebbdfdeb09 708c10c4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kcov_close
2025/07/31 04:10 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in kcov_close
2024/10/17 01:38 upstream c964ced77262 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in kcov_close
2025/07/19 08:21 net 96e056ffba91 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in kcov_close
2025/05/30 10:56 net 27eab4c64423 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in kcov_close
2025/01/17 20:03 net 5d6a361dc01d 953d1c45 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in kcov_close
2025/01/17 02:55 net ce69b4019001 f9e07a6e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in kcov_close
2025/01/05 05:32 net 1e9b0e1c550c f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in kcov_close
2024/12/22 13:28 net 30b981796b94 d7f584ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in kcov_close
2025/01/16 17:21 net-next 9eb8069d9940 968edaf4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in kcov_close
2025/01/11 01:34 net-next 7b24f164cf00 67d7ec0a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in kcov_close
2025/01/01 08:24 net-next 9268abe611b0 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in kcov_close
2024/12/29 13:00 net-next 9268abe611b0 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in kcov_close
2024/12/11 07:28 net-next 65fb414c93f4 cfc402b4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in kcov_close
2024/12/07 20:19 net-next 860dbab69ad8 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in kcov_close
2025/08/10 08:33 linux-next b1549501188c 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in kcov_close
2025/01/10 09:28 linux-next 7b4b9bf203da 67d7ec0a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in kcov_close
2024/12/24 17:36 linux-next 8155b4ef3466 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in kcov_close
2024/12/09 11:51 linux-next af2ea8ab7a54 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in kcov_close
2024/10/10 23:19 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 4a9fe2a8ac53 8fbfc0c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in kcov_close
2024/07/17 15:49 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci c912bf709078 03114f55 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: rcu detected stall in kcov_close
2025/05/02 20:39 bpf-next f263336a41da b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: soft lockup in kcov_close
* Struck through repros no longer work on HEAD.