ci starts bisection 2025-12-07 04:36:35.245270377 +0000 UTC m=+923784.770756480
bisecting fixing commit since 05df91921da664ebba2752a7e45b63e3dddb85de
building syzkaller on 4f67c4aece4f5794be20c6bc99c177e44b1320e8
ensuring issue is reproducible on original commit 05df91921da664ebba2752a7e45b63e3dddb85de
testing commit 05df91921da664ebba2752a7e45b63e3dddb85de gcc
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
kernel signature: ca7f0fc178c212bd15b1c4755dc3d1bbff206009d9288a8512b2ea2cad87134c
all runs: crashed: INFO: task hung in do_coredump
representative crash: INFO: task hung in do_coredump, types: [HANG]
check whether we can drop unnecessary instrumentation
disabling configs for [bug_or_warning kasan locking atomic_sleep memleak ubsan], they are not needed
testing commit 05df91921da664ebba2752a7e45b63e3dddb85de gcc
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
kernel signature: 1880cb0197c390ccaaf8c174e27f51effd19f219b9e4f7b983f22f2e2852b89b
all runs: crashed: INFO: task hung in do_coredump
representative crash: INFO: task hung in do_coredump, types: [HANG]
the bug reproduces without the instrumentation
disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed
kconfig minimization: base=4109 full=8470 leaves diff=2199
split chunks (needed=false): <2199>
split chunk #0 of len 2199 into 5 parts
testing without sub-chunk 1/5
disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed
testing commit 05df91921da664ebba2752a7e45b63e3dddb85de gcc
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
kernel signature: 4ed4ef5338ddc2dff84ff45f34a79745f1571bf21d87f8d324adc91c1ec0aa27
all runs: crashed: INFO: task hung in do_coredump
representative crash: INFO: task hung in do_coredump, types: [HANG]
the chunk can be dropped
testing without sub-chunk 2/5
disabling configs for [atomic_sleep memleak ubsan bug_or_warning kasan locking], they are not needed
testing commit 05df91921da664ebba2752a7e45b63e3dddb85de gcc
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
kernel signature: 64c89d783add1eb2f6e89ff9beeae04f1a67c4a6b9f26a9cb28da43587828c5e
all runs: crashed: INFO: task hung in do_coredump
representative crash: INFO: task hung in do_coredump, types: [HANG]
the chunk can be dropped
testing without sub-chunk 3/5
disabling configs for [bug_or_warning kasan locking atomic_sleep memleak ubsan], they are not needed
testing commit 05df91921da664ebba2752a7e45b63e3dddb85de gcc
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
kernel signature: 8eaa4cc061321bcd25285a2edcc62b87495db6c12d902175f13eed8fd97eded1
all runs: crashed: INFO: task hung in do_coredump
representative crash: INFO: task hung in do_coredump, types: [HANG]
the chunk can be dropped
testing without sub-chunk 4/5
disabling configs for [bug_or_warning kasan locking atomic_sleep memleak ubsan], they are not needed
testing commit 05df91921da664ebba2752a7e45b63e3dddb85de gcc
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
kernel signature: 65b3880ab0fe1198710043858c782c80d1a3a3097045bcb1f795bc308dda2242
all runs: crashed: INFO: task hung in do_coredump
representative crash: INFO: task hung in do_coredump, types: [HANG]
the chunk can be dropped
testing without sub-chunk 5/5
disabling configs for [atomic_sleep memleak ubsan bug_or_warning kasan locking], they are not needed
testing commit 05df91921da664ebba2752a7e45b63e3dddb85de gcc
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
kernel signature: b4efb7ff881c601037e202b785ab721ddcdda95db6eaca3edfc654379a778b4c
all runs: crashed: INFO: task hung in do_coredump
representative crash: INFO: task hung in do_coredump, types: [HANG]
the chunk can be dropped
disabling configs for [memleak ubsan bug_or_warning kasan locking atomic_sleep], they are not needed
testing current HEAD 37bb2e7217b01404e2abf9d90d8e5705a5603b52
testing commit 37bb2e7217b01404e2abf9d90d8e5705a5603b52 gcc
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
kernel signature: 586436aab28aa661229d6c88d603f9e112feeb7d6df863dd6811f1824b169e5d
all runs: crashed: INFO: task hung in vfs_coredump
representative crash: INFO: task hung in vfs_coredump, types: [HANG]
crash still not fixed/happens on the oldest tested release
revisions tested: 8, total time: 2h35m17.953442115s (build: 1h30m19.78703667s, test: 48m25.757138582s)
crash still not fixed or there were kernel test errors
commit msg: Merge tag 'staging-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
crash: INFO: task hung in vfs_coredump
INFO: task syz.3.16:2842 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.16 state:D stack:12456 pid:2842 tgid:2840 ppid:2391 task_flags:0x400740 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x568/0xfa0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x25/0x110 kernel/sched/core.c:6960
schedule_timeout+0x109/0x120 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x99/0x1b0 kernel/sched/completion.c:121
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269
coredump_wait fs/coredump.c:534 [inline]
vfs_coredump+0x272/0x2240 fs/coredump.c:1196
get_signal+0x849/0xa00 kernel/signal.c:3019
arch_do_signal_or_restart+0x38/0x220 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x72/0x490 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x31a/0x370 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f63c9afe929
RSP: 002b:00007f63c93cd0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 00000000000000ca RBX: 00007f63c9d26088 RCX: 00007f63c9afe929
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f63c9d2608c
RBP: 00007f63c9d26080 R08: 00007f63ca85f000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f63c9d2608c
R13: 0000000000000000 R14: 00007ffefae5b610 R15: 00007ffefae5b6f8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff82982100 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff82982100 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff82982100 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x36/0x120 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:5/127:
#0: ffff888100074948 ((wq_completion)events_unbound){....}-{0:0}, at: process_one_work+0x42f/0x660 kernel/workqueue.c:3232
#1: ffffc90000eb3e38 ((work_completion)(&(&kfence_timer)->work)){....}-{0:0}, at: process_one_work+0x1ed/0x660 kernel/workqueue.c:3233
2 locks held by getty/853:
#0: ffff888105adb8a0 (&tty->ldisc_sem){....}-{0:0}, at: tty_ldisc_ref_wait+0x23/0x60 drivers/tty/tty_ldisc.c:243
#1: ffffc900001fb2f0 (&ldata->atomic_read_lock){....}-{3:3}, at: n_tty_read+0x17a/0x670 drivers/tty/n_tty.c:2211
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(none)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x5a/0x90 lib/dump_stack.c:120
nmi_cpu_backtrace+0xd4/0x110 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0xd5/0x140 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x92/0xb0 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0x514/0x620 kernel/hung_task.c:515
kthread+0x107/0x200 kernel/kthread.c:463
ret_from_fork+0x214/0x230 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 4203 Comm: syz.6.19 Not tainted syzkaller #0 PREEMPT(none)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_acquire.constprop.0+0x8/0x5b0 kernel/locking/lockdep.c:5077
Code: e9 bd ab c5 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 41 54 <55> 53 48 83 ec 10 44 8b 15 5f ac 80 01 65 48 8b 1d fb 88 f5 01 45
RSP: 0018:ffffc9000288bc58 EFLAGS: 00000006
RAX: 0000000000000001 RBX: ffff88810af710a8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88810af710a8
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000200
FS: 00007f4c2072f6c0(0000) GS:ffff8882b4aab000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557ce484a8 CR3: 000000011ee05000 CR4: 00000000003506f0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0xa8/0x180 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0xc7/0xd10 kernel/locking/mutex.c:776
io_cqring_do_overflow_flush io_uring/io_uring.c:647 [inline]
io_cqring_wait+0x629/0x6c0 io_uring/io_uring.c:2733
__do_sys_io_uring_enter+0x4e2/0x7a0 io_uring/io_uring.c:3316
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x6e/0x370 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c20cbe929
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:00007f4c2072f038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f4c20ee5fa0 RCX: 00007f4c20cbe929
RDX: 000000000000235c RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f4c20d40b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4c20ee5fa0 R15: 00007ffd3a5a7138