bisecting fixing commit since f21b807c3cf8cd7c5ca9e406b27bf1cd2f1c1238
building syzkaller on 1ba81399e2d03b53a7e631c4ab05f25af1fb1911
testing commit f21b807c3cf8cd7c5ca9e406b27bf1cd2f1c1238
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 8b21325b923fb20a897d5cf3ff1b49eb35e00ef1ffefe76ca64cf7567fdeef74
all runs: crashed: INFO: task hung in ext4_fill_super
testing current HEAD ec7f49619d8ee13e108740c82f942cd401b989e9
testing commit ec7f49619d8ee13e108740c82f942cd401b989e9
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: dba27bb700643cbf08fd4b6b2f7891148c00f21dea8e36818f80cc99e5a410fc
all runs: crashed: INFO: task hung in ext4_stop_mmpd
revisions tested: 2, total time: 24m26.732974221s (build: 12m13.589663635s, test: 11m29.872083388s)
the crash still happens on HEAD
commit msg: Merge tag 'drm-fixes-2022-05-14' of git://anongit.freedesktop.org/drm/drm
crash: INFO: task hung in ext4_stop_mmpd
INFO: task syz-executor.0:4364 blocked for more than 143 seconds.
Not tainted 5.18.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:27656 pid: 4364 ppid: 4099 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5073 [inline]
__schedule+0x913/0x26a0 kernel/sched/core.c:6388
schedule+0xd2/0x1f0 kernel/sched/core.c:6460
schedule_timeout+0x19d/0x250 kernel/time/timer.c:1860
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x373/0x530 kernel/sched/completion.c:106
kthread_stop+0x104/0x4f0 kernel/kthread.c:708
ext4_stop_mmpd+0x34/0xb0 fs/ext4/mmp.c:255
__ext4_fill_super fs/ext4/super.c:5554 [inline]
ext4_fill_super+0x88bb/0xc290 fs/ext4/super.c:5603
get_tree_bdev+0x398/0x680 fs/super.c:1292
vfs_get_tree+0x7f/0x2c0 fs/super.c:1497
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x7e8/0x1a40 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x1f5/0x260 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x467afa
RSP: 002b:00007f370bbbffa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000380 RCX: 0000000000467afa
RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 00007f370bbc0000
RBP: 00007f370bbc0040 R08: 00007f370bbc0040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000
R13: 00000000200000c0 R14: 00007f370bbc0000 R15: 0000000020000200
Showing all locks held in the system:
1 lock held by khungtaskd/28:
#0: ffffffff8af76920 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6467
5 locks held by kworker/u4:3/218:
2 locks held by getty/3312:
#0: ffff88807f6f8098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x1f/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc900028e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x9d7/0xed0 drivers/tty/n_tty.c:2075
1 lock held by syz-executor.0/4364:
#0: ffff888017a400e0 (&type->s_umount_key#27/1){+.+.}-{3:3}, at: alloc_super+0x192/0x9e0 fs/super.c:228
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 5.18.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x57/0x7d lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x30/0xc0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x140/0x170 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0x88c/0xbf0 kernel/hung_task.c:369
kthread+0x299/0x340 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 11 Comm: kworker/u4:1 Not tainted 5.18.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:hlock_class kernel/locking/lockdep.c:201 [inline]
RIP: 0010:hlock_class kernel/locking/lockdep.c:190 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4727 [inline]
RIP: 0010:__lock_acquire+0x635/0x5660 kernel/locking/lockdep.c:4979
Code: 39 f6 0f 8e 30 01 00 00 48 c7 c0 c8 ce c7 8c 4c 89 64 24 58 45 89 f4 49 bf 00 00 00 00 00 fc ff df 48 c1 e8 03 4c 8b 74 24 28 <4c> 01 f8 48 89 44 24 60 eb 66 48 8d 04 5b 48 c1 e0 06 48 05 60 bc
RSP: 0018:ffffc90000107790 EFLAGS: 00000012
RAX: 1ffffffff198f9d9 RBX: ffff88801034c404 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000005 RDI: ffffffff8f1329d9
RBP: 0000000000000004 R08: dffffc0000000000 R09: ffffffff8f12b857
R10: fffffbfff1e2570a R11: 0000000000000001 R12: 0000000000000000
R13: ffff88801034ba00 R14: ffff88801034c420 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561dd5819680 CR3: 000000000ac8e000 CR4: 0000000000350ef0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5641 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:349 [inline]
__get_locked_pte+0x105/0x210 mm/memory.c:1752
get_locked_pte include/linux/mm.h:2128 [inline]
__text_poke+0x1ae/0x8c0 arch/x86/kernel/alternative.c:1038
text_poke arch/x86/kernel/alternative.c:1121 [inline]
text_poke_bp_batch+0x435/0x6c0 arch/x86/kernel/alternative.c:1436
text_poke_flush arch/x86/kernel/alternative.c:1542 [inline]
text_poke_flush arch/x86/kernel/alternative.c:1539 [inline]
text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1549
arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x15f/0x220 kernel/jump_label.c:177
static_key_enable+0x11/0x20 kernel/jump_label.c:190
toggle_allocation_gate mm/kfence/core.c:774 [inline]
toggle_allocation_gate+0xe3/0x310 mm/kfence/core.c:766
process_one_work+0x865/0x13d0 kernel/workqueue.c:2289
worker_thread+0x598/0xec0 kernel/workqueue.c:2436
kthread+0x299/0x340 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
----------------
Code disassembly (best guess):
0: 39 f6 cmp %esi,%esi
2: 0f 8e 30 01 00 00 jle 0x138
8: 48 c7 c0 c8 ce c7 8c mov $0xffffffff8cc7cec8,%rax
f: 4c 89 64 24 58 mov %r12,0x58(%rsp)
14: 45 89 f4 mov %r14d,%r12d
17: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15
1e: fc ff df
21: 48 c1 e8 03 shr $0x3,%rax
25: 4c 8b 74 24 28 mov 0x28(%rsp),%r14
* 2a: 4c 01 f8 add %r15,%rax <-- trapping instruction
2d: 48 89 44 24 60 mov %rax,0x60(%rsp)
32: eb 66 jmp 0x9a
34: 48 8d 04 5b lea (%rbx,%rbx,2),%rax
38: 48 c1 e0 06 shl $0x6,%rax
3c: 48 rex.W
3d: 05 .byte 0x5
3e: 60 (bad)
3f: bc .byte 0xbc