bisecting fixing commit since 42226c989789d8da4af1de0c31070c96726d990c
building syzkaller on 744a39e220cece33e207035facce6c5ae161b775
testing commit 42226c989789d8da4af1de0c31070c96726d990c
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: e5f785b9c97563ea15deef3114f0cdc3496d546a8434902819b54673a2497264
all runs: crashed: INFO: task hung in __xfs_buf_submit
testing current HEAD 30306f6194cadcc29c77f6ddcd416a75bf5c0232
testing commit 30306f6194cadcc29c77f6ddcd416a75bf5c0232
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 7261acc8e178956ed25bfd1c147bcb0b1fbddba63c5085984158e810b8149abf
all runs: crashed: INFO: task hung in __xfs_buf_submit
revisions tested: 2, total time: 25m48.203726898s (build: 13m16.051137296s, test: 11m58.967601568s)
the crash still happens on HEAD
commit msg: Merge tag 'hardening-v5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
crash: INFO: task hung in __xfs_buf_submit
INFO: task syz-executor.0:4099 blocked for more than 143 seconds.
Not tainted 5.19.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:27400 pid: 4099 ppid: 4079 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5116 [inline]
__schedule+0x9cd/0x4af0 kernel/sched/core.c:6428
schedule+0xd2/0x1f0 kernel/sched/core.c:6500
schedule_timeout+0x19d/0x250 kernel/time/timer.c:1911
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x378/0x530 kernel/sched/completion.c:106
xfs_buf_iowait+0x8e/0x420 fs/xfs/xfs_buf.c:1577
__xfs_buf_submit+0x389/0x660 fs/xfs/xfs_buf.c:1657
xfs_buf_submit fs/xfs/xfs_buf.c:59 [inline]
xfs_buf_read_uncached+0x1bd/0x320 fs/xfs/xfs_buf.c:891
xfs_readsb+0x2a9/0x560 fs/xfs/xfs_mount.c:179
xfs_fs_fill_super+0x65b/0x1940 fs/xfs/xfs_super.c:1503
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+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7ff6006890e9
RSP: 002b:00007ff60179a168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff60079bf60 RCX: 00007ff6006890e9
RDX: 0000000020000140 RSI: 0000000020000000 RDI: 00000000200000c0
RBP: 00007ff6006e308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000008002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcf36409df R14: 00007ff60179a300 R15: 0000000000022000
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8b17a3a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6491
2 locks held by getty/3286:
#0: ffff88802518f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x1f/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc90001c282e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xb14/0x1040 drivers/tty/n_tty.c:2124
1 lock held by syz-executor.0/4099:
#0: ffff88801c6200e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x192/0x9e0 fs/super.c:228
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 5.19.0-rc2-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:220 [inline]
watchdog+0x891/0xc20 kernel/hung_task.c:378
kthread+0x299/0x340 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2430 Comm: kworker/u4:6 Not tainted 5.19.0-rc2-syzkaller #0
CPU: 1 PID: 2430 Comm: kworker/u4:6 Not tainted 5.19.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline]
RIP: 0010:kasan_check_range+0x9/0x180 mm/kasan/generic.c:189
Code: b6 f5 bf 00 08 00 00 89 43 0c e8 b2 e4 ff ff 89 43 08 5b 5d c3 66 66 2e 0f 1f 84 00 00 00 00 00 90 48 85 f6 0f 84 3c 01 00 00 <49> 89 f9 41 54 44 0f b6 c2 49 01 f1 55 53 0f 82 18 01 00 00 48 b8
RSP: 0018:ffffc9000c377780 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 0000000000000008 RCX: ffffffff8154b5e6
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8f39b900
RBP: ffff88802535ab8a R08: 0000000000000000 R09: 0000000000000005
R10: fffffbfff1e73722 R11: 0000000000000001 R12: ffff88802535ab68
R13: ffff88802535a040 R14: 0000000000000000 R15: b85289586e3e3734
FS: 0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4696903990 CR3: 000000000ae8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
instrument_atomic_read include/linux/instrumented.h:71 [inline]
test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
hlock_class kernel/locking/lockdep.c:227 [inline]
__lock_acquire+0x1416/0x55d0 kernel/locking/lockdep.c:5049
lock_acquire kernel/locking/lockdep.c:5665 [inline]
lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630
__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:1830
get_locked_pte include/linux/mm.h:2132 [inline]
__text_poke+0x1b3/0x8e0 arch/x86/kernel/alternative.c:1052
text_poke arch/x86/kernel/alternative.c:1137 [inline]
text_poke_bp_batch+0x44c/0x6d0 arch/x86/kernel/alternative.c:1483
text_poke_flush arch/x86/kernel/alternative.c:1589 [inline]
text_poke_flush arch/x86/kernel/alternative.c:1586 [inline]
text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1596
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:808 [inline]
toggle_allocation_gate+0xe3/0x310 mm/kfence/core.c:800
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:302
----------------
Code disassembly (best guess):
0: b6 f5 mov $0xf5,%dh
2: bf 00 08 00 00 mov $0x800,%edi
7: 89 43 0c mov %eax,0xc(%rbx)
a: e8 b2 e4 ff ff callq 0xffffe4c1
f: 89 43 08 mov %eax,0x8(%rbx)
12: 5b pop %rbx
13: 5d pop %rbp
14: c3 retq
15: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1)
1c: 00 00 00 00
20: 90 nop
21: 48 85 f6 test %rsi,%rsi
24: 0f 84 3c 01 00 00 je 0x166
* 2a: 49 89 f9 mov %rdi,%r9 <-- trapping instruction
2d: 41 54 push %r12
2f: 44 0f b6 c2 movzbl %dl,%r8d
33: 49 01 f1 add %rsi,%r9
36: 55 push %rbp
37: 53 push %rbx
38: 0f 82 18 01 00 00 jb 0x156
3e: 48 rex.W
3f: b8 .byte 0xb8