[v6.6] INFO: task hung in write_cache_pages
0 views
Skip to first unread message
syzbot
4:10 AM (14 hours ago) 4:10 AM
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=105b9584580000
kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=7c9faa16485f194ba982
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10640f7c580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17e83f0a580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/84b178f9d4f0/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=13e83f0a580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7c9faa...@syzkaller.appspotmail.com
INFO: task kworker/u4:4:59 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:4 state:D stack:21144 pid:59 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
folio_lock include/linux/pagemap.h:1074 [inline]
write_cache_pages+0x441/0x11f0 mm/page-writeback.c:2463
do_writepages+0x40e/0x600 mm/page-writeback.c:2580
__writeback_single_inode+0x153/0xee0 fs/fs-writeback.c:1635
writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:1997
wb_writeback+0x464/0xba0 fs/fs-writeback.c:2107
wb_check_background_flush fs/fs-writeback.c:2177 [inline]
wb_do_writeback fs/fs-writeback.c:2265 [inline]
wb_workfn+0xb32/0xe20 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
INFO: task jfsCommit:111 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:jfsCommit state:D stack:27560 pid:111 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
txUnlock+0x244/0xcb0 fs/jfs/jfs_txnmgr.c:930
txLazyCommit fs/jfs/jfs_txnmgr.c:2683 [inline]
jfs_lazycommit+0x570/0xa60 fs/jfs/jfs_txnmgr.c:2733
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
INFO: task syz.0.17:5924 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:24912 pid:5924 ppid:5876 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
release_metapage+0x97/0x870 fs/jfs/jfs_metapage.c:764
discard_metapage fs/jfs/jfs_metapage.h:88 [inline]
__get_metapage+0xa69/0xfa0 fs/jfs/jfs_metapage.c:644
dtSearch+0x591/0x21b0 fs/jfs/jfs_dtree.c:624
jfs_lookup+0x156/0x380 fs/jfs/namei.c:1459
lookup_open fs/namei.c:3474 [inline]
open_last_lookups fs/namei.c:3564 [inline]
path_openat+0x10b8/0x3190 fs/namei.c:3794
do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1447
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4f7eb8f749
RSP: 002b:00007ffc4c19c598 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4f7ede5fa0 RCX: 00007f4f7eb8f749
RDX: 0000000000040042 RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f4f7ec13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4f7ede5fa0 R14: 00007f4f7ede5fa0 R15: 0000000000000004
</TASK>
Showing all locks held in the system:
3 locks held by kworker/u4:0/11:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88802ee7a0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:2/42:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90000b2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000b2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880781b00e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:3/49:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880438c80e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:4/59:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900015a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900015a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88802e2720e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:5/1039:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000431fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000431fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88805cc400e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:7/3447:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000c707d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000c707d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88802fef80e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
2 locks held by getty/5519:
#0: ffff88814ce2d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz.0.17/5924:
#0: ffff88806094b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff88806094b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff88806094b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.1.18/5947:
#0: ffff888060a99810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888060a99810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888060a99810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.2.19/5977:
#0: ffff888060a9e210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888060a9e210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888060a9e210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:8/5978:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003657d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003657d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888020c5e0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:9/5979:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003647d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003647d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880277d20e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by syz.3.20/6000:
#0: ffff888073a01810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073a01810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073a01810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.4.21/6027:
#0: ffff888060a57490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888060a57490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888060a57490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
2 locks held by kworker/0:5/6028:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003f47d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003f47d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by syz.5.22/6056:
#0: ffff888073a06210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073a06210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073a06210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:11/6063:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900041dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900041dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888061fe00e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by syz.6.23/6091:
#0: ffff888073a66b50 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073a66b50 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073a66b50 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.7.24/6119:
#0: ffff888060b14650 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888060b14650 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888060b14650 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:13/6121:
5 locks held by kworker/u4:14/6148:
1 lock held by syz.8.25/6149:
#0: ffff8880738c2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff8880738c2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff8880738c2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
2 locks held by syz-executor/6152:
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
2 locks held by dhcpcd/6161:
#0: ffff888061016130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1767 [inline]
#0: ffff888061016130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6121 Comm: kworker/u4:13 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:211 [inline]
RIP: 0010:unwind_next_frame+0x20a/0x2970 arch/x86/kernel/unwind_orc.c:494
Code: 49 81 ff 00 00 a0 8a 0f 93 c0 40 08 e8 4c 89 7c 24 48 0f 85 d7 00 00 00 49 29 df 49 c1 ef 08 8b 05 53 eb 41 0b 48 89 44 24 28 <8d> 68 ff 89 ef 44 89 fe e8 e9 ec 4a 00 44 39 fd 0f 86 4f 1d 00 00
RSP: 0018:ffffc9000458f238 EFLAGS: 00000203
RAX: 000000000009a001 RBX: ffffffff81000000 RCX: ffff88802d3ebc00
RDX: 0000000000000000 RSI: ffffffff8aa00000 RDI: ffffffff81dc9bec
RBP: ffffc9000458f300 R08: ffffc9000458f3d0 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc9000458f308
R13: dffffc0000000000 R14: ffffc9000458f33d R15: 000000000000dc9b
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c79187c168 CR3: 000000000cb30000 CR4: 00000000003506f0
Call Trace:
<TASK>
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:128
__set_page_owner+0x1d/0x60 mm/page_owner.c:192
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
alloc_slab_page+0x5d/0x170 mm/slub.c:1881
allocate_slab mm/slub.c:2028 [inline]
new_slab+0x87/0x2e0 mm/slub.c:2081
___slab_alloc+0xc6d/0x1300 mm/slub.c:3253
__slab_alloc mm/slub.c:3339 [inline]
__slab_alloc_node mm/slub.c:3392 [inline]
slab_alloc_node mm/slub.c:3485 [inline]
__kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3534
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
__alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
alloc_skb include/linux/skbuff.h:1284 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=105b9584580000
kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=7c9faa16485f194ba982
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10640f7c580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17e83f0a580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/84b178f9d4f0/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=13e83f0a580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7c9faa...@syzkaller.appspotmail.com
INFO: task kworker/u4:4:59 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:4 state:D stack:21144 pid:59 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
folio_lock include/linux/pagemap.h:1074 [inline]
write_cache_pages+0x441/0x11f0 mm/page-writeback.c:2463
do_writepages+0x40e/0x600 mm/page-writeback.c:2580
__writeback_single_inode+0x153/0xee0 fs/fs-writeback.c:1635
writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:1997
wb_writeback+0x464/0xba0 fs/fs-writeback.c:2107
wb_check_background_flush fs/fs-writeback.c:2177 [inline]
wb_do_writeback fs/fs-writeback.c:2265 [inline]
wb_workfn+0xb32/0xe20 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
INFO: task jfsCommit:111 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:jfsCommit state:D stack:27560 pid:111 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
txUnlock+0x244/0xcb0 fs/jfs/jfs_txnmgr.c:930
txLazyCommit fs/jfs/jfs_txnmgr.c:2683 [inline]
jfs_lazycommit+0x570/0xa60 fs/jfs/jfs_txnmgr.c:2733
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
INFO: task syz.0.17:5924 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:24912 pid:5924 ppid:5876 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
release_metapage+0x97/0x870 fs/jfs/jfs_metapage.c:764
discard_metapage fs/jfs/jfs_metapage.h:88 [inline]
__get_metapage+0xa69/0xfa0 fs/jfs/jfs_metapage.c:644
dtSearch+0x591/0x21b0 fs/jfs/jfs_dtree.c:624
jfs_lookup+0x156/0x380 fs/jfs/namei.c:1459
lookup_open fs/namei.c:3474 [inline]
open_last_lookups fs/namei.c:3564 [inline]
path_openat+0x10b8/0x3190 fs/namei.c:3794
do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1447
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4f7eb8f749
RSP: 002b:00007ffc4c19c598 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4f7ede5fa0 RCX: 00007f4f7eb8f749
RDX: 0000000000040042 RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f4f7ec13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4f7ede5fa0 R14: 00007f4f7ede5fa0 R15: 0000000000000004
</TASK>
Showing all locks held in the system:
3 locks held by kworker/u4:0/11:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88802ee7a0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:2/42:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90000b2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000b2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880781b00e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:3/49:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880438c80e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:4/59:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900015a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900015a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88802e2720e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:5/1039:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000431fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000431fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88805cc400e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:7/3447:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000c707d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000c707d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88802fef80e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
2 locks held by getty/5519:
#0: ffff88814ce2d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz.0.17/5924:
#0: ffff88806094b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff88806094b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff88806094b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.1.18/5947:
#0: ffff888060a99810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888060a99810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888060a99810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.2.19/5977:
#0: ffff888060a9e210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888060a9e210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888060a9e210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:8/5978:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003657d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003657d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888020c5e0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:9/5979:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003647d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003647d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880277d20e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by syz.3.20/6000:
#0: ffff888073a01810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073a01810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073a01810 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.4.21/6027:
#0: ffff888060a57490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888060a57490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888060a57490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
2 locks held by kworker/0:5/6028:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003f47d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003f47d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by syz.5.22/6056:
#0: ffff888073a06210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073a06210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073a06210 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:11/6063:
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27a538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900041dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900041dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888061fe00e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by syz.6.23/6091:
#0: ffff888073a66b50 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073a66b50 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073a66b50 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.7.24/6119:
#0: ffff888060b14650 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888060b14650 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888060b14650 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:13/6121:
5 locks held by kworker/u4:14/6148:
1 lock held by syz.8.25/6149:
#0: ffff8880738c2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff8880738c2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff8880738c2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
2 locks held by syz-executor/6152:
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
2 locks held by dhcpcd/6161:
#0: ffff888061016130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1767 [inline]
#0: ffff888061016130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6121 Comm: kworker/u4:13 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:211 [inline]
RIP: 0010:unwind_next_frame+0x20a/0x2970 arch/x86/kernel/unwind_orc.c:494
Code: 49 81 ff 00 00 a0 8a 0f 93 c0 40 08 e8 4c 89 7c 24 48 0f 85 d7 00 00 00 49 29 df 49 c1 ef 08 8b 05 53 eb 41 0b 48 89 44 24 28 <8d> 68 ff 89 ef 44 89 fe e8 e9 ec 4a 00 44 39 fd 0f 86 4f 1d 00 00
RSP: 0018:ffffc9000458f238 EFLAGS: 00000203
RAX: 000000000009a001 RBX: ffffffff81000000 RCX: ffff88802d3ebc00
RDX: 0000000000000000 RSI: ffffffff8aa00000 RDI: ffffffff81dc9bec
RBP: ffffc9000458f300 R08: ffffc9000458f3d0 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc9000458f308
R13: dffffc0000000000 R14: ffffc9000458f33d R15: 000000000000dc9b
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c79187c168 CR3: 000000000cb30000 CR4: 00000000003506f0
Call Trace:
<TASK>
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:128
__set_page_owner+0x1d/0x60 mm/page_owner.c:192
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
alloc_slab_page+0x5d/0x170 mm/slub.c:1881
allocate_slab mm/slub.c:2028 [inline]
new_slab+0x87/0x2e0 mm/slub.c:2081
___slab_alloc+0xc6d/0x1300 mm/slub.c:3253
__slab_alloc mm/slub.c:3339 [inline]
__slab_alloc_node mm/slub.c:3392 [inline]
slab_alloc_node mm/slub.c:3485 [inline]
__kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3534
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
__alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
alloc_skb include/linux/skbuff.h:1284 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
Reply all
Reply to author
Forward
0 new messages