syzbot

INFO: task syz.0.17:4353 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:25136 pid: 4353 ppid:  4306 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 xlog_grant_head_wait+0x359/0x810 fs/xfs/xfs_log.c:256
 xlog_grant_head_check+0x25e/0x380 include/linux/spinlock.h:-1
 xfs_log_reserve+0x32d/0x970 fs/xfs/xfs_log.c:464
 xfs_trans_reserve+0x222/0x690 fs/xfs/xfs_trans.c:197
 xfs_trans_alloc+0x3fc/0x780 fs/xfs/xfs_trans.c:288
 xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
 xfs_attr_set+0x78c/0x1350 fs/xfs/libxfs/xfs_attr.c:772
 xfs_xattr_set+0x13e/0x240 fs/xfs/xfs_xattr.c:59
 __vfs_setxattr+0x3e0/0x420 fs/xattr.c:182
 __vfs_setxattr_noperm+0x129/0x5e0 fs/xattr.c:216
 vfs_setxattr+0x167/0x2e0 fs/xattr.c:303
 do_setxattr fs/xattr.c:588 [inline]
 setxattr+0x36c/0x390 fs/xattr.c:611
 path_setxattr+0x147/0x290 fs/xattr.c:630
 __do_sys_lsetxattr fs/xattr.c:653 [inline]
 __se_sys_lsetxattr fs/xattr.c:649 [inline]
 __x64_sys_lsetxattr+0xb4/0xd0 fs/xattr.c:649
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2f9f233e59
RSP: 002b:00007ffdaaef7998 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007f2f9f4acfa0 RCX: 00007f2f9f233e59
RDX: 00002000000002c0 RSI: 00002000000000c0 RDI: 0000200000000000
RBP: 00007f2f9f2c9d6f R08: 0000000000000002 R09: 0000000000000000
R10: 000000000000fe37 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f9f4acfac R14: 00007f2f9f4acfa0 R15: 00007f2f9f4acfa0
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:1/13:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc90000d27d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff888046a03240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26a/0x33e0 drivers/net/netdevsim/fib.c:1480
1 lock held by khungtaskd/27:
 #0: ffffffff8c31eb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3948:
 #0: ffff88802c835098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
2 locks held by kworker/u4:5/4349:
 #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffff8880b9027888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x499/0x7d0 kernel/sched/psi.c:882
3 locks held by syz.0.17/4353:
 #0: ffff88807c302460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88805b879980 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805b879980 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_setxattr+0x140/0x2e0 fs/xattr.c:302
 #2: ffff88807c302650 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
3 locks held by syz.1.18/4384:
 #0: ffff88807e76a460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88805b87a100 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805b87a100 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_setxattr+0x140/0x2e0 fs/xattr.c:302
 #2: ffff88807e76a650 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
3 locks held by syz.2.19/4414:
 #0: ffff88805b094460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88805bad3000 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805bad3000 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_setxattr+0x140/0x2e0 fs/xattr.c:302
 #2: ffff88805b094650 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
3 locks held by syz.3.20/4437:
 #0: ffff888024770460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88805b87bf00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805b87bf00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_setxattr+0x140/0x2e0 fs/xattr.c:302
 #2: ffff888024770650 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
3 locks held by syz.4.21/4466:
 #0: ffff88807444c460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88805bad4e00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805bad4e00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_setxattr+0x140/0x2e0 fs/xattr.c:302
 #2: ffff88807444c650 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
3 locks held by syz.5.22/4496:
 #0: ffff888074888460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88805bad6c00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805bad6c00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_setxattr+0x140/0x2e0 fs/xattr.c:302
 #2: ffff888074888650 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
3 locks held by syz.6.23/4532:
 #0: ffff88804cd92460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88805b87dd00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805b87dd00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_setxattr+0x140/0x2e0 fs/xattr.c:302
 #2: ffff88804cd92650 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
3 locks held by syz.7.24/4561:
 #0: ffff88804dc10460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff888044c48a80 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff888044c48a80 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_setxattr+0x140/0x2e0 fs/xattr.c:302
 #2: ffff88804dc10650 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
3 locks held by syz.8.25/4591:
 #0: ffff888074616460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff888044c4a880 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff888044c4a880 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_setxattr+0x140/0x2e0 fs/xattr.c:302
 #2: ffff888074616650 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
3 locks held by syz.9.26/4621:
 #0: ffff888147ff2460 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
 #1: ffff88805b87fb00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805b87fb00 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: vfs_setxattr+0x140/0x2e0 fs/xattr.c:302
 #2: ffff888147ff2650 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0xad/0x340 fs/xfs/xfs_trans.c:1047
2 locks held by dhcpcd/4630:
 #0: ffff888077362120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
 #0: ffff888077362120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3213
 #1: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4349 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lock_release+0x0/0x8a0 kernel/locking/lockdep.c:5631
Code: 80 c1 03 38 c1 0f 8c c1 f8 ff ff 48 89 df e8 67 c0 60 00 e9 b4 f8 ff ff bb 2f 00 00 00 e9 ca f8 ff ff 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00
RSP: 0000:ffffc900030cfbd8 EFLAGS: 00000293
RAX: ffffffff8991ccfa RBX: dffffc0000000000 RCX: ffff888027560000
RDX: 0000000000000000 RSI: ffffffff8991ccf5 RDI: ffffffff8c31eb20
RBP: ffff888024ea6fc0 R08: dffffc0000000000 R09: 1ffffffff203aa18
R10: dffffc0000000000 R11: fffffbfff203aa19 R12: 00000000000003c2
R13: fffffffffffffe38 R14: ffff88805b350c80 R15: ffff888024ea6fd0
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5502b1d680 CR3: 000000006eb4f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rcu_read_unlock include/linux/rcupdate.h:773 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline]
 batadv_nc_worker+0x25b/0x5c0 net/batman-adv/network-coding.c:723
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>