syzbot


INFO: task hung in __xfs_buf_submit

Status: upstream: reported on 2025/04/02 00:57
Reported-by: syzbot+8ffb05c9df4022fc4424@syzkaller.appspotmail.com
First crash: 106d, last: 90d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in __xfs_buf_submit (2) xfs 1 C done inconclusive 7 797d 1422d 0/29 auto-obsoleted due to no activity on 2023/08/23 09:04
upstream INFO: task hung in __xfs_buf_submit xfs 1 1 1891d 1887d 0/29 auto-closed as invalid on 2020/07/12 07:26
upstream INFO: task can't die in p9_fd_close 1 C done 58 1180d 1786d 0/29 closed as dup on 2022/08/26 12:44

Sample crash report:
INFO: task syz.5.856:8659 blocked for more than 143 seconds.
      Not tainted 6.1.134-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.856       state:D stack:25208 pid:8659  ppid:4789   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6561
 schedule+0xbf/0x180 kernel/sched/core.c:6637
 schedule_timeout+0xac/0x300 kernel/time/timer.c:1941
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x350/0x610 kernel/sched/completion.c:138
 xfs_buf_iowait+0xd2/0x510 fs/xfs/xfs_buf.c:1611
 __xfs_buf_submit+0x428/0x830 fs/xfs/xfs_buf.c:1691
 xfs_buf_submit fs/xfs/xfs_buf.c:60 [inline]
 xfs_buf_read_uncached+0x1f7/0x2d0 fs/xfs/xfs_buf.c:925
 xfs_readsb+0x1a9/0x640 fs/xfs/xfs_mount.c:179
 xfs_fs_fill_super+0x601/0x13a0 fs/xfs/xfs_super.c:1530
 get_tree_bdev+0x3fe/0x620 fs/super.c:1366
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x2ba/0xb40 fs/namespace.c:3056
 do_mount fs/namespace.c:3399 [inline]
 __do_sys_mount fs/namespace.c:3607 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f79c278e169
RSP: 002b:00007f79c3601038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f79c29b6160 RCX: 00007f79c278e169
RDX: 0000200000000100 RSI: 00002000000000c0 RDI: 0000200000000040
RBP: 00007f79c2810a68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f79c29b6160 R15: 00007ffc8b25c568
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32e910 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32f110 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
3 locks held by kworker/0:1/14:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc90000137d20 (ser_release_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: ser_release+0x137/0x240 drivers/net/caif/caif_serial.c:307
1 lock held by khungtaskd/28:
 #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
1 lock held by dhcpcd/3917:
 #0: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x29a/0x1ae0 net/ipv4/devinet.c:1081
2 locks held by getty/4010:
 #0: ffff8880305f2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x54a/0x1620 drivers/tty/n_tty.c:2198
2 locks held by kworker/0:7/4298:
 #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc90004107d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
3 locks held by kworker/u4:18/6136:
3 locks held by kworker/0:5/8003:
 #0: ffff88814c769138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc9000f857d20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16e0 net/ipv6/addrconf.c:4134
2 locks held by kworker/1:1/8005:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc9000f877d20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
2 locks held by kworker/1:4/8006:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc9000f887d20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
2 locks held by kworker/1:10/8007:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc9000f897d20 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
3 locks held by kworker/1:13/8010:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc9000f8c7d20 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #2: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962
1 lock held by syz.5.856/8659:
 #0: ffff8880438da0e0 (&type->s_umount_key#91/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228
3 locks held by syz-executor/8749:
 #0: ffff8880440d10b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline]
 #0: ffff8880440d10b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2707
 #1: ffff8880440d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0xfc0 net/bluetooth/hci_sync.c:5165
 #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1799 [inline]
 #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2503
4 locks held by kworker/u4:7/9280:
 #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc90004a2fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: ffffffff8e544210 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x166/0xd20 net/core/net_namespace.c:594
 #3: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: bareudp_exit_batch_net+0xb0/0x1f0 drivers/net/bareudp.c:781
1 lock held by syz-executor/9497:
 #0: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7cb/0x1000 net/core/rtnetlink.c:6150
1 lock held by syz.4.1013/9712:
 #0: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
 #0: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3492
4 locks held by syz.0.1040/9877:
 #0: ffff8880518401c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: __tty_hangup+0xc0/0x620 drivers/tty/tty_io.c:591
 #1: ffff888051840098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:290 [inline]
 #1: ffff888051840098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock+0x68/0xb0 drivers/tty/tty_ldisc.c:314
 #2: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdev+0x79/0x210 net/core/dev.c:11036
 #3: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #3: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.134-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ca/0x430 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4510 Comm: kworker/u4:15 Not tainted 6.1.134-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffc90004787a30 EFLAGS: 00010246
RAX: ffff888027eb0000 RBX: 0000000000000000 RCX: 0000000000000540
RDX: 0000000000001000 RSI: 0000000000000000 RDI: ffff888027eb0ac0
RBP: 0000000000000001 R08: ffffc90004787ab0 R09: ffff888027eb0000
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: 0000000000082a20 R14: 0000000000000001 R15: ffffc90004787ab0
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb23e176440 CR3: 000000002fe3d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 slab_post_alloc_hook+0x71/0x3a0 mm/slab.h:739
 slab_alloc_node mm/slub.c:3398 [inline]
 __kmem_cache_alloc_node+0x137/0x260 mm/slub.c:3437
 __do_kmalloc_node mm/slab_common.c:935 [inline]
 __kmalloc_node_track_caller+0xa0/0x220 mm/slab_common.c:956
 kmalloc_reserve net/core/skbuff.c:446 [inline]
 __alloc_skb+0x12a/0x2c0 net/core/skbuff.c:515
 alloc_skb include/linux/skbuff.h:1271 [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+0x24c/0xab0 drivers/net/netdevsim/dev.c:851
 process_one_work+0x917/0x1260 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/18 03:11 linux-6.1.y 420102835862 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __xfs_buf_submit
2025/04/12 01:33 linux-6.1.y 420102835862 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __xfs_buf_submit
2025/04/11 10:23 linux-6.1.y 420102835862 94486846 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __xfs_buf_submit
2025/04/10 21:59 linux-6.1.y 420102835862 1ef3ab4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __xfs_buf_submit
2025/04/08 15:16 linux-6.1.y 3dfebb87d7eb a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __xfs_buf_submit
2025/04/02 00:59 linux-6.1.y 8e60a714ba3b b8645499 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __xfs_buf_submit
2025/04/02 00:57 linux-6.1.y 8e60a714ba3b b8645499 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __xfs_buf_submit
2025/04/02 00:56 linux-6.1.y 8e60a714ba3b b8645499 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in __xfs_buf_submit
* Struck through repros no longer work on HEAD.