syzbot


INFO: task hung in relay_open (2)

Status: upstream: reported syz repro on 2025/12/09 23:04
Subsystems: block trace
[Documentation on labels]
Reported-by: syzbot+16ea22f26882d7e46f35@syzkaller.appspotmail.com
First crash: 358d, last: 11d
Cause bisection: failed (error log, bisect log)
  
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly trace report (Jan 2026) 0 (1) 2026/01/22 21:23
[syzbot] [block?] [trace?] INFO: task hung in relay_open (2) 0 (1) 2025/12/09 23:04
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in relay_open 1 1 392d 392d 0/3 auto-obsoleted due to no activity on 2025/04/09 20:26
linux-6.1 INFO: task hung in relay_open (2) 1 1 241d 241d 0/3 auto-obsoleted due to no activity on 2025/09/08 01:25
linux-5.15 INFO: task hung in relay_open 1 1 111d 111d 0/3 auto-obsoleted due to no activity on 2026/01/15 07:54
upstream INFO: task hung in relay_open block trace 1 2 589d 679d 0/29 auto-obsoleted due to no activity on 2024/09/14 11:45
Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/12/19 23:03 21m retest repro linux-next report log

Sample crash report:
INFO: task syz.2.19:6056 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19        state:D stack:25248 pid:6056  tgid:6055  ppid:5947   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 relay_open+0x3b8/0x920 kernel/relay.c:517
 blk_trace_setup_prepare+0x425/0x5a0 kernel/trace/blktrace.c:716
 blk_trace_setup+0x244/0x3d0 kernel/trace/blktrace.c:789
 blk_trace_ioctl+0x2f9/0x6e0 kernel/trace/blktrace.c:935
 blkdev_ioctl+0x4a2/0x710 block/ioctl.c:780
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fea2af8f749
RSP: 002b:00007fea2bf0d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fea2b1e5fa0 RCX: 00007fea2af8f749
RDX: 0000200000000240 RSI: 00000000c0481273 RDI: 0000000000000003
RBP: 00007fea2b013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fea2b1e6038 R14: 00007fea2b1e5fa0 R15: 00007ffde1a3bc48
 </TASK>
INFO: task syz.4.21:6058 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.21        state:D stack:26184 pid:6058  tgid:6057  ppid:5957   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 relay_open+0x3b8/0x920 kernel/relay.c:517
 blk_trace_setup_prepare+0x425/0x5a0 kernel/trace/blktrace.c:716
 blk_trace_setup+0x244/0x3d0 kernel/trace/blktrace.c:789
 blk_trace_ioctl+0x2f9/0x6e0 kernel/trace/blktrace.c:935
 blkdev_ioctl+0x4a2/0x710 block/ioctl.c:780
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f046d78f749
RSP: 002b:00007f046e673038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f046d9e5fa0 RCX: 00007f046d78f749
RDX: 0000200000000240 RSI: 00000000c0481273 RDI: 0000000000000003
RBP: 00007f046d813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f046d9e6038 R14: 00007f046d9e5fa0 R15: 00007fffac8419a8
 </TASK>
INFO: task syz.3.20:6060 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.20        state:D stack:26776 pid:6060  tgid:6059  ppid:5954   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 relay_open+0x3b8/0x920 kernel/relay.c:517
 blk_trace_setup_prepare+0x425/0x5a0 kernel/trace/blktrace.c:716
 blk_trace_setup+0x244/0x3d0 kernel/trace/blktrace.c:789
 blk_trace_ioctl+0x2f9/0x6e0 kernel/trace/blktrace.c:935
 blkdev_ioctl+0x4a2/0x710 block/ioctl.c:780
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92ec78f749
RSP: 002b:00007f92ed544038 EFLAGS: 00000246
 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f92ec9e5fa0 RCX: 00007f92ec78f749
RDX: 0000200000000240 RSI: 00000000c0481273 RDI: 0000000000000003
RBP: 00007f92ec813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f92ec9e6038 R14: 00007f92ec9e5fa0 R15: 00007fffaeee7358
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:7/1150:
 #0: ffff88814c8c7948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
 #1: ffffc90003ddfb80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
 #2: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8f310348 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
2 locks held by klogd/5190:
3 locks held by udevd/5201:
2 locks held by dhcpcd/5495:
2 locks held by getty/5585:
 #0: ffff88814c2ba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
3 locks held by syz-execprog/5825:
 #0: 
ffff88807d8b9bc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:410 [inline]
ffff88807d8b9bc0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:390 [inline]
ffff88807d8b9bc0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/mmap_lock.c:450
 #1: ffff88807ec85280 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline]
 #1: ffff88807ec85280 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_fault+0x8ff/0x1290 mm/filemap.c:3556
 #2: ffffffff8e04f820 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4374 [inline]
 #2: ffffffff8e04f820 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xb8/0x300 mm/page_alloc.c:4399
6 locks held by syz-execprog/5826:
1 lock held by syz-execprog/5827:
 #0: ffff88807ec85280 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline]
 #0: ffff88807ec85280 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_fault+0x8ff/0x1290 mm/filemap.c:3556
2 locks held by syz-executor/5834:
3 locks held by syz.1.18/6054:
2 locks held by syz.2.19/6056:
 #0: ffff88814173d520 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
 #1: ffffffff8df98a48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:517
2 locks held by syz.4.21/6058:
 #0: ffff888140b91bf0 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
 #1: ffffffff8df98a48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:517
2 locks held by syz.3.20/6060:
 #0: ffff888140b908e0 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
 #1: ffffffff8df98a48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:517
2 locks held by syz.6.23/6210:
 #0: ffff888140b94210 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
 #1: ffffffff8df98a48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:517
2 locks held by syz.5.22/6211:
 #0: ffff888140b92f00
 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
 #1: 
ffffffff8df98a48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:517
2 locks held by syz.9.26/6214:
 #0: ffff888140b97b40 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
 #1: ffffffff8df98a48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:517
2 locks held by syz.7.24/6216:
 #0: ffff888140b95520 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
 #1: ffffffff8df98a48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:517
2 locks held by syz.8.25/6218:
 #0: ffff888140b96830 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
 #1: ffffffff8df98a48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:517
2 locks held by syz.0.27/6323:
 #0: ffff88814173af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
 #1: ffffffff8df98a48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:517
1 lock held by syz.2.29/6335:
 #0: ffff88814173d520 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
1 lock held by syz.1.28/6340:
 #0: ffff88814173c210 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
1 lock held by syz.3.30/6342:
 #0: ffff888140b908e0 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
1 lock held by syz.4.31/6344:
 #0: ffff888140b91bf0 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
1 lock held by syz.6.32/6466:
 #0: ffff888140b94210 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
1 lock held by syz.9.34/6490:
 #0: ffff888140b97b40 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788
1 lock held by syz.5.33/6494:
 #0: ffff888140b92f00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x21c/0x3d0 kernel/trace/blktrace.c:788

Crashes (26):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/05 22:55 linux-next 6987d58a9cbc d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in relay_open
2026/01/15 10:39 upstream 944aacb68baf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in relay_open
2025/11/29 02:24 upstream 4331989728da d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in relay_open
2025/11/27 18:36 upstream 765e56e41a5a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in relay_open
2025/11/22 18:46 upstream 2eba5e05d9bc 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in relay_open
2025/11/07 22:12 upstream 4a0c9b339199 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in relay_open
2025/10/07 05:15 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in relay_open
2025/09/16 06:12 upstream 46a51f4f5eda e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in relay_open
2025/09/04 17:20 upstream b9a10f876409 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in relay_open
2025/08/29 18:37 upstream 07d9df80082b 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in relay_open
2025/08/09 20:56 upstream 038d61fd6422 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in relay_open
2025/08/05 06:51 upstream d2eedaa3909b abdcb213 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in relay_open
2025/08/02 22:36 upstream 038d61fd6422 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in relay_open
2025/07/16 19:06 upstream 155a3c003e55 c118d736 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in relay_open
2025/07/15 02:29 upstream 347e9f5043c8 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in relay_open
2025/06/24 18:53 upstream 78f4e737a53e 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in relay_open
2025/04/27 13:33 upstream 5bc1018675ec c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in relay_open
2025/04/26 03:47 upstream 02ddfb981de8 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in relay_open
2025/04/26 03:15 upstream 02ddfb981de8 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in relay_open
2025/02/02 22:13 upstream 69e858e0b8b2 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in relay_open
2025/10/02 05:21 upstream d3479214c05d a1859138 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in relay_open
2025/05/08 22:34 upstream d76bb1ebb558 dbf35fa1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in relay_open
2025/12/28 02:28 linux-next cc3aa43b44bd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in relay_open
2025/10/06 05:01 linux-next 47a8d4b89844 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in relay_open
2025/09/26 04:46 linux-next 8e2755d7779a 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in relay_open
2025/06/16 05:06 linux-next bc6e0ba6c9ba 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in relay_open
* Struck through repros no longer work on HEAD.