syzbot


INFO: task hung in xfs_ilock

Status: upstream: reported on 2024/06/05 20:46
Reported-by: syzbot+09a7ddf1ed061bbb2528@syzkaller.appspotmail.com
First crash: 12d, last: 12d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in xfs_ilock 1 12d 12d 0/3 upstream: reported on 2024/06/05 19:00
upstream INFO: task hung in xfs_ilock xfs 7 180d 218d 0/27 auto-obsoleted due to no activity on 2024/03/20 00:19

Sample crash report:
INFO: task syz-executor.4:4720 blocked for more than 143 seconds.
      Not tainted 6.1.92-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:23176 pid:4720  ppid:3565   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 rwsem_down_read_slowpath kernel/locking/rwsem.c:1094 [inline]
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read_nested+0x703/0xa40 kernel/locking/rwsem.c:1646
 xfs_ilock+0x1e6/0x430 fs/xfs/xfs_inode.c:206
 __xfs_filemap_fault+0x3fa/0x9e0 fs/xfs/xfs_file.c:1326
 do_page_mkwrite+0x1a1/0x5f0 mm/memory.c:2992
 wp_page_shared+0x164/0x380 mm/memory.c:3341
 handle_pte_fault mm/memory.c:5031 [inline]
 __handle_mm_fault mm/memory.c:5155 [inline]
 handle_mm_fault+0x2525/0x5340 mm/memory.c:5276
 do_user_addr_fault arch/x86/mm/fault.c:1371 [inline]
 handle_page_fault arch/x86/mm/fault.c:1462 [inline]
 exc_page_fault+0x26f/0x660 arch/x86/mm/fault.c:1518
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7f57fac2ba61
RSP: 002b:00007ffdef7b1d70 EFLAGS: 00010246
RAX: 0000000020000200 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00005555573c1360
RBP: 00007ffdef7b1e68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00007ffdef7b1e90
R13: 00007f57fadb3f8c R14: 0000000000000032 R15: 00007f57fadb5980
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d12ae50 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d12b650 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
5 locks held by kworker/0:1/14:
1 lock held by khungtaskd/28:
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by getty/3301:
 #0: ffff88814b705098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: 
ffffc900031262f0
 (
&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2188
1 lock held by syz-fuzzer/3555:
5 locks held by kworker/u4:5/3607:
 #0: ffff888012616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: 
ffffc90003f6fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffffffff8e28ecd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:566
 #3: ffffffff8e29b028 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xc9/0x330 net/ipv4/ip_tunnel.c:1148
 #4: ffffffff8d130278 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchro

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/05 20:45 linux-6.1.y 88690811da69 5aa1a7c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in xfs_ilock
* Struck through repros no longer work on HEAD.