syzbot


INFO: task hung in user_get_super (2)

Status: upstream: reported on 2024/03/30 17:00
Reported-by: syzbot+7622b68a269cb52839d2@syzkaller.appspotmail.com
First crash: 37d, last: 37d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in user_get_super 2 386d 392d 0/3 auto-obsoleted due to no activity on 2023/08/15 03:00
upstream INFO: task hung in user_get_super (2) fs C 251 1d06h 169d 0/26 upstream: reported C repro on 2023/11/19 11:27
linux-5.15 INFO: task hung in user_get_super 6 203d 380d 0/3 auto-obsoleted due to no activity on 2024/01/25 03:23
linux-6.1 INFO: task hung in user_get_super (2) 14 1d08h 168d 0/3 upstream: reported on 2023/11/20 11:19
upstream INFO: task hung in user_get_super fs 1 495d 495d 0/26 auto-obsoleted due to no activity on 2023/04/06 01:17

Sample crash report:
INFO: task syz-executor.4:5895 blocked for more than 143 seconds.
      Not tainted 5.15.153-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:    0 pid: 5895 ppid:  5437 flags:0x00000005
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 rwsem_down_write_slowpath+0xca8/0x1340 kernel/locking/rwsem.c:1157
 __down_write_common kernel/locking/rwsem.c:1284 [inline]
 __down_write kernel/locking/rwsem.c:1293 [inline]
 down_write+0x25c/0x260 kernel/locking/rwsem.c:1542
 user_get_super+0xd8/0x240 fs/super.c:835
 quotactl_block fs/quota/quota.c:889 [inline]
 __do_sys_quotactl fs/quota/quota.c:953 [inline]
 __se_sys_quotactl fs/quota/quota.c:915 [inline]
 __arm64_sys_quotactl+0x4b0/0x7a4 fs/quota/quota.c:915
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
INFO: task syz-executor.4:5897 blocked for more than 143 seconds.
      Not tainted 5.15.153-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:    0 pid: 5897 ppid:  5437 flags:0x00000005
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 rwsem_down_write_slowpath+0xca8/0x1340 kernel/locking/rwsem.c:1157
 __down_write_common kernel/locking/rwsem.c:1284 [inline]
 __down_write kernel/locking/rwsem.c:1293 [inline]
 down_write+0x25c/0x260 kernel/locking/rwsem.c:1542
 user_get_super+0xd8/0x240 fs/super.c:835
 quotactl_block fs/quota/quota.c:889 [inline]
 __do_sys_quotactl fs/quota/quota.c:953 [inline]
 __se_sys_quotactl fs/quota/quota.c:915 [inline]
 __arm64_sys_quotactl+0x4b0/0x7a4 fs/quota/quota.c:915
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014ae14a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311
2 locks held by kworker/u4:3/296:
2 locks held by getty/3719:
 #0: ffff0000d2ff2098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff800018e462e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
5 locks held by syz-executor.0/5122:
4 locks held by syz-executor.4/5249:
1 lock held by syz-executor.4/5895:
 #0: ffff0000c19820e0 (&type->s_umount_key#73){+.+.}-{3:3}, at: user_get_super+0xd8/0x240 fs/super.c:835
1 lock held by syz-executor.4/5897:
 #0: ffff0000c19820e0 (&type->s_umount_key#73){+.+.}-{3:3}, at: user_get_super+0xd8/0x240 fs/super.c:835
1 lock held by syz-executor.0/6167:
 #0: ffff0000d184c0e0 (&type->s_umount_key#73){+.+.}-{3:3}, at: user_get_super+0xd8/0x240 fs/super.c:835
1 lock held by syz-executor.4/6289:
 #0: ffff0000c19820e0 (&type->s_umount_key#73){+.+.}-{3:3}, at: user_get_super+0xd8/0x240 fs/super.c:835
1 lock held by syz-executor.0/7878:
 #0: ffff0000d184c0e0 (&type->s_umount_key#73){+.+.}-{3:3}, at: user_get_super+0xd8/0x240 fs/super.c:835

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


Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/30 17:00 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in user_get_super
* Struck through repros no longer work on HEAD.