syzbot


INFO: task hung in ovl_dir_llseek

Status: auto-obsoleted due to no activity on 2025/03/15 03:57
Subsystems: overlayfs
[Documentation on labels]
First crash: 253d, last: 253d

Sample crash report:
INFO: task syz.0.49:6739 blocked for more than 143 seconds.
      Not tainted 6.13.0-rc2-syzkaller-g2e7aff49b5da #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.49        state:D stack:0     pid:6739  tgid:6720  ppid:6419   flags:0x00000009
Call trace:
 __switch_to+0x414/0x788 arch/arm64/kernel/process.c:701 (T)
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x1744/0x27f0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xbc/0x238 kernel/sched/core.c:6848
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6905
 rwsem_down_write_slowpath+0xd10/0x14c8 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0xb4/0xc0 kernel/locking/rwsem.c:1578
 inode_lock include/linux/fs.h:818 [inline]
 ovl_dir_llseek+0x74/0x2e4 fs/overlayfs/readdir.c:820
 vfs_llseek fs/read_write.c:382 [inline]
 ksys_lseek fs/read_write.c:395 [inline]
 __do_sys_lseek fs/read_write.c:405 [inline]
 __se_sys_lseek fs/read_write.c:403 [inline]
 __arm64_sys_lseek+0x13c/0x1c0 fs/read_write.c:403
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
INFO: task syz.0.49:6740 blocked for more than 143 seconds.
      Not tainted 6.13.0-rc2-syzkaller-g2e7aff49b5da #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.49        state:D stack:0     pid:6740  tgid:6720  ppid:6419   flags:0x00000001
Call trace:
 __switch_to+0x414/0x788 arch/arm64/kernel/process.c:701 (T)
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x1744/0x27f0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xbc/0x238 kernel/sched/core.c:6848
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6905
 __mutex_lock_common+0xeec/0x28f4 kernel/locking/mutex.c:665
 __mutex_lock kernel/locking/mutex.c:735 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:787
 fdget_pos+0x220/0x2ac fs/file.c:1191
 class_fd_pos_constructor include/linux/file.h:85 [inline]
 __do_sys_getdents64 fs/readdir.c:392 [inline]
 __se_sys_getdents64 fs/readdir.c:389 [inline]
 __arm64_sys_getdents64+0xe4/0x490 fs/readdir.c:389
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffff80008fb62560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:336
3 locks held by kworker/u8:5/249:
 #0: ffff0000d2467948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x60c/0x15cc kernel/workqueue.c:3203
 #1: ffff80009bbb7c20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6a4/0x15cc kernel/workqueue.c:3203
 #2: ffff800092891c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:79
3 locks held by kworker/u8:7/669:
 #0: ffff0000c0031148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x60c/0x15cc kernel/workqueue.c:3203
 #1: ffff80009d467c20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x6a4/0x15cc kernel/workqueue.c:3203
 #2: ffff800092891c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:79
2 locks held by kworker/u8:9/735:
2 locks held by kworker/u8:12/2181:
2 locks held by getty/6176:
 #0: ffff0000d7f680a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80009b9eb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41c/0x1228 drivers/tty/n_tty.c:2211
3 locks held by syz.0.49/6721:
2 locks held by syz.0.49/6739:
 #0: ffff0000d26f0d38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x220/0x2ac fs/file.c:1191
 #1: ffff0000dc940cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
 #1: ffff0000dc940cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}, at: ovl_dir_llseek+0x74/0x2e4 fs/overlayfs/readdir.c:820
1 lock held by syz.0.49/6740:
 #0: ffff0000d26f0d38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x220/0x2ac fs/file.c:1191
2 locks held by syz-executor/8977:
 #0: ffff8000928f39b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x28/0x50 net/netlink/genetlink.c:1218
 #1: ffff800092891c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:79
1 lock held by syz-executor/9019:
 #0: ffff800092891c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:79
2 locks held by syz-executor/9324:
 #0: ffff80008f981e30 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire+0x18/0x54 include/linux/srcu.h:157
 #1: ffff800092891c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #1: ffff800092891c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline]
 #1: ffff800092891c68 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xa20/0x1914 net/core/rtnetlink.c:4008
2 locks held by syz.4.560/9495:
2 locks held by sed/9503:

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


Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/15 03:56 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2e7aff49b5da 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in ovl_dir_llseek
* Struck through repros no longer work on HEAD.