syzbot


INFO: task hung in prealloc_shrinker

Status: auto-closed as invalid on 2022/01/12 05:23
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 424d, last: 417d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in prealloc_shrinker 2 951d 1006d 0/1 auto-closed as invalid on 2020/08/25 18:04

Sample crash report:
INFO: task syz-executor.2:3730 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc4-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:26184 pid: 3730 ppid: 10389 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 rwsem_down_write_slowpath+0x7b9/0x11d0 kernel/locking/rwsem.c:1107
 __down_write_common kernel/locking/rwsem.c:1262 [inline]
 __down_write_common kernel/locking/rwsem.c:1259 [inline]
 __down_write kernel/locking/rwsem.c:1271 [inline]
 down_write+0x137/0x150 kernel/locking/rwsem.c:1518
 prealloc_memcg_shrinker mm/vmscan.c:359 [inline]
 prealloc_shrinker+0x13d/0x7c0 mm/vmscan.c:620
 alloc_super+0x84c/0xab0 fs/super.c:270
 sget_fc+0x13e/0x7c0 fs/super.c:531
 vfs_get_super fs/super.c:1135 [inline]
 get_tree_keyed+0x55/0x200 fs/super.c:1196
 vfs_get_tree+0x89/0x2f0 fs/super.c:1498
 fc_mount+0x13/0xc0 fs/namespace.c:994
 mq_create_mount ipc/mqueue.c:473 [inline]
 mq_init_ns+0x414/0x600 ipc/mqueue.c:1689
 create_ipc_ns ipc/namespace.c:58 [inline]
 copy_ipcs+0x36f/0x570 ipc/namespace.c:84
 create_new_namespaces+0x210/0xb20 kernel/nsproxy.c:90
 copy_namespaces+0x391/0x450 kernel/nsproxy.c:178
 copy_process+0x2da7/0x7580 kernel/fork.c:2197
 kernel_clone+0xe7/0xac0 kernel/fork.c:2584
 __do_sys_clone+0xc8/0x110 kernel/fork.c:2701

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2021/10/07 14:11 upstream 5af4055fa813 62ee0987 .config log report info INFO: task hung in prealloc_shrinker
ci-upstream-linux-next-kasan-gce-root 2021/10/14 05:17 linux-next 8006b911c90a 5462d470 .config log report info INFO: task can't die in prealloc_shrinker
* Struck through repros no longer work on HEAD.