INFO: task hung in copy_mnt_ns

Status: premoderation: reported on 2026/09/03 21:19
Reported-by: syzbot+563b19e6e256a1798393@syzkaller.appspotmail.com
First crash: 19h11m, last: 19h11m
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in copy_mnt_ns 1 4 1688d 1716d 0/1 auto-closed as invalid on 2022/05/20 11:54
upstream INFO: task hung in copy_mnt_ns fs 1 3 1698d 1708d 0/29 closed as invalid on 2022/02/08 09:50

Sample crash report:
INFO: task syz-executor:10803 blocked for more than 130 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:10803 tgid:10803 ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6063 [inline]
 __schedule+0x1496/0x20b0 kernel/sched/core.c:7883
 __schedule_loop kernel/sched/core.c:7960 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7975
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8032
 rwsem_down_write_slowpath+0x5c9/0x1b60 kernel/locking/rwsem.c:1239
 __down_write_common kernel/locking/rwsem.c:1383 [inline]
 __down_write kernel/locking/rwsem.c:1392 [inline]
 down_write+0x163/0x2b0 kernel/locking/rwsem.c:1659
 namespace_lock fs/namespace.c:1730 [inline]
 copy_mnt_ns+0x12f/0x8f0 fs/namespace.c:3999
 create_new_namespaces+0xd9/0x6f0 kernel/nsproxy.c:78
 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x4f9/0x920 kernel/fork.c:3385
 __do_sys_unshare kernel/fork.c:3471 [inline]
 __se_sys_unshare kernel/fork.c:3469 [inline]
 __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3469
 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f0e48f9f427
RSP: 002b:00007fff6ab5b2a8 EFLAGS: 00000207 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f0e48f9f427
RDX: 00007fff6ab5b2b0 RSI: 0000000000000007 RDI: 0000000000020000
RBP: 00007f0e492267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000207 R12: 0000000000000008
R13: 0000000000000003 R14: 00007fff6ab5b518 R15: 0000000000000000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/03 21:18 android16-6.12 1eab233d5fae 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in copy_mnt_ns
* Struck through repros no longer work on HEAD.