syzbot


INFO: task can't die in p9_client_rpc (4)

Status: auto-closed as invalid on 2021/12/20 11:32
Reported-by: syzbot+f7825c5626af6ef4558c@syzkaller.appspotmail.com
First crash: 411d, last: 411d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task can't die in p9_client_rpc 7 827d 856d 0/24 auto-closed as invalid on 2020/10/31 10:21
upstream INFO: task can't die in p9_client_rpc (3) 4 525d 527d 0/24 auto-closed as invalid on 2021/08/28 18:18
upstream INFO: task can't die in p9_client_rpc (2) 2 721d 727d 0/24 auto-closed as invalid on 2021/02/14 08:07

Sample crash report:
INFO: task syz-executor.1:13976 can't die for more than 143 seconds.
task:syz-executor.1  state:R  running task     stack:27328 pid:13976 ppid:  1805 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4965 [inline]
 __schedule+0xa9a/0x4940 kernel/sched/core.c:6246
 schedule+0xd2/0x260 kernel/sched/core.c:6319
 p9_client_rpc+0x403/0x1240 net/9p/client.c:761
 p9_client_read_once+0x22c/0x5f0 net/9p/client.c:1607
 p9_client_read+0x13b/0x1a0 net/9p/client.c:1566
 v9fs_dir_readdir+0x4ac/0x6d0 fs/9p/vfs_dir.c:112
 iterate_dir+0x576/0x700 fs/readdir.c:65
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64 fs/readdir.c:354 [inline]
 __x64_sys_getdents64+0x13a/0x2c0 fs/readdir.c:354
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f94bc786a39
RSP: 002b:00007f94b9cfc188 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f94bc889f60 RCX: 00007f94bc786a39
RDX: 0000000000000034 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007f94bc7e0c5f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffca511c0ef R14: 00007f94b9cfc300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8bb833a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
1 lock held by in:imklog/6248:
2 locks held by rs:main Q:Reg/6249:
 #0: ffff88807b7e8370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
 #1: ffff88807eda6460 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x12d/0x250 fs/read_write.c:647
3 locks held by kworker/u4:10/14679:
2 locks held by agetty/13338:
 #0: ffff888076c94098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252
 #1: ffffc9000428b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113
2 locks held by syz-executor.5/13954:
2 locks held by syz-executor.4/13965:
 #0: ffff888022ff8ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
 #1: ffff88803b044eb8 (&sb->s_type->i_mutex_key#27){++++}-{3:3}, at: iterate_dir+0xcd/0x700 fs/readdir.c:55
2 locks held by syz-executor.1/13976:
2 locks held by syz-executor.2/13978:
 #0: ffff888077652d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
 #1: ffff88803b045510 (&sb->s_type->i_mutex_key#27){++++}-{3:3}, at: iterate_dir+0xcd/0x700 fs/readdir.c:55

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


Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-linux-next-kasan-gce-root 2021/10/21 11:32 linux-next 3196a52aff93 f111d03b .config log report info INFO: task can't die in p9_client_rpc
* Struck through repros no longer work on HEAD.