syzbot


WARNING: suspicious RCU usage in dput

Status: closed as dup on 2021/04/05 03:05
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+bdef67a6b28a89e6fe71@syzkaller.appspotmail.com
First crash: 1113d, last: 1046d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
WARNING: suspicious RCU usage in getname_flags fs 2 1017d 1108d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] WARNING: suspicious RCU usage in dput 1 (2) 2021/04/05 03:04

Sample crash report:
=============================
WARNING: suspicious RCU usage
5.13.0-rc4-syzkaller #0 Not tainted
-----------------------------
kernel/sched/core.c:8304 Illegal context switch in RCU-bh read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 0
no locks held by systemd-udevd/4862.

stack backtrace:
CPU: 0 PID: 4862 Comm: systemd-udevd Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 ___might_sleep+0x229/0x2c0 kernel/sched/core.c:8304
 dput+0x4d/0xbc0 fs/dcache.c:872
 step_into+0x2cf/0x1c80 fs/namei.c:1781
 walk_component+0x171/0x6a0 fs/namei.c:1948
 link_path_walk.part.0+0x712/0xc90 fs/namei.c:2269
 link_path_walk fs/namei.c:2193 [inline]
 path_lookupat+0xb7/0x850 fs/namei.c:2420
 filename_lookup+0x1b1/0x570 fs/namei.c:2454
 user_path_at include/linux/namei.h:60 [inline]
 vfs_statx+0x142/0x390 fs/stat.c:203
 vfs_fstatat fs/stat.c:225 [inline]
 vfs_lstat include/linux/fs.h:3384 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:380
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f4ef87ee335
Code: 69 db 2b 00 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 83 ff 01 48 89 f0 77 30 48 89 c7 48 89 d6 b8 06 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 03 f3 c3 90 48 8b 15 31 db 2b 00 f7 d8 64 89
RSP: 002b:00007ffd133d3fb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000006
RAX: ffffffffffffffda RBX: 00005638ebc3c650 RCX: 00007f4ef87ee335
RDX: 00007ffd133d3ff0 RSI: 00007ffd133d3ff0 RDI: 00005638ebc3b650
RBP: 00007ffd133d40b0 R08: 00007f4ef8aad1d8 R09: 0000000000001010
R10: 00007f4ef8aacb58 R11: 0000000000000246 R12: 00005638ebc3b650
R13: 00005638ebc3b673 R14: 00005638ebc391a1 R15: 00005638ebc391a3

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/06/04 13:57 upstream f88cd3fb9df2 966a236b .config console log report info ci-upstream-kasan-gce-root WARNING: suspicious RCU usage in dput
2021/03/30 02:49 upstream 1e43c377a79f 6a81331a .config console log report info ci-upstream-kasan-gce-selinux-root WARNING: suspicious RCU usage in dput
* Struck through repros no longer work on HEAD.