syzbot


WARNING: suspicious RCU usage in get_timespec64

Status: fixed on 2021/11/10 00:50
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+88e4f02896967fe1ab0d@syzkaller.appspotmail.com
Fix commit: 3066820034b5 rcu: Reject RCU_LOCKDEP_WARN() false positives
First crash: 1176d, last: 1123d
Duplicate bugs (1)
duplicates (1):
Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
WARNING: suspicious RCU usage in __ext4_handle_dirty_metadata ext4 1 1176d 1172d 0/27 closed as dup on 2021/04/05 00:08
Discussions (9)
Title Replies (including bot) Last reply
[PATCH 5.10 000/243] 5.10.52-rc1 review 254 (254) 2021/07/21 15:19
[PATCH 5.13 000/351] 5.13.4-rc1 review 353 (353) 2021/07/19 19:32
[PATCH 5.12 000/292] 5.12.19-rc1 review 294 (294) 2021/07/19 17:28
[PATCH AUTOSEL 5.13 001/114] leds: tlc591xx: fix return value check in tlc591xx_probe() 81 (81) 2021/07/18 00:44
[PATCH AUTOSEL 5.10 01/93] leds: tlc591xx: fix return value check in tlc591xx_probe() 95 (95) 2021/07/12 21:48
[PATCH AUTOSEL 5.12 001/104] leds: tlc591xx: fix return value check in tlc591xx_probe() 105 (105) 2021/07/10 05:16
[tip: core/rcu] rcu: Reject RCU_LOCKDEP_WARN() false positives 1 (1) 2021/06/30 13:47
[PATCH tip/core/rcu 0/19] Miscellaneous fixes for v5.14 20 (20) 2021/05/11 22:53
[syzbot] WARNING: suspicious RCU usage in get_timespec64 10 (11) 2021/04/05 23:42

Sample crash report:
=============================
WARNING: suspicious RCU usage
5.13.0-rc2-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 syz-executor.3/13710.

stack backtrace:
CPU: 0 PID: 13710 Comm: syz-executor.3 Not tainted 5.13.0-rc2-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
 __might_fault+0x6e/0x180 mm/memory.c:5067
 _copy_from_user+0x27/0x180 lib/usercopy.c:13
 copy_from_user include/linux/uaccess.h:192 [inline]
 get_timespec64+0x75/0x220 kernel/time/time.c:787
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1257 [inline]
 __se_sys_clock_nanosleep kernel/time/posix-timers.c:1245 [inline]
 __x64_sys_clock_nanosleep+0x1bb/0x430 kernel/time/posix-timers.c:1245
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x48a7a1
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f
RSP: 002b:00007ffc76666ad0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000000000000016a RCX: 000000000048a7a1
RDX: 00007ffc76666b10 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc76666bac R08: 0000000000000000 R09: 00007ffc76752080
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 000000000005ea86 R14: 0000000000000001 R15: 00007ffc76666c10

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/05/23 19:58 upstream 4d7620341eda 3c7fef33 .config console log report info ci-upstream-kasan-gce-selinux-root WARNING: suspicious RCU usage in get_timespec64
2021/03/31 18:56 upstream 5e46d1b78a03 6a81331a .config console log report info ci-upstream-kasan-gce-selinux-root WARNING: suspicious RCU usage in get_timespec64
2021/05/06 04:18 linux-next 23c498428c14 06c27ff5 .config console log report info ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in get_timespec64
* Struck through repros no longer work on HEAD.