syzbot


WARNING: suspicious RCU usage in wg_ratelimiter_gc_entries

Status: fixed on 2021/11/10 00:50
Reported-by: syzbot+@syzkaller.appspotmail.com
Fix commit: 3066820034b5 rcu: Reject RCU_LOCKDEP_WARN() false positives
First crash: 544d, last: 469d

Sample crash report:
=============================
WARNING: suspicious RCU usage
5.13.0-rc5-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
2 locks held by kworker/1:1/27:
 #0: 
ffff888011070d38
 (
(wq_completion)events_power_efficient
){+.+.}-{0:0}
, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
, at: set_work_data kernel/workqueue.c:617 [inline]
, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2247
 #1: 
ffffc90000e37da8
 (
(gc_work).work
){+.+.}-{0:0}
, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2251

stack backtrace:
CPU: 1 PID: 27 Comm: kworker/1:1 Not tainted 5.13.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
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
 wg_ratelimiter_gc_entries+0x2f1/0x430 drivers/net/wireguard/ratelimiter.c:78
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2276
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2422
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Crashes (5):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2021/06/12 11:11 upstream f21b807c3cf8 1ba81399 .config log report info WARNING: suspicious RCU usage in wg_ratelimiter_gc_entries
ci-upstream-kasan-gce-selinux-root 2021/05/25 21:28 upstream a050a6d2b7e8 93d3a9f6 .config log report info WARNING: suspicious RCU usage in wg_ratelimiter_gc_entries
ci-upstream-kasan-gce-root 2021/03/29 04:48 upstream 81b1d39fd39a a8529b82 .config log report info WARNING: suspicious RCU usage in wg_ratelimiter_gc_entries
ci-upstream-kasan-gce-386 2021/05/31 17:42 upstream 8124c8a6b353 032639db .config log report info WARNING: suspicious RCU usage in wg_ratelimiter_gc_entries
ci-upstream-kasan-gce-386 2021/04/16 20:13 upstream 2f7b98d1e55c 7e2b734b .config log report info WARNING: suspicious RCU usage in wg_ratelimiter_gc_entries
* Struck through repros no longer work on HEAD.