syzbot


WARNING: suspicious RCU usage in get_counters (2)

Status: fixed on 2021/11/10 00:50
Subsystems: netfilter
[Documentation on labels]
Fix commit: 3066820034b5 rcu: Reject RCU_LOCKDEP_WARN() false positives
First crash: 1088d, last: 1088d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING: suspicious RCU usage in get_counters netfilter 1 1303d 1299d 0/27 auto-closed as invalid on 2021/03/25 10:51

Sample crash report:
=============================
WARNING: suspicious RCU usage
5.13.0-rc7-syzkaller #0 Not tainted
-----------------------------
kernel/sched/core.c:8303 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
1 lock held by syz-executor.1/8478:
 #0: 
ffff8881478c0308
 (
&xt[i].mutex
){+.+.}-{3:3}
, at: xt_find_table_lock+0x18d/0xae0 net/netfilter/x_tables.c:1226

stack backtrace:
CPU: 0 PID: 8478 Comm: syz-executor.1 Not tainted 5.13.0-rc7-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:8303
 get_counters+0x32c/0x5c0 net/ipv4/netfilter/ip_tables.c:765
 do_ipt_get_ctl+0x634/0x9d0 net/ipv4/netfilter/ip_tables.c:805
 nf_getsockopt+0x72/0xd0 net/netfilter/nf_sockopt.c:116
 ip_getsockopt net/ipv4/ip_sockglue.c:1777 [inline]
 ip_getsockopt+0x164/0x1c0 net/ipv4/ip_sockglue.c:1756
 tcp_getsockopt+0x86/0xd0 net/ipv4/tcp.c:4252
 __sys_getsockopt+0x21f/0x5f0 net/socket.c:2148
 __do_sys_getsockopt net/socket.c:2163 [inline]
 __se_sys_getsockopt net/socket.c:2160 [inline]
 __x64_sys_getsockopt+0xba/0x150 net/socket.c:2160
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x467bea
Code: 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:0000000000a9f678 EFLAGS: 00000202
 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000467bea
RDX: 0000000000000041 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000a9f6a0 R08: 0000000000a9f69c R09: 0000000000a9f730
R10: 0000000000a9f700 R11: 0000000000000202 R12: 0000000000a9f700
R13: 0000000000000003 R14: 0000000000a9f69c R15: 00000000005453c0

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/06/27 17:56 upstream 625acffd7ae2 9d2ab5df .config console log report info ci-upstream-kasan-gce WARNING: suspicious RCU usage in get_counters
* Struck through repros no longer work on HEAD.