syzbot


WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface

Status: upstream: reported C repro on 2026/02/11 18:46
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+95df812296710ce46e07@syzkaller.appspotmail.com
First crash: 4d03h, last: 4h02m
Bug presence (2)
Date Name Commit Repro Result
2026/02/14 linux-6.6.y (ToT) 1b4ef5214f17 C [report] WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/14 upstream (ToT) 770aaedb461a C Didn't crash
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2026/02/15 14:22 12m fix candidate upstream error job log

Sample crash report:
=============================
WARNING: suspicious RCU usage
syzkaller #0 Not tainted
-----------------------------
net/mac80211/iface.c:378 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz.0.17/5930:
 #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x7a4/0x1140 net/core/dev_ioctl.c:769

stack backtrace:
CPU: 1 PID: 5930 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 lockdep_rcu_suspicious+0x1e1/0x300 kernel/locking/lockdep.c:6731
 ieee80211_check_concurrent_iface+0x475/0x950 net/mac80211/iface.c:378
 ieee80211_open+0xc1/0x200 net/mac80211/iface.c:466
 __dev_open+0x2cb/0x430 net/core/dev.c:1519
 __dev_change_flags+0x211/0x6a0 net/core/dev.c:8698
 dev_change_flags+0x88/0x1a0 net/core/dev.c:8770
 dev_ioctl+0x7b4/0x1140 net/core/dev_ioctl.c:770
 sock_do_ioctl+0x239/0x310 net/socket.c:1233
 sock_ioctl+0x5ba/0x7e0 net/socket.c:1340
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fede5b9bf79
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe845819a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fede5e15fa0 RCX: 00007fede5b9bf79
RDX: 00002000000000c0 RSI: 0000000000008914 RDI: 0000000000000005
RBP: 00007fede5c327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fede5e15fac R14: 00007fede5e15fa0 R15: 00007fede5e15fa0
 </TASK>
mac80211_hwsim hwsim5 syzkaller0: entered promiscuous mode
mac80211_hwsim hwsim5 syzkaller0: entered allmulticast mode

Crashes (95):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/15 18:34 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/15 13:52 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/15 09:12 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/15 04:33 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/14 23:54 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/14 18:47 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/14 14:10 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/14 09:17 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/15 15:47 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/15 15:27 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/15 10:20 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/14 14:42 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/14 11:18 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 23:20 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 22:14 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 20:52 linux-6.6.y 1b4ef5214f17 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 12:05 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 12:04 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 12:03 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 11:43 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 08:38 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 08:37 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 08:36 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 08:27 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 08:25 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 08:25 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 08:22 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 08:21 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 03:42 linux-6.6.y 1b4ef5214f17 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/13 02:10 linux-6.6.y 1b4ef5214f17 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/12 22:11 linux-6.6.y 1b4ef5214f17 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/12 22:11 linux-6.6.y 1b4ef5214f17 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/12 06:27 linux-6.6.y 1b4ef5214f17 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/12 06:19 linux-6.6.y 1b4ef5214f17 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/12 05:53 linux-6.6.y 1b4ef5214f17 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/12 05:49 linux-6.6.y 1b4ef5214f17 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/12 05:47 linux-6.6.y 1b4ef5214f17 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:57 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:57 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:55 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:55 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:54 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:52 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:51 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:51 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:49 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:49 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:47 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:44 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 23:43 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/02/11 18:46 linux-6.6.y 1b4ef5214f17 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
* Struck through repros no longer work on HEAD.