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: 178d, last: 9h22m
▶ ▼ 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 (3)
Created Duration User Patch Repo Result
2026/04/17 04:51 1m fix candidate upstream error job log
2026/03/17 14:34 1m fix candidate upstream error job log
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.0.17/5939:
 #0: ffffffff8e3d70c8 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x7a4/0x1140 net/core/dev_ioctl.c:769

stack backtrace:
CPU: 1 PID: 5939 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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+0x46b/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+0x1e8/0x6a0 net/core/dev.c:8723
 dev_change_flags+0x7c/0x1a0 net/core/dev.c:8795
 dev_ioctl+0x7b4/0x1140 net/core/dev_ioctl.c:770
 sock_do_ioctl+0x239/0x310 net/socket.c:1234
 sock_ioctl+0x5be/0x7e0 net/socket.c:1341
 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+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1ff5b9e0d9
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:00007ffefeb44b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f1ff5e25fa0 RCX: 00007f1ff5b9e0d9
RDX: 0000200000002280 RSI: 0000000000008914 RDI: 0000000000000004
RBP: 00007f1ff5c35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1ff5e25fac R14: 00007f1ff5e25fa0 R15: 00007f1ff5e25fa0
 </TASK>
mac80211_hwsim hwsim4 syzkaller0: entered promiscuous mode
mac80211_hwsim hwsim4 syzkaller0: entered allmulticast mode

Crashes (2931):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/08 03:42 linux-6.6.y 6436c12a2ced e4ef95d6 .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
2026/05/27 10:01 linux-6.6.y 0a40c6fbd105 2b01f00e .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
2026/02/16 03:42 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 23:10 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
2026/02/15 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
2026/08/08 11:07 linux-6.6.y 6436c12a2ced 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/08 07:08 linux-6.6.y 6436c12a2ced 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/07 22:16 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/07 19:49 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/07 19:49 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/07 12:53 linux-6.6.y 6436c12a2ced e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/07 06:40 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/07 05:28 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/07 02:09 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/07 01:52 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/06 22:49 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/06 21:19 linux-6.6.y 80dfb0405055 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/06 17:55 linux-6.6.y aa0e49877a2e c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/06 16:47 linux-6.6.y aa0e49877a2e c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/06 04:41 linux-6.6.y aa0e49877a2e cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/06 02:37 linux-6.6.y aa0e49877a2e cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/05 23:03 linux-6.6.y aa0e49877a2e cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/05 21:52 linux-6.6.y aa0e49877a2e cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/05 13:58 linux-6.6.y aa0e49877a2e 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/05 10:24 linux-6.6.y aa0e49877a2e 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/05 08:53 linux-6.6.y aa0e49877a2e 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/05 05:50 linux-6.6.y aa0e49877a2e 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/04 18:37 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/04 18:20 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/04 15:04 linux-6.6.y aa0e49877a2e d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/04 07:46 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/04 04:55 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/04 02:37 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/04 01:49 linux-6.6.y aa0e49877a2e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/03 20:37 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/03 19:02 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/03 17:39 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/03 13:32 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/03 13:32 linux-6.6.y aa0e49877a2e 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/03 06:43 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/02 23:50 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/02 14:03 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/02 00:09 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/01 19:17 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/01 17:28 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/01 12:33 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/01 10:45 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/01 08:19 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/01 08:13 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING: suspicious RCU usage in ieee80211_check_concurrent_iface
2026/08/01 05:26 linux-6.6.y a1153c0deb44 e611ffe1 .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.