WARNING in mac80211_hwsim_tx

Status: upstream: reported on 2026/10/04 18:20
Reported-by: syzbot+72ba7f38dd4a61d47ea1@syzkaller.appspotmail.com
First crash: 39d, last: 15d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in mac80211_hwsim_tx (2) prio:normal wireless -1 syz, C error 540 3h54m 186d 26/29 upstream: reported C repro on 2026/05/10 21:02
linux-6.1 WARNING in mac80211_hwsim_tx -1 1 167d 167d 0/3 auto-obsoleted due to no activity on 2026/09/06 17:05
upstream WARNING in mac80211_hwsim_tx wireless -1 44 593d 695d 0/29 auto-obsoleted due to no activity on 2025/06/07 07:17

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 7448 at drivers/net/wireless/virtual/mac80211_hwsim.c:240 hwsim_check_sta_magic drivers/net/wireless/virtual/mac80211_hwsim.c:240 [inline]
WARNING: CPU: 1 PID: 7448 at drivers/net/wireless/virtual/mac80211_hwsim.c:240 mac80211_hwsim_tx+0x1bdd/0x26e0 drivers/net/wireless/virtual/mac80211_hwsim.c:2002
Modules linked in:
CPU: 1 PID: 7448 Comm: syz.3.426 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:hwsim_check_sta_magic drivers/net/wireless/virtual/mac80211_hwsim.c:240 [inline]
RIP: 0010:mac80211_hwsim_tx+0x1bdd/0x26e0 drivers/net/wireless/virtual/mac80211_hwsim.c:2002
Code: 85 9a 0a 00 00 45 0f b6 8f f4 03 00 00 48 c7 c7 00 ef 84 8b 4c 89 fe 89 ea e8 6f 6f 14 fb 0f 0b e9 70 f1 ff ff e8 43 c1 4a fb <0f> 0b e9 de f1 ff ff e8 37 c1 4a fb 0f 0b e9 22 fa ff ff e8 2b c1
RSP: 0018:ffffc90003b26ee8 EFLAGS: 00010287
RAX: ffffffff863d129d RBX: 1ffff1100ba2b920 RCX: 0000000000080000
RDX: ffffc9000de85000 RSI: 0000000000000826 RDI: 0000000000000827
RBP: 0000000000000000 R08: ffff88805d15c8cf R09: 0000000000000000
R10: ffff88805d15c8c0 R11: ffffed100ba2b91a R12: 1ffff92000764e10
R13: 0000000000000000 R14: ffff88805d15c900 R15: ffff88807828d160
FS:  00007f7fcb12d6c0(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c302607 CR3: 0000000068935000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 drv_tx net/mac80211/driver-ops.h:37 [inline]
 ieee80211_tx_frags+0x3d5/0x880 net/mac80211/tx.c:1750
 __ieee80211_xmit_fast+0xa96/0x2100 net/mac80211/tx.c:3764
 ieee80211_mesh_xmit_fast+0xb03/0xf00 net/mac80211/mesh.c:856
 __ieee80211_subif_start_xmit+0x785/0x1620 net/mac80211/tx.c:4311
 ieee80211_subif_start_xmit+0xf2/0x570 net/mac80211/tx.c:4553
 __netdev_start_xmit include/linux/netdevice.h:5003 [inline]
 netdev_start_xmit include/linux/netdevice.h:5017 [inline]
 xmit_one net/core/dev.c:3671 [inline]
 dev_hard_start_xmit+0x269/0x790 net/core/dev.c:3687
 __dev_queue_xmit+0x1d1e/0x3a30 net/core/dev.c:4518
 packet_snd net/packet/af_packet.c:3171 [inline]
 packet_sendmsg+0x38a0/0x49d0 net/packet/af_packet.c:3203
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x4a9/0x6b0 net/socket.c:2201
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2209
 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: 0033:0x7f7fca19f559
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:00007f7fcb12d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f7fca425fa0 RCX: 00007f7fca19f559
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f7fca236b20 R08: 0000200000000540 R09: 0000000000000014
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7fca426038 R14: 00007f7fca425fa0 R15: 00007ffd73dadf18
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/28 20:25 linux-6.6.y 0aebf2870d53 858db2ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in mac80211_hwsim_tx
2026/10/24 15:56 linux-6.6.y 0aebf2870d53 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in mac80211_hwsim_tx
2026/10/24 15:55 linux-6.6.y 0aebf2870d53 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in mac80211_hwsim_tx
2026/10/04 18:20 linux-6.6.y a91a6aa9253c 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in mac80211_hwsim_tx
* Struck through repros no longer work on HEAD.