[syzbot] [wireless?] WARNING in ieee80211_encrypt_tx_skb

[syzbot] [wireless?] WARNING in ieee80211_encrypt_tx_skb

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    61c03dfde854 Merge tag 'ntfs-for-7.2-rc3' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=116470b9580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=20c9876b0f77b546
dashboard link: https://syzkaller.appspot.com/bug?extid=b6ce23950fd636e6efb6
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16b85432580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=162e20b9580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-61c03dfd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e06f2aec094f/vmlinux-61c03dfd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a85168c67732/bzImage-61c03dfd.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b6ce23950fd636e6efb6@syzkaller.appspotmail.com

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fb87e825fac R14: 00007fb87e825fa0 R15: 00007fb87e825fa0
 </TASK>
------------[ cut here ]------------
res != TX_CONTINUE
WARNING: net/mac80211/tx.c:5460 at ieee80211_encrypt_tx_skb+0x3e4/0x3f0 net/mac80211/tx.c:5460, CPU#0: syz.0.17/5534
Modules linked in:
CPU: 0 UID: 0 PID: 5534 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:ieee80211_encrypt_tx_skb+0x3e4/0x3f0 net/mac80211/tx.c:5460
Code: ff ff ff e8 9e 1a 7a f6 90 0f 0b 90 e9 0b ff ff ff e8 90 1a 7a f6 90 0f 0b 90 bb ea ff ff ff e9 20 ff ff ff e8 7d 1a 7a f6 90 <0f> 0b 90 eb eb e8 d2 bb 84 00 66 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003526a20 EFLAGS: 00010293
RAX: ffffffff8b4c6813 RBX: 0000000000000000 RCX: ffff88803a6f0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003526b90 R08: ffff8880129723cf R09: 0000000000000000
R10: ffff8880129723c0 R11: ffffed100252e47a R12: ffffc90003526a68
R13: 1ffff920006a4d48 R14: dffffc0000000000 R15: 0000000000000001
FS:  00005555940ec500(0000) GS:ffff88808c54d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003700 CR3: 0000000012968000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 mac80211_hwsim_tx+0x1de/0x2500 drivers/net/wireless/virtual/mac80211_hwsim_main.c:2116
 ieee80211_hwsim_wake_tx_queue+0xd4/0x150 drivers/net/wireless/virtual/mac80211_hwsim_main.c:2291
 drv_wake_tx_queue net/mac80211/driver-ops.h:1394 [inline]
 schedule_and_wake_txq net/mac80211/driver-ops.h:1401 [inline]
 ieee80211_queue_skb+0x1923/0x22c0 net/mac80211/tx.c:1674
 __ieee80211_xmit_fast+0x8ea/0x2160 net/mac80211/tx.c:3785
 ieee80211_xmit_fast net/mac80211/tx.c:3853 [inline]
 __ieee80211_subif_start_xmit+0x12af/0x1690 net/mac80211/tx.c:4367
 ieee80211_tx_control_port+0xaba/0xcd0 net/mac80211/tx.c:6592
 rdev_tx_control_port net/wireless/rdev-ops.h:783 [inline]
 nl80211_tx_control_port+0x604/0x990 net/wireless/nl80211.c:18403
 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0x54e/0x850 net/socket.c:2684
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
 __sys_sendmsg net/socket.c:2770 [inline]
 __do_sys_sendmsg net/socket.c:2775 [inline]
 __se_sys_sendmsg net/socket.c:2773 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb87e59de59
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:00007ffca021cc48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb87e825fa0 RCX: 00007fb87e59de59
RDX: 0000000000000800 RSI: 0000200000003700 RDI: 0000000000000003
RBP: 00007ffca021ccb0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fb87e825fac R14: 00007fb87e825fa0 R15: 00007fb87e825fa0
 </TASK>


---
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Forwarded: [PATCH] mac80211: debug print key cipher in ieee80211_tx_h_encrypt

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: [PATCH] mac80211: debug print key cipher in ieee80211_tx_h_encrypt
Author: kartikey406@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

Reported-by: syzbot+b6ce23950fd636e6efb6@syzkaller.appspotmail.com
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
---
 net/mac80211/tx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index c13b209fad47..5fb2fa7adf07 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1045,6 +1045,9 @@ ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
 static ieee80211_tx_result debug_noinline
 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
 {
+	if (tx->key)
+		printk("key cipher = 0x%x\n",
+		       tx->key->conf.cipher);
 	if (!tx->key)
 		return TX_CONTINUE;
 
-- 
2.43.0

Forwarded: [PATCH] mac80211: don't encrypt pre-auth (ETH_P_PREAUTH) frames

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: [PATCH] mac80211: don't encrypt pre-auth (ETH_P_PREAUTH) frames
Author: kartikey406@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master



Pre-authentication frames (ETH_P_PREAUTH, 0x88C7) are sent before
the authentication handshake completes with the target AP, so no
encryption key exists for them yet. Unlike normal EAPOL frames
(ETH_P_8021X, 0x888E) which are registered as the control port
protocol, pre-auth frames are not recognized as control port frames,
causing the kernel to incorrectly assign the current AP's key and
attempt encryption, resulting in a WARN_ON in ieee80211_encrypt_tx_skb
when the cipher is not handled.

Fix this by setting IEEE80211_TX_INTFL_DONT_ENCRYPT for pre-auth
frames in ieee80211_tx_h_check_control_port_protocol(), so that
key selection skips them and they are sent unencrypted as intended.

Reported-by: syzbot+b6ce23950fd636e6efb6@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b6ce23950fd636e6efb6
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
---
 net/mac80211/tx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index c13b209fad47..b3acfd69380f 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -557,6 +557,9 @@ ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
 		info->flags |= IEEE80211_TX_CTL_USE_MINRATE;
 	}
 
+	if (tx->skb->protocol == htons(ETH_P_PREAUTH))
+		info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
+
 	return TX_CONTINUE;
 }
 
-- 
2.43.0

Forwarded:

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: 
Author: nogikh@google.com

Let's check if the command works.

#syz test

Forwarded: Re:

[syzbot]

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linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: Re:
Author: nogikh@google.com

Let's check again

#syz test

On Wed, Jul 15, 2026 at 10:27 PM Aleksandr Nogikh <nogikh@google.com> wrote:
>
> Let's check if the command works.
>
> #syz test