CVE-2026-98073

In the Linux kernel, the following vulnerability has been resolved:

net: Remove conflicting altnames for dying netns in dev change net namespace().

syzbot reported the warning in cfg80211 pernet exit(). [0]

The repro does the following:

Since commit 7663d522099e ("net: check for altname conflicts when changing netdev's netns"), cfg80211 switch netns() and cfg802154 switch netns() fail if init net has a device with the conflicting altname.

default device exit net() had the same issue and commit d09486a04f5d ("net: fix removing a namespace with conflicting altnames") fixed it.

cfg80211 pernet exit() and cfg802154 pernet exit() need the same fix.

Let's generalise the fix by removing conflicting altnames for dying netns in dev change net namespace().

[0]: cfg80211 switch netns(rdev, &init net) WARNING: net/wireless/core.c:1871 at cfg80211 pernet exit+0xd5/0x120 net/wireless/core.c:1871, CPU#1: kworker/u8:9/1160 Modules linked in: CPU: 1 UID: 0 PID: 1160 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: netns cleanup net RIP: 0010:cfg80211 pernet exit+0xd5/0x120 net/wireless/core.c:1871 Code: e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 b4 ef 0e f7 4d 8b 36 49 81 fe 20 10 4a 90 74 12 e8 03 3d 9f f6 eb 85 e8 fc 3c 9f f6 90 <0f> 0b 90 eb cc e8 f1 3c 9f f6 eb 05 e8 ea 3c 9f f6 5b 41 5c 41 5e RSP: 0018:ffffc900057a78f0 EFLAGS: 00010293 RAX: ffffffff8b287154 RBX: ffff88807ba72780 RCX: ffff8880213e8000 RDX: 0000000000000000 RSI: 00000000ffffffef RDI: 0000000000000000 RBP: 00000000ffffffef R08: ffffffff9024cc67 R09: 0000000000000000 R10: fffff52000af4eb0 R11: fffffbfff204998d R12: dffffc0000000000 R13: ffffffff904a1080 R14: ffff888144ed0008 R15: ffff888144ed0e20 FS: 0000000000000000(0000) GS:ffff888124de6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005642de0a8a70 CR3: 000000007a40c000 CR4: 00000000003526f0 Call Trace: ops exit list net/core/net namespace.c:200 [inline] ops undo list+0x43d/0x8d0 net/core/net namespace.c:253 cleanup net+0x572/0x810 net/core/net namespace.c:706 process one work kernel/workqueue.c:3387 [inline] process scheduled works+0xc3d/0x1630 kernel/workqueue.c:3470 worker thread+0xa47/0xfb0 kernel/workqueue.c:3551 kthread+0x38b/0x480 kernel/kthread.c:436 ret from fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret from fork asm+0x1a/0x30 arch/x86/entry/entry 64.S:245