CVE-2026-31515

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

af_key: validate families in pfkey_send_migrate()

syzbot was able to trigger a crash in skb_put() [1]

Issue is that pfkey_send_migrate() does not check old/new families,

and that set_ipsecrequest() @family argument was truncated,

thus possibly overfilling the skb.

Validate families early, do not wait set_ipsecrequest().

[1]

skbuff: skb_over_panic: text:ffffffff8a752120 len:392 put:16 head:ffff88802a4ad040 data:ffff88802a4ad040 tail:0x188 end:0x180 dev:<NULL>

kernel BUG at net/core/skbuff.c:214 !

Call Trace:

<TASK>

skb_over_panic net/core/skbuff.c:219 [inline]

skb_put+0x159/0x210 net/core/skbuff.c:2655

skb_put_zero include/linux/skbuff.h:2788 [inline]

set_ipsecrequest net/key/af_key.c:3532 [inline]

pfkey_send_migrate+0x1270/0x2e50 net/key/af_key.c:3636

km_migrate+0x155/0x260 net/xfrm/xfrm_state.c:2848

xfrm_migrate+0x2140/0x2450 net/xfrm/xfrm_policy.c:4705

xfrm_do_migrate+0x8ff/0xaa0 net/xfrm/xfrm_user.c:3150