CVE-2026-68426

Summary

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

xfrm: fix stale skb->prev after async crypto steals a GSO segment

skb_gso_segment() leaves the segment list head with ->prev pointing at the last segment, an invariant validate_xmit_skb_list() relies on when it sets its tail pointer (tail = skb->prev).

When validate_xmit_xfrm() walks a GSO list and some segments are stolen by async crypto (->xmit() returns -EINPROGRESS), those segments are unlinked from the list but the head ->prev is never updated. If the last segment is the one stolen, the returned head still has ->prev pointing at it, even though it is now owned by the crypto engine and may be freed. validate_xmit_skb_list() later does tail->next = skb, writing through that stale pointer – a use-after-free.

Repoint skb->prev at the last retained segment before returning.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxf53c723902d1ac5f0b0a11d7c9dcbff748dde74e < 33e1b0d25ca0d2818c635ff80e6aa0d295e08a98affected
LinuxLinuxf53c723902d1ac5f0b0a11d7c9dcbff748dde74e < bbca7cc3b2b4b10afbfee99b81d9ee78f5423046affected
LinuxLinuxf53c723902d1ac5f0b0a11d7c9dcbff748dde74e < 3f4c3919baf0944ad96580467c302bc6c7758b00affected
LinuxLinux4.16affected
LinuxLinux0 < 4.16unaffected
LinuxLinux6.18.42 <= 6.18.*unaffected
LinuxLinux7.1.6 <= 7.1.*unaffected
LinuxLinux7.2-rc4 <= *unaffected

Weaknesses

References