Subject: Re: [PATCH net v3] xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()

From: Pedro Falcato <[email-masked]>
Date: Mon, 25 May 2026 11:22:32 +0100

On Fri, May 22, 2026 at 11:25:04AM -0300, Takao Sato wrote:
> iptfs_consume_frags() transfers paged fragments from one socket buffer
> to another but fails to propagate the SKBFL_SHARED_FRAG flag. This is
> the same class of bug that was fixed in skb_try_coalesce() for
> CVE-2026-46300: when fragments backed by read-only page-cache pages are
> merged, the marker indicating their shared nature must be preserved so
> that ESP can decide correctly whether in-place encryption is safe.
> 
> Apply the same two-line fix used in skb_try_coalesce() to
> iptfs_consume_frags().
> 
> Fixes: b96ba312e21c ("xfrm: iptfs: share page fragments of inner packets")
> Cc: [email-masked] # 6.8+

Why? This code seems to have only been introduced in 6.14, aka the only LTS
version this applies to is 6.18. Typo?

-- 
Pedro