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: stable@vger.kernel.org # 6.14+ Signed-off-by: Takao Sato --- Changes since v3: - Corrected Cc: stable tag from "# 6.8+" to "# 6.14+". IPTFS was introduced in v6.14, so earlier stable branches do not need this fix. Pointed out by Pedro Falcato. Changes since v2: - Removed security impact paragraph from commit message as requested by Steffen Klassert. net/xfrm/xfrm_iptfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c index 97bc979e5..4db85e158 100644 --- a/net/xfrm/xfrm_iptfs.c +++ b/net/xfrm/xfrm_iptfs.c @@ -2168,6 +2168,8 @@ static void iptfs_consume_frags(struct sk_buff *to, struct sk_buff *from) memcpy(&toi->frags[toi->nr_frags], fromi->frags, sizeof(fromi->frags[0]) * fromi->nr_frags); toi->nr_frags += fromi->nr_frags; + if (fromi->nr_frags) + toi->flags |= fromi->flags & SKBFL_SHARED_FRAG; fromi->nr_frags = 0; from->data_len = 0; from->len = 0; -- 2.43.0