From 1e6d45378b272fe2f1fce48ed89d6eaa415c00c2 Mon Sep 17 00:00:00 2001 From: Jingguo Tan Date: Mon, 18 May 2026 17:06:48 +0800 Subject: [PATCH ipsec v2] xfrm: esp: restore combined single-frag length gate The ESP out-of-place fast path appends the trailer in esp_output_head() before esp_output_tail() allocates the destination page frag. The head-side gate currently checks skb->data_len and tailen separately, but the tail code allocates a single destination frag from the combined post-trailer skb->data_len. Reject the page-frag fast path when the combined aligned length exceeds a page. Otherwise skb_page_frag_refill() may fall back to a single page while the destination sg still spans the combined skb->data_len. Restore this combined-length page gate for both IPv4 and IPv6. Fixes: 5bd8baab087d ("esp: limit skb_page_frag_refill use to a single page") Cc: stable@vger.kernel.org Signed-off-by: Lin Ma Signed-off-by: Chenyuan Mi Signed-off-by: Jingguo Tan --- Changes in v2: - Use the ipsec tree subject prefix. - Clarify that esp_output_tail() allocates after esp_output_head() appends tailen. - Avoid shadowing the existing allocsize variable. - v1: https://lore.kernel.org/netdev/ag7kxJ39XQaVY1Mb@krikkit/T/#t net/ipv4/esp4.c | 4 ++-- net/ipv6/esp6.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 6a5febbdbee49..c62dfe049ee7 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -419,8 +419,8 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info * return err; } - if (ALIGN(tailen, L1_CACHE_BYTES) > PAGE_SIZE || - ALIGN(skb->data_len, L1_CACHE_BYTES) > PAGE_SIZE) + if (ALIGN(skb->data_len + tailen, L1_CACHE_BYTES) > + PAGE_SIZE) goto cow; if (!skb_cloned(skb)) { diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index 9c06c5a1419dc..2516a4dc6d78 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -448,8 +448,8 @@ int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info return err; } - if (ALIGN(tailen, L1_CACHE_BYTES) > PAGE_SIZE || - ALIGN(skb->data_len, L1_CACHE_BYTES) > PAGE_SIZE) + if (ALIGN(skb->data_len + tailen, L1_CACHE_BYTES) > + PAGE_SIZE) goto cow; if (!skb_cloned(skb)) { -- 2.43.0