From 1272ce87fa017ca4cf32920764d879656b7a005a Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 10 Jan 2017 12:24:01 -0800 Subject: gro: Enter slow-path if there is no tailroom The GRO path has a fast-path where we avoid calling pskb_may_pull and pskb_expand by directly accessing frag0. However, this should only be done if we have enough tailroom in the skb as otherwise we'll have to expand it later anyway. This patch adds the check by capping frag0_len with the skb tailroom. Fixes: cb18978cbf45 ("gro: Open-code final pskb_may_pull") Reported-by: Slava Shwartsman Signed-off-by: Herbert Xu Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 8db5a0b4b520..88d2907ca2cd 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4441,7 +4441,8 @@ static void skb_gro_reset_offset(struct sk_buff *skb) pinfo->nr_frags && !PageHighMem(skb_frag_page(frag0))) { NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0); - NAPI_GRO_CB(skb)->frag0_len = skb_frag_size(frag0); + NAPI_GRO_CB(skb)->frag0_len = min(skb_frag_size(frag0), + skb->end - skb->tail); } } -- cgit From 7cfd5fd5a9813f1430290d20c0fead9b4582a307 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 10 Jan 2017 19:52:43 -0800 Subject: gro: use min_t() in skb_gro_reset_offset() On 32bit arches, (skb->end - skb->data) is not 'unsigned int', so we shall use min_t() instead of min() to avoid a compiler error. Fixes: 1272ce87fa01 ("gro: Enter slow-path if there is no tailroom") Reported-by: kernel test robot Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 88d2907ca2cd..07b307b0b414 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4441,8 +4441,9 @@ static void skb_gro_reset_offset(struct sk_buff *skb) pinfo->nr_frags && !PageHighMem(skb_frag_page(frag0))) { NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0); - NAPI_GRO_CB(skb)->frag0_len = min(skb_frag_size(frag0), - skb->end - skb->tail); + NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int, + skb_frag_size(frag0), + skb->end - skb->tail); } } -- cgit