From a432934a30679c0e3c47b87f13e4901bc1a3fc03 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Fri, 30 Jul 2021 18:30:53 +0200 Subject: [PATCH] sk_buff: avoid potentially clearing 'slow_gro' field If skb_dst_set_noref() is invoked with a NULL dst, the 'slow_gro' field is cleared, too. That could lead to wrong behavior if the skb later enters the GRO stage. Fix the potential issue replacing preserving a non-zero value of the 'slow_gro' field. Additionally, fix a comment typo. Reported-by: Sabrina Dubroca Reported-by: Jakub Kicinski Fixes: 8a886b142bd0 ("sk_buff: track dst status in slow_gro") Signed-off-by: Paolo Abeni Link: https://lore.kernel.org/r/aa42529252dc8bb02bd42e8629427040d1058537.1627662501.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski --- include/linux/skbuff.h | 2 +- net/core/dev.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index b1e5bbfcc926f..2bcdc8cd38be8 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1009,7 +1009,7 @@ static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) { WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); - skb->slow_gro = !!dst; + skb->slow_gro |= !!dst; skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF; } diff --git a/net/core/dev.c b/net/core/dev.c index b51e41d0a7fe2..64e1a5f63f93b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6022,7 +6022,7 @@ static void gro_list_prepare(const struct list_head *head, skb_mac_header(skb), maclen); - /* in most common scenarions _state is 0 + /* in most common scenarions 'slow_gro' is 0 * otherwise we are already on some slower paths * either skip all the infrequent tests altogether or * avoid trying too hard to skip each of them individually