Patch "gro: avoid checking for a failed search" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    gro: avoid checking for a failed search

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     gro-avoid-checking-for-a-failed-search.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b41d00312d790b327a2d71ce796ee84ba56140be
Author: Richard Gobert <richardbgobert@xxxxxxxxx>
Date:   Tue Nov 8 13:33:28 2022 +0100

    gro: avoid checking for a failed search
    
    [ Upstream commit e081ecf084d31809242fb0b9f35484d5fb3a161a ]
    
    After searching for a protocol handler in dev_gro_receive, checking for
    failure is redundant. Skip the failure code after finding the
    corresponding handler.
    
    Suggested-by: Eric Dumazet <edumazet@xxxxxxxxxx>
    Signed-off-by: Richard Gobert <richardbgobert@xxxxxxxxx>
    Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20221108123320.GA59373@debian
    Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
    Stable-dep-of: 7871f54e3dee ("gro: take care of DODGY packets")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/core/gro.c b/net/core/gro.c
index bc9451743307..8e0fe85a647d 100644
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -489,45 +489,45 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(ptype, head, list) {
-		if (ptype->type != type || !ptype->callbacks.gro_receive)
-			continue;
-
-		skb_set_network_header(skb, skb_gro_offset(skb));
-		skb_reset_mac_len(skb);
-		BUILD_BUG_ON(sizeof_field(struct napi_gro_cb, zeroed) != sizeof(u32));
-		BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct napi_gro_cb, zeroed),
-					 sizeof(u32))); /* Avoid slow unaligned acc */
-		*(u32 *)&NAPI_GRO_CB(skb)->zeroed = 0;
-		NAPI_GRO_CB(skb)->flush = skb_has_frag_list(skb);
-		NAPI_GRO_CB(skb)->is_atomic = 1;
-		NAPI_GRO_CB(skb)->count = 1;
-		if (unlikely(skb_is_gso(skb))) {
-			NAPI_GRO_CB(skb)->count = skb_shinfo(skb)->gso_segs;
-			/* Only support TCP at the moment. */
-			if (!skb_is_gso_tcp(skb))
-				NAPI_GRO_CB(skb)->flush = 1;
-		}
-
-		/* Setup for GRO checksum validation */
-		switch (skb->ip_summed) {
-		case CHECKSUM_COMPLETE:
-			NAPI_GRO_CB(skb)->csum = skb->csum;
-			NAPI_GRO_CB(skb)->csum_valid = 1;
-			break;
-		case CHECKSUM_UNNECESSARY:
-			NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
-			break;
-		}
+		if (ptype->type == type && ptype->callbacks.gro_receive)
+			goto found_ptype;
+	}
+	rcu_read_unlock();
+	goto normal;
+
+found_ptype:
+	skb_set_network_header(skb, skb_gro_offset(skb));
+	skb_reset_mac_len(skb);
+	BUILD_BUG_ON(sizeof_field(struct napi_gro_cb, zeroed) != sizeof(u32));
+	BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct napi_gro_cb, zeroed),
+					sizeof(u32))); /* Avoid slow unaligned acc */
+	*(u32 *)&NAPI_GRO_CB(skb)->zeroed = 0;
+	NAPI_GRO_CB(skb)->flush = skb_has_frag_list(skb);
+	NAPI_GRO_CB(skb)->is_atomic = 1;
+	NAPI_GRO_CB(skb)->count = 1;
+	if (unlikely(skb_is_gso(skb))) {
+		NAPI_GRO_CB(skb)->count = skb_shinfo(skb)->gso_segs;
+		/* Only support TCP at the moment. */
+		if (!skb_is_gso_tcp(skb))
+			NAPI_GRO_CB(skb)->flush = 1;
+	}
 
-		pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive,
-					ipv6_gro_receive, inet_gro_receive,
-					&gro_list->list, skb);
+	/* Setup for GRO checksum validation */
+	switch (skb->ip_summed) {
+	case CHECKSUM_COMPLETE:
+		NAPI_GRO_CB(skb)->csum = skb->csum;
+		NAPI_GRO_CB(skb)->csum_valid = 1;
+		break;
+	case CHECKSUM_UNNECESSARY:
+		NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
 		break;
 	}
-	rcu_read_unlock();
 
-	if (&ptype->list == head)
-		goto normal;
+	pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive,
+				ipv6_gro_receive, inet_gro_receive,
+				&gro_list->list, skb);
+
+	rcu_read_unlock();
 
 	if (PTR_ERR(pp) == -EINPROGRESS) {
 		ret = GRO_CONSUMED;