skbuff: skb_copy_ubufs must release uarg even without user frags

skb_copy_ubufs creates a private copy of frags[] to release its hold on user frags, then calls uarg->callback to notify the owner. Call uarg->callback even when no frags exist. This edge case can happen when zerocopy_sg_from_iter finds enough room in skb_headlen to copy all the data. Fixes: 3ece782 ("sock: skb_copy_ubufs support for compound pages") Signed-off-by: Willem de Bruijn <[email protected]> Signed-off-by: David S. Miller <[email protected]>
chasrmartin · Dec 21, 2017 · b90ddd5 · b90ddd5
1 parent 268b790
commit b90ddd5
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
@@ -1178,7 +1178,7 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
 	u32 d_off;
 
 	if (!num_frags)
-		return 0;
+		goto release;
 
 	if (skb_shared(skb) || skb_unclone(skb, gfp_mask))
 		return -EINVAL;
@@ -1238,6 +1238,7 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
 	__skb_fill_page_desc(skb, new_frags - 1, head, 0, d_off);
 	skb_shinfo(skb)->nr_frags = new_frags;
 
+release:
 	skb_zcopy_clear(skb, false);
 	return 0;
 }