Commit b90ddd56 authored Dec 20, 2017 by Willem de Bruijn Committed by David S. Miller Dec 21, 2017

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: 3ece7826 ("sock: skb_copy_ubufs support for compound pages")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 268b7906

net/core/skbuff.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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;
		}

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