Patch "skbuff: skb_copy_ubufs must release uarg even without user frags" has been added to the 4.14-stable tree

Patch "skbuff: skb_copy_ubufs must release uarg even without user frags" has been added to the 4.14-stable tree

[gregkh]

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

    skbuff: skb_copy_ubufs must release uarg even without user frags

to the 4.14-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:
     skbuff-skb_copy_ubufs-must-release-uarg-even-without-user-frags.patch
and it can be found in the queue-4.14 subdirectory.

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


>From foo@baz Sun Dec 31 11:12:48 CET 2017
From: Willem de Bruijn <willemb@google.com>
Date: Wed, 20 Dec 2017 17:37:50 -0500
Subject: skbuff: skb_copy_ubufs must release uarg even without user frags

From: Willem de Bruijn <willemb@google.com>


[ Upstream commit b90ddd568792bcb0054eaf0f61785c8f80c3bd1c ]

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: 3ece782693c4 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/core/skbuff.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1182,7 +1182,7 @@ int skb_copy_ubufs(struct sk_buff *skb,
 	u32 d_off;
 
 	if (!num_frags)
-		return 0;
+		goto release;
 
 	if (skb_shared(skb) || skb_unclone(skb, gfp_mask))
 		return -EINVAL;
@@ -1242,6 +1242,7 @@ int skb_copy_ubufs(struct sk_buff *skb,
 	__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;
 }


Patches currently in stable-queue which might be from willemb@google.com are

queue-4.14/skbuff-skb_copy_ubufs-must-release-uarg-even-without-user-frags.patch
queue-4.14/sock-free-skb-in-skb_complete_tx_timestamp-on-error.patch
queue-4.14/skbuff-orphan-frags-before-zerocopy-clone.patch
queue-4.14/skbuff-in-skb_copy_ubufs-unclone-before-releasing-zerocopy.patch