diff options
| author | Sabrina Dubroca <sd@queasysnail.net> | 2015-10-15 12:25:00 -0500 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2016-11-17 12:12:22 +0100 |
| commit | d144ca5dd27898b4edbd407f7d4944f71a544252 (patch) | |
| tree | 527e6c0dde8047749e121057ea792ba755a063b6 /net/core | |
| parent | 6988083d00a11de2741d172fea664257f0e61d35 (diff) | |
net: add length argument to skb_copy_and_csum_datagram_iovec
Without this length argument, we can read past the end of the iovec in
memcpy_toiovec because we have no way of knowing the total length of the
iovec's buffers.
This is needed for stable kernels where 89c22d8c3b27 ("net: Fix skb
csum races when peeking") has been backported but that don't have the
ioviter conversion, which is almost all the stable trees <= 3.18.
This also fixes a kernel crash for NFS servers when the client uses
-onfsvers=3,proto=udp to mount the export.
Change-Id: I1865e3d7a1faee42a5008a9ad58c4d3323ea4bab
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
(cherry picked from commit 1644c6f70701fea6b3f8bbe3130d5633a5ec14f0)
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/datagram.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index 052b71c5b..ed5ffb6ae 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -719,6 +719,7 @@ EXPORT_SYMBOL(__skb_checksum_complete); * @skb: skbuff * @hlen: hardware length * @iov: io vector + * @len: amount of data to copy from skb to iov * * Caller _must_ check that skb will fit to this iovec. * @@ -728,11 +729,14 @@ EXPORT_SYMBOL(__skb_checksum_complete); * can be modified! */ int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, - int hlen, struct iovec *iov) + int hlen, struct iovec *iov, int len) { __wsum csum; int chunk = skb->len - hlen; + if (chunk > len) + chunk = len; + if (!chunk) return 0; |