diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-11-02 07:53:17 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-11-21 10:11:34 +0100 |
| commit | 842a858fa048294c86837be560c277abf1611246 (patch) | |
| tree | c22dc0a901336d8ff31ac4a53b173b6e6a04e101 /net | |
| parent | fc3b825f2c81a627459fd261faca10afa94cf087 (diff) | |
| download | lwn-842a858fa048294c86837be560c277abf1611246.tar.gz lwn-842a858fa048294c86837be560c277abf1611246.zip | |
tcp: fix potential memory corruption
[ Upstream commit ac9e70b17ecd7c6e933ff2eaf7ab37429e71bf4d ]
Imagine initial value of max_skb_frags is 17, and last
skb in write queue has 15 frags.
Then max_skb_frags is lowered to 14 or smaller value.
tcp_sendmsg() will then be allowed to add additional page frags
and eventually go past MAX_SKB_FRAGS, overflowing struct
skb_shared_info.
Fixes: 5f74f82ea34c ("net:Add sysctl_max_skb_frags")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hans Westgaard Ry <hans.westgaard.ry@oracle.com>
Cc: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index ffbb218de520..e5d11df75670 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1219,7 +1219,7 @@ new_segment: if (!skb_can_coalesce(skb, i, pfrag->page, pfrag->offset)) { - if (i == sysctl_max_skb_frags || !sg) { + if (i >= sysctl_max_skb_frags || !sg) { tcp_mark_push(tp, skb); goto new_segment; } |