diff options
| author | Prasad J Pandit <pjp@fedoraproject.org> | 2016-03-02 17:29:58 +0530 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2016-03-22 17:40:27 -0500 |
| commit | d0ee85b4e4c6cc2c8fac311d6df2ed412ed0df5f (patch) | |
| tree | 8232261dd44d61bed69a4d93f2e99f0be811da2f /net | |
| parent | 4f046a6ba1d558eb043dc13a80d40cf7cb62ef95 (diff) | |
net: check packet payload length
While computing IP checksum, 'net_checksum_calculate' reads
payload length from the packet. It could exceed the given 'data'
buffer size. Add a check to avoid it.
Reported-by: Liu Ling <liuling-it@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
(cherry picked from commit 362786f14a753d8a5256ef97d7c10ed576d6572b)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/checksum.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/net/checksum.c b/net/checksum.c index 14c08550e0..0942437c05 100644 --- a/net/checksum.c +++ b/net/checksum.c @@ -59,6 +59,11 @@ void net_checksum_calculate(uint8_t *data, int length) int hlen, plen, proto, csum_offset; uint16_t csum; + /* Ensure data has complete L2 & L3 headers. */ + if (length < 14 + 20) { + return; + } + if ((data[14] & 0xf0) != 0x40) return; /* not IPv4 */ hlen = (data[14] & 0x0f) * 4; @@ -76,8 +81,9 @@ void net_checksum_calculate(uint8_t *data, int length) return; } - if (plen < csum_offset+2) - return; + if (plen < csum_offset + 2 || 14 + hlen + plen > length) { + return; + } data[14+hlen+csum_offset] = 0; data[14+hlen+csum_offset+1] = 0; |