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author | Prasad J Pandit <pjp@fedoraproject.org> | 2016-03-02 17:29:58 +0530 |
---|---|---|
committer | Timothy Pearson <tpearson@raptorengineering.com> | 2019-11-29 19:49:13 -0600 |
commit | be0edaacdca101bfce57861bb8bebf24683900b1 (patch) | |
tree | 993f9f33c0afe949bdb354d3e653235334d9a305 /net | |
parent | 65929590ea021ab5f74533bd88d7e351412f69ce (diff) | |
download | hqemu-be0edaacdca101bfce57861bb8bebf24683900b1.zip hqemu-be0edaacdca101bfce57861bb8bebf24683900b1.tar.gz |
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>
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 b5016ab..d0fa424 100644 --- a/net/checksum.c +++ b/net/checksum.c @@ -60,6 +60,11 @@ 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; @@ -77,8 +82,9 @@ 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; |