4.4-stable review patch. If anyone has any objections, please let me know.
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From: yujuan.qi yujuan.qi@mediatek.com
commit 40413955ee265a5e42f710940ec78f5450d49149 upstream.
in for(),if((optlen > 0) && (optptr[1] == 0)), enter infinite loop.
Test: receive a packet which the ip length > 20 and the first byte of ip option is 0, produce this issue
Signed-off-by: yujuan.qi yujuan.qi@mediatek.com Acked-by: Paul Moore paul@paul-moore.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/ipv4/cipso_ipv4.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
--- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -1593,9 +1593,17 @@ unsigned char *cipso_v4_optptr(const str int taglen;
for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 0; ) { - if (optptr[0] == IPOPT_CIPSO) + switch (optptr[0]) { + case IPOPT_CIPSO: return optptr; - taglen = optptr[1]; + case IPOPT_END: + return NULL; + case IPOPT_NOOP: + taglen = 1; + break; + default: + taglen = optptr[1]; + } optlen -= taglen; optptr += taglen; }