From a7f9a6f4cc5fb4d5c5a03f3f898b7cb86db05cbf Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Sat, 4 Apr 2020 11:22:57 -0400 Subject: ipv6: rpl: fix loop iteration This patch fix the loop iteration by not walking over the last iteration. The cmpri compressing value exempt the last segment. As the code shows the last iteration will be overwritten by cmpre value handling which is for the last segment. I think this doesn't end in any bufferoverflows because we work on worst case temporary buffer sizes but it ends in not best compression settings in some cases. Fixes: 8610c7c6e3bd ("net: ipv6: add support for rpl sr exthdr") Signed-off-by: Alexander Aring Signed-off-by: David S. Miller --- net/ipv6/rpl.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/rpl.c b/net/ipv6/rpl.c index dc4f20e23bf7..d38b476fc7f2 100644 --- a/net/ipv6/rpl.c +++ b/net/ipv6/rpl.c @@ -48,7 +48,7 @@ void ipv6_rpl_srh_decompress(struct ipv6_rpl_sr_hdr *outhdr, outhdr->cmpri = 0; outhdr->cmpre = 0; - for (i = 0; i <= n; i++) + for (i = 0; i < n; i++) ipv6_rpl_addr_decompress(&outhdr->rpl_segaddr[i], daddr, ipv6_rpl_segdata_pos(inhdr, i), inhdr->cmpri); @@ -66,7 +66,7 @@ static unsigned char ipv6_rpl_srh_calc_cmpri(const struct ipv6_rpl_sr_hdr *inhdr int i; for (plen = 0; plen < sizeof(*daddr); plen++) { - for (i = 0; i <= n; i++) { + for (i = 0; i < n; i++) { if (daddr->s6_addr[plen] != inhdr->rpl_segaddr[i].s6_addr[plen]) return plen; @@ -114,7 +114,7 @@ void ipv6_rpl_srh_compress(struct ipv6_rpl_sr_hdr *outhdr, outhdr->cmpri = cmpri; outhdr->cmpre = cmpre; - for (i = 0; i <= n; i++) + for (i = 0; i < n; i++) ipv6_rpl_addr_compress(ipv6_rpl_segdata_pos(outhdr, i), &inhdr->rpl_segaddr[i], cmpri); -- cgit v1.2.3