From: Xin Long lucien.xin@gmail.com
[ Upstream commit a482c5e00a9b5a194085bcd372ac36141028becb ]
In rt_mt6(), when it's a nonlinear skb, the 1st skb_header_pointer() only copies sizeof(struct ipv6_rt_hdr) to _route that rh points to. The access by ((const struct rt0_hdr *)rh)->reserved will overflow the buffer. So this access should be moved below the 2nd call to skb_header_pointer().
Besides, after the 2nd skb_header_pointer(), its return value should also be checked, othersize, *rp may cause null-pointer-ref.
v1->v2: - clean up some old debugging log.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Xin Long lucien.xin@gmail.com Acked-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv6/netfilter/ip6t_rt.c | 48 +++++------------------------------- 1 file changed, 6 insertions(+), 42 deletions(-)
diff --git a/net/ipv6/netfilter/ip6t_rt.c b/net/ipv6/netfilter/ip6t_rt.c index 733c83d38b30..4ad8b2032f1f 100644 --- a/net/ipv6/netfilter/ip6t_rt.c +++ b/net/ipv6/netfilter/ip6t_rt.c @@ -25,12 +25,7 @@ MODULE_AUTHOR("Andras Kis-Szabo kisza@sch.bme.hu"); static inline bool segsleft_match(u_int32_t min, u_int32_t max, u_int32_t id, bool invert) { - bool r; - pr_debug("segsleft_match:%c 0x%x <= 0x%x <= 0x%x\n", - invert ? '!' : ' ', min, id, max); - r = (id >= min && id <= max) ^ invert; - pr_debug(" result %s\n", r ? "PASS" : "FAILED"); - return r; + return (id >= min && id <= max) ^ invert; }
static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par) @@ -65,30 +60,6 @@ static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par) return false; }
- pr_debug("IPv6 RT LEN %u %u ", hdrlen, rh->hdrlen); - pr_debug("TYPE %04X ", rh->type); - pr_debug("SGS_LEFT %u %02X\n", rh->segments_left, rh->segments_left); - - pr_debug("IPv6 RT segsleft %02X ", - segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1], - rh->segments_left, - !!(rtinfo->invflags & IP6T_RT_INV_SGS))); - pr_debug("type %02X %02X %02X ", - rtinfo->rt_type, rh->type, - (!(rtinfo->flags & IP6T_RT_TYP) || - ((rtinfo->rt_type == rh->type) ^ - !!(rtinfo->invflags & IP6T_RT_INV_TYP)))); - pr_debug("len %02X %04X %02X ", - rtinfo->hdrlen, hdrlen, - !(rtinfo->flags & IP6T_RT_LEN) || - ((rtinfo->hdrlen == hdrlen) ^ - !!(rtinfo->invflags & IP6T_RT_INV_LEN))); - pr_debug("res %02X %02X %02X ", - rtinfo->flags & IP6T_RT_RES, - ((const struct rt0_hdr *)rh)->reserved, - !((rtinfo->flags & IP6T_RT_RES) && - (((const struct rt0_hdr *)rh)->reserved))); - ret = (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1], rh->segments_left, !!(rtinfo->invflags & IP6T_RT_INV_SGS))) && @@ -107,22 +78,22 @@ static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par) reserved), sizeof(_reserved), &_reserved); + if (!rp) { + par->hotdrop = true; + return false; + }
ret = (*rp == 0); }
- pr_debug("#%d ", rtinfo->addrnr); if (!(rtinfo->flags & IP6T_RT_FST)) { return ret; } else if (rtinfo->flags & IP6T_RT_FST_NSTRICT) { - pr_debug("Not strict "); if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) { - pr_debug("There isn't enough space\n"); return false; } else { unsigned int i = 0;
- pr_debug("#%d ", rtinfo->addrnr); for (temp = 0; temp < (unsigned int)((hdrlen - 8) / 16); temp++) { @@ -138,26 +109,20 @@ static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par) return false; }
- if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) { - pr_debug("i=%d temp=%d;\n", i, temp); + if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) i++; - } if (i == rtinfo->addrnr) break; } - pr_debug("i=%d #%d\n", i, rtinfo->addrnr); if (i == rtinfo->addrnr) return ret; else return false; } } else { - pr_debug("Strict "); if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) { - pr_debug("There isn't enough space\n"); return false; } else { - pr_debug("#%d ", rtinfo->addrnr); for (temp = 0; temp < rtinfo->addrnr; temp++) { ap = skb_header_pointer(skb, ptr @@ -173,7 +138,6 @@ static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par) if (!ipv6_addr_equal(ap, &rtinfo->addrs[temp])) break; } - pr_debug("temp=%d #%d\n", temp, rtinfo->addrnr); if (temp == rtinfo->addrnr && temp == (unsigned int)((hdrlen - 8) / 16)) return ret;