Re: OOPS, ip -f inet6 route get fec0::1, linux-2.6.26, ip6_route_output, rt6_fill_node+0x175
From: Eugene Teo <hidden>
Date: 2008-08-11 11:04:35
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Subsystem:
networking [general], networking [ipsec], networking [ipv4/ipv6], sctp protocol, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Steffen Klassert, Herbert Xu, David Ahern, Ido Schimmel, Marcelo Ricardo Leitner, Xin Long, Linus Torvalds
Hi, <quote sender="Brian Haley">
Alexey Dobriyan wrote:quoted
On Thu, Aug 07, 2008 at 07:00:56PM +0200, John Gumb wrote:
[...]
The commit that changed this can't be reverted easily, but the patch below works for me. Fix NULL de-reference in rt6_fill_node() when there's no IPv6 input device present in the dst entry. Signed-off-by: Brian Haley <redacted>
I think it's better to use a helper routine like ipv6_get_saddr to make sure that both dst and rt6i_idev arguments are checked for NULL. I have compiled, and tested the patch. Thanks, Eugene --- Fix NULL pointer dereference in rt6_fill_node(). # ip -f inet6 route get fec0::1 BUG: unable to handle kernel NULL pointer dereference at 00000000 IP: [<c0369b85>] rt6_fill_node+0x175/0x3b0 EIP is at rt6_fill_node+0x175/0x3b0 Cc: Stable <stable@kernel.org> Signed-off-by: Eugene Teo <redacted> --- include/net/addrconf.h | 4 ++++ include/net/ip6_fib.h | 2 +- net/ipv6/addrconf.c | 8 ++++++++ net/ipv6/fib6_rules.c | 3 +-- net/ipv6/ip6_output.c | 3 +-- net/ipv6/route.c | 3 +-- net/ipv6/xfrm6_policy.c | 3 +-- net/sctp/ipv6.c | 3 +-- 8 files changed, 18 insertions(+), 11 deletions(-)
diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index 06b2814..c43ad8e 100644
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h@@ -80,6 +80,10 @@ extern struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, struct net_device *dev, int strict); +extern int ipv6_get_saddr(struct dst_entry *dst, + const struct in6_addr *daddr, + unsigned int srcprefs, + struct in6_addr *saddr); extern int ipv6_dev_get_saddr(struct net_device *dev, const struct in6_addr *daddr, unsigned int srcprefs,
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 7c5c0f7..73f7f6b 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h@@ -118,7 +118,7 @@ struct rt6_info static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) { - return ((struct rt6_info *)dst)->rt6i_idev; + return dst ? ((struct rt6_info *)dst)->rt6i_idev : NULL; } struct fib6_walker_t
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index a7842c5..55647bd 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c@@ -1239,6 +1239,14 @@ try_nextdev: return 0; } +int ipv6_get_saddr(struct dst_entry *dst, const struct in6_addr *daddr, + unsigned int srcprefs, struct in6_addr *saddr) +{ + struct inet6_dev *idev = ip6_dst_idev(dst); + return ipv6_dev_get_saddr(idev ? idev->dev : NULL, daddr, srcprefs, saddr); + +} +EXPORT_SYMBOL(ipv6_get_saddr); EXPORT_SYMBOL(ipv6_dev_get_saddr); int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr,
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 8d05527..27c859c 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c@@ -93,8 +93,7 @@ static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp, if (flags & RT6_LOOKUP_F_SRCPREF_COA) srcprefs |= IPV6_PREFER_SRC_COA; - if (ipv6_dev_get_saddr(ip6_dst_idev(&rt->u.dst)->dev, - &flp->fl6_dst, srcprefs, + if (ipv6_get_saddr(&rt->u.dst, &flp->fl6_dst, srcprefs, &saddr)) goto again; if (!ipv6_prefix_equal(&saddr, &r->src.addr,
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index a4402de..fc5f4f4 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c@@ -934,8 +934,7 @@ static int ip6_dst_lookup_tail(struct sock *sk, goto out_err_release; if (ipv6_addr_any(&fl->fl6_src)) { - err = ipv6_dev_get_saddr(ip6_dst_idev(*dst)->dev, - &fl->fl6_dst, + err = ipv6_get_saddr(*dst, &fl->fl6_dst, sk ? inet6_sk(sk)->srcprefs : 0, &fl->fl6_src); if (err)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 5a3e87e..950d709 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c@@ -2188,8 +2188,7 @@ static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt, NLA_PUT_U32(skb, RTA_IIF, iif); } else if (dst) { struct in6_addr saddr_buf; - if (ipv6_dev_get_saddr(ip6_dst_idev(&rt->u.dst)->dev, - dst, 0, &saddr_buf) == 0) + if (ipv6_get_saddr(&rt->u.dst, dst, 0, &saddr_buf) == 0) NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf); }
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 8f1e054..ad582bd 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c@@ -57,8 +57,7 @@ static int xfrm6_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr) if (IS_ERR(dst)) return -EHOSTUNREACH; - ipv6_dev_get_saddr(ip6_dst_idev(dst)->dev, - (struct in6_addr *)&daddr->a6, 0, + ipv6_get_saddr(dst, (struct in6_addr *)&daddr->a6, 0, (struct in6_addr *)&saddr->a6); dst_release(dst); return 0;
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 483a01d..0fa9411 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c@@ -319,8 +319,7 @@ static void sctp_v6_get_saddr(struct sctp_sock *sk, __func__, asoc, dst, NIP6(daddr->v6.sin6_addr)); if (!asoc) { - ipv6_dev_get_saddr(dst ? ip6_dst_idev(dst)->dev : NULL, - &daddr->v6.sin6_addr, + ipv6_get_saddr(dst, &daddr->v6.sin6_addr, inet6_sk(&sk->inet.sk)->srcprefs, &saddr->v6.sin6_addr); SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: " NIP6_FMT "\n",