lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Sat, 25 Jul 2020 16:02:18 +0800
From:   Xiyu Yang <>
To:     "David S. Miller" <>,
        Alexey Kuznetsov <>,
        Hideaki YOSHIFUJI <>,
        Jakub Kicinski <>,,
Cc:     Xiyu Yang <>, Xin Tan <>
Subject: [PATCH] ipv6: Fix nexthop refcnt leak when creating ipv6 route info

ip6_route_info_create() invokes nexthop_get(), which increases the
refcount of the "nh".

When ip6_route_info_create() returns, local variable "nh" becomes
invalid, so the refcount should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
ip6_route_info_create(). When nexthops can not be used with source
routing, the function forgets to decrease the refcnt increased by
nexthop_get(), causing a refcnt leak.

Fix this issue by pulling up the error source routing handling when
nexthops can not be used with source routing.

Signed-off-by: Xiyu Yang <>
Signed-off-by: Xin Tan <>
 net/ipv6/route.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 82cbb46a2a4f..427ecd7032bd 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3682,14 +3682,14 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
 	rt->fib6_src.plen = cfg->fc_src_len;
 	if (nh) {
-		if (!nexthop_get(nh)) {
-			NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
-			goto out;
-		}
 		if (rt->fib6_src.plen) {
 			NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
 			goto out;
+		if (!nexthop_get(nh)) {
+			NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
+			goto out;
+		}
 		rt->nh = nh;
 		fib6_nh = nexthop_fib6_nh(rt->nh);
 	} else {

Powered by blists - more mailing lists