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authorYOSHIFUJI Hideaki/吉藤英明 <hideaki.yoshifuji@miraclelinux.com>2015-07-13 16:28:10 +0200
committerDavid S. Miller <davem@davemloft.net>2015-07-16 06:06:13 +0200
commitc0b8da1e7613a11ce7e44560aae507b62da1f846 (patch)
treeb56047ea80fc041c36996a98f62e97e10e7f22a5 /net/ipv6
parentMerge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsh... (diff)
downloadlinux-c0b8da1e7613a11ce7e44560aae507b62da1f846.tar.xz
linux-c0b8da1e7613a11ce7e44560aae507b62da1f846.zip
ipv6: Fix finding best source address in ipv6_dev_get_saddr().
Commit 9131f3de2 ("ipv6: Do not iterate over all interfaces when finding source address on specific interface.") did not properly update best source address available. Plus, it introduced possible NULL pointer dereference. Bug was reported by Erik Kline <ek@google.com>. Based on patch proposed by Hajime Tazaki <thehajime@gmail.com>. Fixes: 9131f3de24db4dc12199aede7d931e6703e97f3b ("ipv6: Do not iterate over all interfaces when finding source address on specific interface.") Signed-off-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com> Acked-by: Hajime Tazaki <thehajime@gmail.com> Acked-by: Erik Kline <ek@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/addrconf.c30
1 files changed, 18 insertions, 12 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 4ab74d56f65a..4c9a0246ef48 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1358,14 +1358,15 @@ out:
return ret;
}
-static void __ipv6_dev_get_saddr(struct net *net,
- struct ipv6_saddr_dst *dst,
- unsigned int prefs,
- const struct in6_addr *saddr,
- struct inet6_dev *idev,
- struct ipv6_saddr_score *scores)
+static int __ipv6_dev_get_saddr(struct net *net,
+ struct ipv6_saddr_dst *dst,
+ unsigned int prefs,
+ const struct in6_addr *saddr,
+ struct inet6_dev *idev,
+ struct ipv6_saddr_score *scores,
+ int hiscore_idx)
{
- struct ipv6_saddr_score *score = &scores[0], *hiscore = &scores[1];
+ struct ipv6_saddr_score *score = &scores[1 - hiscore_idx], *hiscore = &scores[hiscore_idx];
read_lock_bh(&idev->lock);
list_for_each_entry(score->ifa, &idev->addr_list, if_list) {
@@ -1424,6 +1425,7 @@ static void __ipv6_dev_get_saddr(struct net *net,
in6_ifa_hold(score->ifa);
swap(hiscore, score);
+ hiscore_idx = 1 - hiscore_idx;
/* restore our iterator */
score->ifa = hiscore->ifa;
@@ -1434,18 +1436,20 @@ static void __ipv6_dev_get_saddr(struct net *net,
}
out:
read_unlock_bh(&idev->lock);
+ return hiscore_idx;
}
int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
const struct in6_addr *daddr, unsigned int prefs,
struct in6_addr *saddr)
{
- struct ipv6_saddr_score scores[2], *hiscore = &scores[1];
+ struct ipv6_saddr_score scores[2], *hiscore;
struct ipv6_saddr_dst dst;
struct inet6_dev *idev;
struct net_device *dev;
int dst_type;
bool use_oif_addr = false;
+ int hiscore_idx = 0;
dst_type = __ipv6_addr_type(daddr);
dst.addr = daddr;
@@ -1454,8 +1458,8 @@ int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
dst.label = ipv6_addr_label(net, daddr, dst_type, dst.ifindex);
dst.prefs = prefs;
- hiscore->rule = -1;
- hiscore->ifa = NULL;
+ scores[hiscore_idx].rule = -1;
+ scores[hiscore_idx].ifa = NULL;
rcu_read_lock();
@@ -1480,17 +1484,19 @@ int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
}
if (use_oif_addr) {
- __ipv6_dev_get_saddr(net, &dst, prefs, saddr, idev, scores);
+ if (idev)
+ hiscore_idx = __ipv6_dev_get_saddr(net, &dst, prefs, saddr, idev, scores, hiscore_idx);
} else {
for_each_netdev_rcu(net, dev) {
idev = __in6_dev_get(dev);
if (!idev)
continue;
- __ipv6_dev_get_saddr(net, &dst, prefs, saddr, idev, scores);
+ hiscore_idx = __ipv6_dev_get_saddr(net, &dst, prefs, saddr, idev, scores, hiscore_idx);
}
}
rcu_read_unlock();
+ hiscore = &scores[hiscore_idx];
if (!hiscore->ifa)
return -EADDRNOTAVAIL;