[PATCH 5.4 297/367] net: ipv4: fix one memleak in __inet_del_ifa()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


5.4-stable review patch.  If anyone has any objections, please let me know.


From: Liu Jian <liujian56@xxxxxxxxxx>

[ Upstream commit ac28b1ec6135649b5d78b028e47264cb3ebca5ea ]

I got the below warning when do fuzzing test:
unregister_netdevice: waiting for bond0 to become free. Usage count = 2

It can be repoduced via:

ip link add bond0 type bond
sysctl -w net.ipv4.conf.bond0.promote_secondaries=1
ip addr add scope 0x40 dev bond0
ip addr add scope 0 dev bond0
ip addr add scope 0x40 secondary dev bond0
ip addr del scope 0x40 dev bond0
ip link delete bond0 type bond

In this reproduction test case, an incorrect 'last_prim' is found in
__inet_del_ifa(), as a result, the secondary address( scope 0x40)
is lost. The memory of the secondary address is leaked and the reference of
in_device and net_device is leaked.

Fix this problem:
Look for 'last_prim' starting at location of the deleted IP and inserting
the promoted IP into the location of 'last_prim'.

Fixes: 0ff60a45678e ("[IPV4]: Fix secondary IP addresses after promotion")
Signed-off-by: Liu Jian <liujian56@xxxxxxxxxx>
Signed-off-by: Julian Anastasov <ja@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
 net/ipv4/devinet.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 4a8ad46397c0e..4c013f8800f0c 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -351,14 +351,14 @@ static void __inet_del_ifa(struct in_device *in_dev,
 	struct in_ifaddr *promote = NULL;
 	struct in_ifaddr *ifa, *ifa1;
-	struct in_ifaddr *last_prim;
+	struct in_ifaddr __rcu **last_prim;
 	struct in_ifaddr *prev_prom = NULL;
 	int do_promote = IN_DEV_PROMOTE_SECONDARIES(in_dev);
 	ifa1 = rtnl_dereference(*ifap);
-	last_prim = rtnl_dereference(in_dev->ifa_list);
+	last_prim = ifap;
 	if (in_dev->dead)
 		goto no_promotions;
@@ -372,7 +372,7 @@ static void __inet_del_ifa(struct in_device *in_dev,
 		while ((ifa = rtnl_dereference(*ifap1)) != NULL) {
 			if (!(ifa->ifa_flags & IFA_F_SECONDARY) &&
 			    ifa1->ifa_scope <= ifa->ifa_scope)
-				last_prim = ifa;
+				last_prim = &ifa->ifa_next;
 			if (!(ifa->ifa_flags & IFA_F_SECONDARY) ||
 			    ifa1->ifa_mask != ifa->ifa_mask ||
@@ -436,9 +436,9 @@ static void __inet_del_ifa(struct in_device *in_dev,
 			rcu_assign_pointer(prev_prom->ifa_next, next_sec);
-			last_sec = rtnl_dereference(last_prim->ifa_next);
+			last_sec = rtnl_dereference(*last_prim);
 			rcu_assign_pointer(promote->ifa_next, last_sec);
-			rcu_assign_pointer(last_prim->ifa_next, promote);
+			rcu_assign_pointer(*last_prim, promote);
 		promote->ifa_flags &= ~IFA_F_SECONDARY;

[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux