Commit 6e992dc4 authored by Liu Jian's avatar Liu Jian
Browse files

net: ipv4: fix one memleak in __inet_del_ifa() 

mainline inclusion
from mainline-v6.6-rc2
commit ac28b1ec
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I869PY
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=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 4.117.174.103/0 scope 0x40 dev bond0
ip addr add 192.168.100.111/255.255.255.254 scope 0 dev bond0
ip addr add 0.0.0.4/0 scope 0x40 secondary dev bond0
ip addr del 4.117.174.103/0 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(0.0.0.4/0 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: 0ff60a45 ("[IPV4]: Fix secondary IP addresses after promotion")
Signed-off-by: default avatarLiu Jian <liujian56@huawei.com>
Signed-off-by: default avatarJulian Anastasov <ja@ssi.bg>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarLiu Jian <liujian56@huawei.com>

Conflicts:
	net/ipv4/devinet.c
parent e1d1636c

net/ipv4/devinet.c

+5 −4
Original line number Diff line number Diff line
@@ -341,12 +341,13 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap, 
{

	struct in_ifaddr *promote = NULL;

	struct in_ifaddr *ifa, *ifa1 = *ifap;

	struct in_ifaddr *last_prim = in_dev->ifa_list;

	struct in_ifaddr **last_prim;

	struct in_ifaddr *prev_prom = NULL;

	int do_promote = IN_DEV_PROMOTE_SECONDARIES(in_dev);



	ASSERT_RTNL();



	last_prim = ifap;

	if (in_dev->dead)

		goto no_promotions;
@@ -360,7 +361,7 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap, 
		while ((ifa = *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 ||
@@ -420,8 +421,8 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap, 


		if (prev_prom) {

			prev_prom->ifa_next = promote->ifa_next;

			promote->ifa_next = last_prim->ifa_next;

			last_prim->ifa_next = promote;

			promote->ifa_next = *last_prim;

			*last_prim = promote;

		}



		promote->ifa_flags &= ~IFA_F_SECONDARY;