This is a note to let you know that I've just added the patch titled net/802/mrp: fix memleak in mrp_request_join() to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-802-mrp-fix-memleak-in-mrp_request_join.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 17190f322d781a5672be73939c3d14a0efa9bc83 Author: Yang Yingliang <yangyingliang@xxxxxxxxxx> Date: Tue Jun 29 15:22:37 2021 +0800 net/802/mrp: fix memleak in mrp_request_join() [ Upstream commit 996af62167d0e0ec69b938a3561e96f84ffff1aa ] I got kmemleak report when doing fuzz test: BUG: memory leak unreferenced object 0xffff88810c239500 (size 64): comm "syz-executor940", pid 882, jiffies 4294712870 (age 14.631s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 01 00 00 00 01 02 00 04 ................ backtrace: [<00000000a323afa4>] slab_alloc_node mm/slub.c:2972 [inline] [<00000000a323afa4>] slab_alloc mm/slub.c:2980 [inline] [<00000000a323afa4>] __kmalloc+0x167/0x340 mm/slub.c:4130 [<000000005034ca11>] kmalloc include/linux/slab.h:595 [inline] [<000000005034ca11>] mrp_attr_create net/802/mrp.c:276 [inline] [<000000005034ca11>] mrp_request_join+0x265/0x550 net/802/mrp.c:530 [<00000000fcfd81f3>] vlan_mvrp_request_join+0x145/0x170 net/8021q/vlan_mvrp.c:40 [<000000009258546e>] vlan_dev_open+0x477/0x890 net/8021q/vlan_dev.c:292 [<0000000059acd82b>] __dev_open+0x281/0x410 net/core/dev.c:1609 [<000000004e6dc695>] __dev_change_flags+0x424/0x560 net/core/dev.c:8767 [<00000000471a09af>] rtnl_configure_link+0xd9/0x210 net/core/rtnetlink.c:3122 [<0000000037a4672b>] __rtnl_newlink+0xe08/0x13e0 net/core/rtnetlink.c:3448 [<000000008d5d0fda>] rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3488 [<000000004882fe39>] rtnetlink_rcv_msg+0x369/0xa10 net/core/rtnetlink.c:5552 [<00000000907e6c54>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504 [<00000000e7d7a8c4>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] [<00000000e7d7a8c4>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340 [<00000000e0645d50>] netlink_sendmsg+0x78e/0xc90 net/netlink/af_netlink.c:1929 [<00000000c24559b7>] sock_sendmsg_nosec net/socket.c:654 [inline] [<00000000c24559b7>] sock_sendmsg+0x139/0x170 net/socket.c:674 [<00000000fc210bc2>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350 [<00000000be4577b5>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404 Calling mrp_request_leave() after mrp_request_join(), the attr->state is set to MRP_APPLICANT_VO, mrp_attr_destroy() won't be called in last TX event in mrp_uninit_applicant(), the attr of applicant will be leaked. To fix this leak, iterate and free each attr of applicant before rerturning from mrp_uninit_applicant(). Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/802/mrp.c b/net/802/mrp.c index be4dd3165347..7a893a03e795 100644 --- a/net/802/mrp.c +++ b/net/802/mrp.c @@ -295,6 +295,19 @@ static void mrp_attr_destroy(struct mrp_applicant *app, struct mrp_attr *attr) kfree(attr); } +static void mrp_attr_destroy_all(struct mrp_applicant *app) +{ + struct rb_node *node, *next; + struct mrp_attr *attr; + + for (node = rb_first(&app->mad); + next = node ? rb_next(node) : NULL, node != NULL; + node = next) { + attr = rb_entry(node, struct mrp_attr, node); + mrp_attr_destroy(app, attr); + } +} + static int mrp_pdu_init(struct mrp_applicant *app) { struct sk_buff *skb; @@ -899,6 +912,7 @@ void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl) spin_lock_bh(&app->lock); mrp_mad_event(app, MRP_EVENT_TX); + mrp_attr_destroy_all(app); mrp_pdu_queue(app); spin_unlock_bh(&app->lock);