This is a note to let you know that I've just added the patch titled net/802/garp: fix memleak in garp_request_join() to the 4.19-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-garp-fix-memleak-in-garp_request_join.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 273bb2f6423f1662fd5a5f8bd1ad71a6b499e2b2 Author: Yang Yingliang <yangyingliang@xxxxxxxxxx> Date: Tue Jun 29 19:53:28 2021 +0800 net/802/garp: fix memleak in garp_request_join() [ Upstream commit 42ca63f980842918560b25f0244307fd83b4777c ] I got kmemleak report when doing fuzz test: BUG: memory leak unreferenced object 0xffff88810c909b80 (size 64): comm "syz", pid 957, jiffies 4295220394 (age 399.090s) 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 08 00 00 00 01 02 00 04 ................ backtrace: [<00000000ca1f2e2e>] garp_request_join+0x285/0x3d0 [<00000000bf153351>] vlan_gvrp_request_join+0x15b/0x190 [<0000000024005e72>] vlan_dev_open+0x706/0x980 [<00000000dc20c4d4>] __dev_open+0x2bb/0x460 [<0000000066573004>] __dev_change_flags+0x501/0x650 [<0000000035b42f83>] rtnl_configure_link+0xee/0x280 [<00000000a5e69de0>] __rtnl_newlink+0xed5/0x1550 [<00000000a5258f4a>] rtnl_newlink+0x66/0x90 [<00000000506568ee>] rtnetlink_rcv_msg+0x439/0xbd0 [<00000000b7eaeae1>] netlink_rcv_skb+0x14d/0x420 [<00000000c373ce66>] netlink_unicast+0x550/0x750 [<00000000ec74ce74>] netlink_sendmsg+0x88b/0xda0 [<00000000381ff246>] sock_sendmsg+0xc9/0x120 [<000000008f6a2db3>] ____sys_sendmsg+0x6e8/0x820 [<000000008d9c1735>] ___sys_sendmsg+0x145/0x1c0 [<00000000aa39dd8b>] __sys_sendmsg+0xfe/0x1d0 Calling garp_request_leave() after garp_request_join(), the attr->state is set to GARP_APPLICANT_VO, garp_attr_destroy() won't be called in last transmit event in garp_uninit_applicant(), the attr of applicant will be leaked. To fix this leak, iterate and free each attr of applicant before rerturning from garp_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/garp.c b/net/802/garp.c index 7f50d47470bd..8e19f51833d6 100644 --- a/net/802/garp.c +++ b/net/802/garp.c @@ -206,6 +206,19 @@ static void garp_attr_destroy(struct garp_applicant *app, struct garp_attr *attr kfree(attr); } +static void garp_attr_destroy_all(struct garp_applicant *app) +{ + struct rb_node *node, *next; + struct garp_attr *attr; + + for (node = rb_first(&app->gid); + next = node ? rb_next(node) : NULL, node != NULL; + node = next) { + attr = rb_entry(node, struct garp_attr, node); + garp_attr_destroy(app, attr); + } +} + static int garp_pdu_init(struct garp_applicant *app) { struct sk_buff *skb; @@ -612,6 +625,7 @@ void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl spin_lock_bh(&app->lock); garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU); + garp_attr_destroy_all(app); garp_pdu_queue(app); spin_unlock_bh(&app->lock);