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authorEric Dumazet <edumazet@google.com>2022-07-08 15:11:53 +0000
committerDavid S. Miller <davem@davemloft.net>2022-07-09 12:26:59 +0100
commit72a0b329114b1caa8e69dfa7cdad1dd3c69b8602 (patch)
tree2745053a90a4ef2d8fb4f7050cc661ba2bf68bf7 /net/8021q
parent9c840d5f9aaef87e65db900bae21c70b059aba5f (diff)
vlan: fix memory leak in vlan_newlink()
Blamed commit added back a bug I fixed in commit 9bbd917e0bec ("vlan: fix memory leak in vlan_dev_set_egress_priority") If a memory allocation fails in vlan_changelink() after other allocations succeeded, we need to call vlan_dev_free_egress_priority() to free all allocated memory because after a failed ->newlink() we do not call any methods like ndo_uninit() or dev->priv_destructor(). In following example, if the allocation for last element 2000:2001 fails, we need to free eight prior allocations: ip link add link dummy0 dummy0.100 type vlan id 100 \ egress-qos-map 1:2 2:3 3:4 4:5 5:6 6:7 7:8 8:9 2000:2001 syzbot report was: BUG: memory leak unreferenced object 0xffff888117bd1060 (size 32): comm "syz-executor408", pid 3759, jiffies 4294956555 (age 34.090s) hex dump (first 32 bytes): 09 00 00 00 00 a0 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff83fc60ad>] kmalloc include/linux/slab.h:600 [inline] [<ffffffff83fc60ad>] vlan_dev_set_egress_priority+0xed/0x170 net/8021q/vlan_dev.c:193 [<ffffffff83fc6628>] vlan_changelink+0x178/0x1d0 net/8021q/vlan_netlink.c:128 [<ffffffff83fc67c8>] vlan_newlink+0x148/0x260 net/8021q/vlan_netlink.c:185 [<ffffffff838b1278>] rtnl_newlink_create net/core/rtnetlink.c:3363 [inline] [<ffffffff838b1278>] __rtnl_newlink+0xa58/0xdc0 net/core/rtnetlink.c:3580 [<ffffffff838b1629>] rtnl_newlink+0x49/0x70 net/core/rtnetlink.c:3593 [<ffffffff838ac66c>] rtnetlink_rcv_msg+0x21c/0x5c0 net/core/rtnetlink.c:6089 [<ffffffff839f9c37>] netlink_rcv_skb+0x87/0x1d0 net/netlink/af_netlink.c:2501 [<ffffffff839f8da7>] netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] [<ffffffff839f8da7>] netlink_unicast+0x397/0x4c0 net/netlink/af_netlink.c:1345 [<ffffffff839f9266>] netlink_sendmsg+0x396/0x710 net/netlink/af_netlink.c:1921 [<ffffffff8384dbf6>] sock_sendmsg_nosec net/socket.c:714 [inline] [<ffffffff8384dbf6>] sock_sendmsg+0x56/0x80 net/socket.c:734 [<ffffffff8384e15c>] ____sys_sendmsg+0x36c/0x390 net/socket.c:2488 [<ffffffff838523cb>] ___sys_sendmsg+0x8b/0xd0 net/socket.c:2542 [<ffffffff838525b8>] __sys_sendmsg net/socket.c:2571 [inline] [<ffffffff838525b8>] __do_sys_sendmsg net/socket.c:2580 [inline] [<ffffffff838525b8>] __se_sys_sendmsg net/socket.c:2578 [inline] [<ffffffff838525b8>] __x64_sys_sendmsg+0x78/0xf0 net/socket.c:2578 [<ffffffff845ad8d5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff845ad8d5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff8460006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fixes: 37aa50c539bc ("vlan: introduce vlan_dev_free_egress_priority") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Xin Long <lucien.xin@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/8021q')
-rw-r--r--net/8021q/vlan_netlink.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c
index 53b1955b027f..214532173536 100644
--- a/net/8021q/vlan_netlink.c
+++ b/net/8021q/vlan_netlink.c
@@ -182,10 +182,14 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev,
else if (dev->mtu > max_mtu)
return -EINVAL;
+ /* Note: If this initial vlan_changelink() fails, we need
+ * to call vlan_dev_free_egress_priority() to free memory.
+ */
err = vlan_changelink(dev, tb, data, extack);
- if (err)
- return err;
- err = register_vlan_dev(dev, extack);
+
+ if (!err)
+ err = register_vlan_dev(dev, extack);
+
if (err)
vlan_dev_free_egress_priority(dev);
return err;