In the Linux kernel, the following vulnerability has been resolved: 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>]...
4.13.0-16.194.2.0-16.194.2.0-17.214.2.0-19.234.3.0-1.104.3.0-2.114.3.0-5.164.3.0-6.174.3.0-7.184.4.0-2.165.3.0-18.195.3.0-24.265.4.0-100.1135.4.0-104.1185.4.0-105.1195.4.0-107.1215.4.0-109.1235.4.0-110.1245.4.0-113.1275.4.0-117.132+108 more5.4.0-218.2383.11.0-12.195.13.0-19.195.15.0-100.1105.15.0-101.1115.15.0-102.1125.15.0-105.1155.15.0-106.1165.15.0-107.1175.15.0-112.1225.15.0-113.1235.15.0-116.126+65 more5.15.0-142.1526.5.0-9.96.11.0-8.85.19.0-1007.7~22.04.15.19.0-1009.9~22.04.15.19.0-1010.10~22.04.15.19.0-1011.11~22.04.15.19.0-1012.12~22.04.15.19.0-1013.13~22.04.15.19.0-1014.14~22.04.15.19.0-1015.15~22.04.15.3.0-1003.35.3.0-1008.95.3.0-1009.105.3.0-1010.115.4.0-1005.55.3.0-1003.35.3.0-1008.95.3.0-1009.105.3.0-1010.115.4.0-1005.55.4.0-1007.75.4.0-1008.85.4.0-1009.95.4.0-1011.115.4.0-1015.15+99 more5.4.0-1147.157Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:NA:HCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H