CVE-2022-49636

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> vlan: fix memory leak in vlan_newlink()<br /> <br /> Blamed commit added back a bug I fixed in commit 9bbd917e0bec<br /> ("vlan: fix memory leak in vlan_dev_set_egress_priority")<br /> <br /> If a memory allocation fails in vlan_changelink() after other allocations<br /> succeeded, we need to call vlan_dev_free_egress_priority()<br /> to free all allocated memory because after a failed -&gt;newlink()<br /> we do not call any methods like ndo_uninit() or dev-&gt;priv_destructor().<br /> <br /> In following example, if the allocation for last element 2000:2001 fails,<br /> we need to free eight prior allocations:<br /> <br /> ip link add link dummy0 dummy0.100 type vlan id 100 \<br /> egress-qos-map 1:2 2:3 3:4 4:5 5:6 6:7 7:8 8:9 2000:2001<br /> <br /> syzbot report was:<br /> <br /> BUG: memory leak<br /> unreferenced object 0xffff888117bd1060 (size 32):<br /> comm "syz-executor408", pid 3759, jiffies 4294956555 (age 34.090s)<br /> hex dump (first 32 bytes):<br /> 09 00 00 00 00 a0 00 00 00 00 00 00 00 00 00 00 ................<br /> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................<br /> backtrace:<br /> [] kmalloc include/linux/slab.h:600 [inline]<br /> [] vlan_dev_set_egress_priority+0xed/0x170 net/8021q/vlan_dev.c:193<br /> [] vlan_changelink+0x178/0x1d0 net/8021q/vlan_netlink.c:128<br /> [] vlan_newlink+0x148/0x260 net/8021q/vlan_netlink.c:185<br /> [] rtnl_newlink_create net/core/rtnetlink.c:3363 [inline]<br /> [] __rtnl_newlink+0xa58/0xdc0 net/core/rtnetlink.c:3580<br /> [] rtnl_newlink+0x49/0x70 net/core/rtnetlink.c:3593<br /> [] rtnetlink_rcv_msg+0x21c/0x5c0 net/core/rtnetlink.c:6089<br /> [] netlink_rcv_skb+0x87/0x1d0 net/netlink/af_netlink.c:2501<br /> [] netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]<br /> [] netlink_unicast+0x397/0x4c0 net/netlink/af_netlink.c:1345<br /> [] netlink_sendmsg+0x396/0x710 net/netlink/af_netlink.c:1921<br /> [] sock_sendmsg_nosec net/socket.c:714 [inline]<br /> [] sock_sendmsg+0x56/0x80 net/socket.c:734<br /> [] ____sys_sendmsg+0x36c/0x390 net/socket.c:2488<br /> [] ___sys_sendmsg+0x8b/0xd0 net/socket.c:2542<br /> [] __sys_sendmsg net/socket.c:2571 [inline]<br /> [] __do_sys_sendmsg net/socket.c:2580 [inline]<br /> [] __se_sys_sendmsg net/socket.c:2578 [inline]<br /> [] __x64_sys_sendmsg+0x78/0xf0 net/socket.c:2578<br /> [] do_syscall_x64 arch/x86/entry/common.c:50 [inline]<br /> [] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80<br /> [] entry_SYSCALL_64_after_hwframe+0x46/0xb0