CVE-2022-49853

In the Linux kernel, the following vulnerability has been resolved:

net: macvlan: fix memory leaks of macvlan_common_newlink

kmemleak reports memory leaks in macvlan_common_newlink, as follows:

ip link add link eth0 name .. type macvlan mode source macaddr add <MAC-ADDR>

kmemleak reports:

unreferenced object 0xffff8880109bb140 (size 64): comm "ip", pid 284, jiffies 4294986150 (age 430.108s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 b8 aa 5a 12 80 88 ff ff ..........Z..... 80 1b fa 0d 80 88 ff ff 1e ff ac af c7 c1 6b 6b ..............kk backtrace: [<ffffffff813e06a7>] kmem_cache_alloc_trace+0x1c7/0x300 [<ffffffff81b66025>] macvlan_hash_add_source+0x45/0xc0 [<ffffffff81b66a67>] macvlan_changelink_sources+0xd7/0x170 [<ffffffff81b6775c>] macvlan_common_newlink+0x38c/0x5a0 [<ffffffff81b6797e>] macvlan_newlink+0xe/0x20 [<ffffffff81d97f8f>] __rtnl_newlink+0x7af/0xa50 [<ffffffff81d98278>] rtnl_newlink+0x48/0x70 ...

In the scenario where the macvlan mode is configured as 'source', macvlan_changelink_sources() will be execured to reconfigure list of remote source mac addresses, at the same time, if register_netdevice() return an error, the resource generated by macvlan_changelink_sources() is not cleaned up.

Using this patch, in the case of an error, it will execute macvlan_flush_sources() to ensure that the resource is cleaned up.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.