CVE-2022-49853 net: macvlan: fix memory leaks of macvlan_common_newlink
A memory leak in the Linux kernel macvlan driver allows local attackers to exhaust system memory by triggering specific network configuration errors.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-49853?
CVE-2022-49853 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 May 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-401
Which versions are affected by CVE-2022-49853?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49853?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-49853 being exploited?
There is no known exploitation of CVE-2022-49853 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49853, GHSA-rc8q-6743-jh4w, UBUNTU-CVE-2022-49853.