CVE-2021-47624 net/sunrpc: fix reference count leaks in rpc_sysfs_xprt_state_change
A reference count leak in the Linux kernel's sunrpc module allows attackers to cause a denial of service by triggering an error path that fails to release resources.
- 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-2021-47624?
CVE-2021-47624 is a high-severity denial of service vulnerability in Linux kernel, published on 16 Jul 2024. 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/sunrpc: fix reference count leaks in rpc_sysfs_xprt_state_change
The refcount leak issues take place in an error handling path. When the 3rd argument buf doesn't match with "offline", "online" or "remove", the function simply returns -EINVAL and forgets to decrease the reference count of a rpc_xprt object and a rpc_xprt_switch object increased by rpc_sysfs_xprt_kobj_get_xprt() and rpc_sysfs_xprt_kobj_get_xprt_switch(), causing reference count leaks of both unused objects.
Fix this issue by jumping to the error handling path labelled with out_put when buf matches none of "offline", "online" or "remove".
Which versions are affected by CVE-2021-47624?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47624?
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-2021-47624 being exploited?
There is no known exploitation of CVE-2021-47624 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47624, GHSA-j53w-25v4-j86p, UBUNTU-CVE-2021-47624.