CVE-2022-49890 capabilities: fix potential memleak on error path from vfs_getxattr_alloc()
A memory leak in the Linux kernel capabilities subsystem can lead to resource exhaustion and denial of service.
- 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-2022-49890?
CVE-2022-49890 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:
capabilities: fix potential memleak on error path from vfs_getxattr_alloc()
In cap_inode_getsecurity(), we will use vfs_getxattr_alloc() to complete the memory allocation of tmpbuf, if we have completed the memory allocation of tmpbuf, but failed to call handler->get(...), there will be a memleak in below logic:
|-- ret = (int)vfs_getxattr_alloc(mnt_userns, ...) | /* ^^^ alloc for tmpbuf */ |-- value = krealloc(*xattr_value, error + 1, flags) | /* ^^^ alloc memory */ |-- error = handler->get(handler, ...) | /* error! */ |-- *xattr_value = value | /* xattr_value is &tmpbuf (memory leak!) */
So we will try to free(tmpbuf) after vfs_getxattr_alloc() fails to fix it.
[PM: subject line and backtrace tweaks]
Weakness: CWE-401
Which versions are affected by CVE-2022-49890?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49890?
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-2022-49890 being exploited?
There is no known exploitation of CVE-2022-49890 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49890, GHSA-wxgf-7f8j-hr6j, UBUNTU-CVE-2022-49890.