Use After Free in Linux
CVE-2022-48801
In the Linux kernel, the following vulnerability has been resolved: iio: buffer: Fix file related error handling in IIO_BUFFER_GET_FD_IOCTL If we fail to copy the just created file descriptor to userland, we try to clean up by putting back 'fd' and freeing 'ib'. The code uses put_unused_fd() for the former which is wrong, as the file descriptor was already published by fd_install() which gets called internally by anon_inode_getfd(). This makes the error handling code leaving a half cleaned up file descriptor table around and a partially destructed 'file' object, allowing userland to play use-after-free tricks on us, by abusing the still usable fd and making the code operate on a dangling 'file->private_data' pointer. Instead of leaving the kernel in a partially corrupted state, don't attempt to explicitly clean up and leave this to the process exit path that'll release any still valid fds, including the one created by the previous call to anon_inode_getfd(). Simply return -EFAULT to indicate the error.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.003 (19.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Linux — versions f73f7f4da581875f9b1f2fb8ebd1ab15ed634488, 5.13, 0
- Linux Kernel — versions 5.17
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2022-48801?
- CVE-2022-48801 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.8/10. Published 2024-07-16.
- How severe is CVE-2022-48801?
- High severity. CVSS v3 base score is 7.8 out of 10.