CVE-2022-48821: In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: avoid double fput() on failed usercopy If the copy back to userla...

Description

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: avoid double fput() on failed usercopy If the copy back to userland fails for the FASTRPC_IOCTL_ALLOC_DMA_BUFF ioctl(), we shouldn't assume that 'buf->dmabuf' is still valid. In fact, dma_buf_fd() called fd_install() before, i.e. "consumed" one reference, leaving us with none. Calling dma_buf_put() will therefore put a reference we no longer own, leading to a valid file descritor table entry for an already released 'file' object which is a straight use-after-free. Simply avoid calling dma_buf_put() and rely on the process exit code to do the necessary cleanup, if needed, i.e. if the file descriptor is still valid.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.27%

18.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	>= 5.1, < 5.4.180	—
Linux	Linux Kernel	>= 5.5, < 5.10.101	—
Linux	Linux Kernel	>= 5.11, < 5.15.24	—
Linux	Linux Kernel	>= 5.16, < 5.16.10	—
Linux	Linux Kernel	5.17	Rc1

References

Timeline

Published: Jul 16, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2022-48821?

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: avoid double fput() on failed usercopy If the copy back to userland fails for the FASTRPC_IOCTL_ALLOC_DMA_BUFF ioctl(), we shouldn't assume that 'buf->dmabuf' is still valid. In fact, dma_buf_fd() called fd_install() before, i.e. "consumed" one reference, leaving us with none. Calling dma_buf_put() will therefore put a reference we no longer own, leading to a valid file descritor table entry for an already released 'file' object which is a straight use-after-free. Simply avoid calling dma_buf_put() and rely on the process exit code to do the necessary cleanup, if needed, i.e. if the file descriptor is still valid.

How severe is CVE-2022-48821?

CVE-2022-48821 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.27% probability of exploitation in the next 30 days.

How do I fix CVE-2022-48821?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.