Debian: CVE-2022-48821: linux -- security update

Debian: CVE-2022-48821: linux -- security update

Severity

4

CVSS

(AV:L/AC:M/Au:N/C:P/I:P/A:P)

Published

07/30/2024

Created

07/31/2024

Added

07/30/2024

Modified

07/31/2024

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.

Solution(s)

• debian-upgrade-linux

References

• https://attackerkb.com/topics/cve-2022-48821
• CVE - 2022-48821