Description

In the Linux kernel, the following vulnerability has been resolved: selinux: fix overlayfs mmap() and mprotect() access checks The existing SELinux security model for overlayfs is to allow access if the current task is able to access the top level file (the "user" file) and the mounter's credentials are sufficient to access the lower level file (the "backing" file). Unfortunately, the current code does not properly enforce these access controls for both mmap() and mprotect() operations on overlayfs filesystems. This patch makes use of the newly created security_mmap_backing_file() LSM hook to provide the missing backing file enforcement for mmap() operations, and leverages the backing file API and new LSM blob to provide the necessary information to properly enforce the mprotect() access controls.

Affected Products 1

References 2

• git.kernel.org https://git.kernel.org/stable/c/82544d36b1729153c8aeb179e84750f0c085d3b1
  Patch
• git.kernel.org https://git.kernel.org/stable/c/cd0e707a927a70cdfd8bc5a512a9719a87f5ed51
  Patch

Remediation

• git.kernel.org https://git.kernel.org/stable/c/82544d36b1729153c8aeb179e84750f0c085d3b1
  Patch
• git.kernel.org https://git.kernel.org/stable/c/cd0e707a927a70cdfd8bc5a512a9719a87f5ed51
  Patch