Red Hat: CVE-2024-36891: kernel: maple_tree: fix mas_empty_area_rev() null pointer dereference (Multiple Advisories)

Red Hat: CVE-2024-36891: kernel: maple_tree: fix mas_empty_area_rev() null pointer dereference (Multiple Advisories)

Severity

5

CVSS

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

Published

05/30/2024

Created

12/06/2024

Added

12/05/2024

Modified

12/05/2024

Description

In the Linux kernel, the following vulnerability has been resolved: maple_tree: fix mas_empty_area_rev() null pointer dereference Currently the code calls mas_start() followed by mas_data_end() if the maple state is MA_START, but mas_start() may return with the maple state node == NULL.This will lead to a null pointer dereference when checking information in the NULL node, which is done in mas_data_end(). Avoid setting the offset if there is no node by waiting until after the maple state is checked for an empty or single entry state. A user could trigger the events to cause a kernel oops by unmapping all vmas to produce an empty maple tree, then mapping a vma that would cause the scenario described above.

Solution(s)

• redhat-upgrade-kernel
• redhat-upgrade-kernel-rt

References

• CVE-2024-36891
• RHSA-2024:9315