Red Hat Security Advisory: kernel security update

Important

A vulnerability was found in the Linux kernel's USB Video Class driver. A buffer for video frame data is allocated, which does not account for all of the frame formats contained in a video stream, leading to an out-of-bounds write when a stream includes frames with an undefined format. An attacker who is able to influence the format of video streams captured by a system's USB video device could exploit this flaw to alter system memory and potentially escalate their privileges or execute arbitrary code.

CWE-787 - Out-of-bounds Write

In the Linux kernel, the following vulnerability has been resolved: mm: fix NULL pointer dereference in alloc_pages_bulk_noprof We triggered a NULL pointer dereference for ac.preferred_zoneref->zone in alloc_pages_bulk_noprof() when the task is migrated between cpusets. When cpuset is enabled, in prepare_alloc_pages(), ac->nodemask may be &current->mems_allowed. when first_zones_zonelist() is called to find preferred_zoneref, the ac->nodemask may be modified concurrently if the task is migrated between different cpusets. Assuming we have 2 NUMA Node, when traversing Node1 in ac->zonelist, the nodemask is 2, and when traversing Node2 in ac->zonelist, the nodemask is 1. As a result, the ac->preferred_zoneref points to NULL zone. In alloc_pages_bulk_noprof(), for_each_zone_zonelist_nodemask() finds a allowable zone and calls zonelist_node_idx(ac.preferred_zoneref), leading to NULL pointer dereference. __alloc_pages_noprof() fixes this issue by checking NULL pointer in commit ea57485af8f4 ("mm, page_alloc: fix check for NULL preferred_zone") and commit df76cee6bbeb ("mm, page_alloc: remove redundant checks from alloc fastpath"). To fix it, check NULL pointer for preferred_zoneref->zone.

CWE-476 - NULL Pointer Dereference