Use After Free Affecting kernel-rt-selftests-internal package, versions *


Severity

Recommended
medium

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.04% (6th percentile)

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  • Snyk IDSNYK-RHEL9-KERNELRTSELFTESTSINTERNAL-8259529
  • published23 Oct 2024
  • disclosed21 Oct 2024

Introduced: 21 Oct 2024

CVE-2024-50036  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:9 kernel-rt-selftests-internal.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-selftests-internal package and not the kernel-rt-selftests-internal package as distributed by RHEL. See How to fix? for RHEL:9 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

net: do not delay dst_entries_add() in dst_release()

dst_entries_add() uses per-cpu data that might be freed at netns dismantle from ip6_route_net_exit() calling dst_entries_destroy()

Before ip6_route_net_exit() can be called, we release all the dsts associated with this netns, via calls to dst_release(), which waits an rcu grace period before calling dst_destroy()

dst_entries_add() use in dst_destroy() is racy, because dst_entries_destroy() could have been called already.

Decrementing the number of dsts must happen sooner.

Notes:

  1. in CONFIG_XFRM case, dst_destroy() can call dst_release_immediate(child), this might also cause UAF if the child does not have DST_NOCOUNT set. IPSEC maintainers might take a look and see how to address this.

  2. There is also discussion about removing this count of dst, which might happen in future kernels.

CVSS Scores

version 3.1