Use After Free Affecting kernel-libbpf-static package, versions <0:6.1.79-99.164.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.04% (12th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNELLIBBPFSTATIC-7708327
  • published20 Aug 2024
  • disclosed3 Apr 2024

Introduced: 3 Apr 2024

CVE-2024-26689  (opens in a new tab)
CWE-416  (opens in a new tab)
First added by Snyk

How to fix?

Upgrade Amazon-Linux:2023 kernel-libbpf-static to version 0:6.1.79-99.164.amzn2023 or higher.
This issue was patched in ALAS2023-2024-549.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-libbpf-static package and not the kernel-libbpf-static package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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

ceph: prevent use-after-free in encode_cap_msg()

In fs/ceph/caps.c, in encode_cap_msg(), "use after free" error was caught by KASAN at this line - 'ceph_buffer_get(arg->xattr_buf);'. This implies before the refcount could be increment here, it was freed.

In same file, in "handle_cap_grant()" refcount is decremented by this line - 'ceph_buffer_put(ci->i_xattrs.blob);'. It appears that a race occurred and resource was freed by the latter line before the former line could increment it.

encode_cap_msg() is called by __send_cap() and __send_cap() is called by ceph_check_caps() after calling __prep_cap(). __prep_cap() is where arg->xattr_buf is assigned to ci->i_xattrs.blob. This is the spot where the refcount must be increased to prevent "use after free" error.

CVSS Scores

version 3.1