Double Free Affecting kernel-libbpf package, versions <0:6.1.115-126.197.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.04% (6th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNELLIBBPF-8662122
  • published25 Jan 2025
  • disclosed21 Oct 2024

Introduced: 21 Oct 2024

CVE-2024-49983  (opens in a new tab)
CWE-415  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-libbpf to version 0:6.1.115-126.197.amzn2023 or higher.
This issue was patched in ALAS2023-2025-794.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-libbpf package and not the kernel-libbpf 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:

ext4: drop ppath from ext4_ext_replay_update_ex() to avoid double-free

When calling ext4_force_split_extent_at() in ext4_ext_replay_update_ex(), the 'ppath' is updated but it is the 'path' that is freed, thus potentially triggering a double-free in the following process:

ext4_ext_replay_update_ex ppath = path ext4_force_split_extent_at(&ppath) ext4_split_extent_at ext4_ext_insert_extent ext4_ext_create_new_leaf ext4_ext_grow_indepth ext4_find_extent if (depth > path[0].p_maxdepth) kfree(path) ---> path First freed *orig_path = path = NULL ---> null ppath kfree(path) ---> path double-free !!!

So drop the unnecessary ppath and use path directly to avoid this problem. And use ext4_find_extent() directly to update path, avoiding unnecessary memory allocation and freeing. Also, propagate the error returned by ext4_find_extent() instead of using strange error codes.

CVSS Scores

version 3.1