CVE-2024-39276

Medium

In the Linux kernel, the following vulnerability has been resolved: ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() Syzbot reports a warning as follows: ============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 Modules linked in: CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419 Call Trace: <TASK> ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327 [...] ============================================ This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage. So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.

Package Linux Kernel
Published 2024-06-25
Last modified 2025-03-24
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected versions

Linux kernel versions 4.19.14, 4.14.92, 4.20.1, 5.0 and later are affected. Fixed in 4.19.316, 5.4.278, 5.10.219, 5.15.161, 6.1.94, 6.6.34, 6.9.5, 6.10 and their respective stable series.

Affected from
≥ 4.19.14 ≥ 4.14.92 ≥ 4.20.1 ≥ 5.0
Fixed in
✓ 4.19.316 4.19.x ✓ 5.4.278 5.4.x ✓ 5.10.219 5.10.x ✓ 5.15.161 5.15.x ✓ 6.1.94 6.1.x ✓ 6.6.34 6.6.x ✓ 6.9.5 6.9.x ✓ 6.10

References

8 total
Showing 5 of 8 references View all on NVD

Frequently asked questions

  • What is CVE-2024-39276?

    CVE-2024-39276 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 4.19.14 onward and has been patched in 4.19.316, 5.4.278, 5.10.219 and others. CVE-2024-39276 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2024-39276?

    CVE-2024-39276 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N .

  • Is there a patch available for CVE-2024-39276?

    Yes. CVE-2024-39276 has been patched. Fixed versions include 4.19.316, 5.4.278, 5.10.219 and others. If you are running Linux kernel 4.19.14 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2024-39276 actively exploited?

    No. CVE-2024-39276 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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