CVE-2024-39476

Medium

In the Linux kernel, the following vulnerability has been resolved: md/raid5: fix deadlock that raid5d() wait for itself to clear MD_SB_CHANGE_PENDING Xiao reported that lvm2 test lvconvert-raid-takeover.sh can hang with small possibility, the root cause is exactly the same as commit bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"") However, Dan reported another hang after that, and junxiao investigated the problem and found out that this is caused by plugged bio can't issue from raid5d(). Current implementation in raid5d() has a weird dependence: 1) md_check_recovery() from raid5d() must hold 'reconfig_mutex' to clear MD_SB_CHANGE_PENDING; 2) raid5d() handles IO in a deadloop, until all IO are issued; 3) IO from raid5d() must wait for MD_SB_CHANGE_PENDING to be cleared; This behaviour is introduce before v2.6, and for consequence, if other context hold 'reconfig_mutex', and md_check_recovery() can't update super_block, then raid5d() will waste one cpu 100% by the deadloop, until 'reconfig_mutex' is released. Refer to the implementation from raid1 and raid10, fix this problem by skipping issue IO if MD_SB_CHANGE_PENDING is still set after md_check_recovery(), daemon thread will be woken up when 'reconfig_mutex' is released. Meanwhile, the hang problem will be fixed as well.

Package Linux Kernel
Published 2024-07-05
Last modified 2024-11-21
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
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-667

CVE-2024-39476 is a Improper Locking vulnerability

What is Improper Locking?

The product does not properly acquire or release a lock, which can lead to unexpected behaviour. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.19.262, 5.4.220, 5.10.150, 5.15.75, 4.14.296, 5.19.17, 6.0.3, 6.1 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
≥ 4.19.262 ≥ 5.4.220 ≥ 5.10.150 ≥ 5.15.75 ≥ 4.14.296 ≥ 5.19.17 ≥ 6.0.3 ≥ 6.1
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-2024-39476?

    CVE-2024-39476 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Improper Locking flaw (CWE-667) . It affects Linux kernel versions from 4.19.262 onward and has been patched in 4.19.316, 5.4.278, 5.10.219 and others. CVE-2024-39476 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2024-39476?

    CVE-2024-39476 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:N/I:N/A:H .

  • Is there a patch available for CVE-2024-39476?

    Yes. CVE-2024-39476 has been patched. Fixed versions include 4.19.316, 5.4.278, 5.10.219 and others. If you are running Linux kernel 4.19.262 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2024-39476 actively exploited?

    No. CVE-2024-39476 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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