5.5

CVE-2024-39476: md/raid5: fix deadlock that raid5d() wait for itself to clear MD_SB_CHANGE_PENDING

Modified
AliasesUBUNTU-CVE-2024-39476DEBIAN-CVE-2024-39476
Published 05-07-2024Last modified 23-05-2026

Vulnerability summary

CVE-2024-39476 is a medium (CVSS 5.5) Improper Locking vulnerability in linux. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.18%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 17 · Related 10
DSA-5730-1MGASA-2024-0263MGASA-2024-0266RHSA-2024:5101RHSA-2024:5102RHSA-2024:5928

Timeline

  1. 05-07-2024
    PublishedVulnerability first disclosed.
  2. 23-05-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

7%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.18% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu115 products
  • linuxAll versions (No fix recorded) | < 5.4.0-181.201 | < 5.15.0-102.112
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.4.0-1124.134 | < 5.15.0-1057.63
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ f3d55bd5b7b928ad82f8075d89c908702f3593ab, < b32aa95843cac6b12c2c014d40fca18aef24a347 | ≥ 1c00bb624cd084e2006520ad0edacaff0fb941c4, < 634ba3c97ec413cb10681c7b196db43ee461ecf4 | ≥ 782b3e71c957991ac8ae53318bc369049d49bb53, < aa64464c8f4d2ab92f6d0b959a1e0767b829d787 | ≥ 9e86dffd0b02594d2e7c60c6db9e889c0395414b, < 098d54934814dd876963abfe751c3b1cf7fbe56a | ≥ 5e2cf333b7bd5d3e62595a44d598a254c697cd74, < 3f8d5e802d4cedd445f9a89be8c3fd2d0e99024b | ≥ 5e2cf333b7bd5d3e62595a44d598a254c697cd74, < cd2538e5af495b3c747e503db346470fc1ffc447 | ≥ 5e2cf333b7bd5d3e62595a44d598a254c697cd74, < e332a12f65d8fed8cf63bedb4e9317bb872b9ac7 | ≥ 5e2cf333b7bd5d3e62595a44d598a254c697cd74, < 151f66bb618d1fd0eeb84acb61b4a9fa5d8bb0fa | 7d808fe6af8409cf9f46ed2b10840e5788985e9b | 2cab058f2b147e0b7c01546ba00445e5701861f5 | 91962e40ec3d26e291db230cd45b302da2aff200 | ≥ 4.19.262, < 4.19.316 | ≥ 5.4.220, < 5.4.278 | ≥ 5.10.150, < 5.10.219 | ≥ 5.15.75, < 5.15.161 | ≥ 4.14.296, < 4.15 | ≥ 5.19.17, < 5.20 | ≥ 6.0.3, < 6.1 | 6.1
  • linux_kernel≥ 4.19, < 4.19.316 | ≥ 5.4, < 5.4.278 | ≥ 5.10, < 5.10.219 | ≥ 5.15, < 5.15.161 | ≥ 6.1, < 6.1.94 | ≥ 6.6, < 6.6.34 | ≥ 6.9, < 6.9.5
Debian1 product
  • linux< 6.1.94-1 | < 6.9.7-1

3 vendors · 118 products

References

13 links
Show all 13 references