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

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
Linux / Linux	affected f3d55bd5b7b928ad82f8075d89c908702f3593ab before b32aa95843cac6b12c2c014d40fca18aef24a347; affected 1c00bb624cd084e2006520ad0edacaff0fb941c4 before 634ba3c97ec413cb10681c7b196db43ee461ecf4; affected 782b3e71c957991ac8ae53318bc369049d49bb53 before aa64464c8f4d2ab92f6d0b959a1e0767b829d787; affected 9e86dffd0b02594d2e7c60c6db9e889c0395414b before 098d54934814dd876963abfe751c3b1cf7fbe56a; affected 5e2cf333b7bd5d3e62595a44d598a254c697cd74 before 3f8d5e802d4cedd445f9a89be8c3fd2d0e99024b; affected 5e2cf333b7bd5d3e62595a44d598a254c697cd74 before cd2538e5af495b3c747e503db346470fc1ffc447; affected 5e2cf333b7bd5d3e62595a44d598a254c697cd74 before e332a12f65d8fed8cf63bedb4e9317bb872b9ac7; affected 5e2cf333b7bd5d3e62595a44d598a254c697cd74 before 151f66bb618d1fd0eeb84acb61b4a9fa5d8bb0fa; affected 7d808fe6af8409cf9f46ed2b10840e5788985e9b; affected 2cab058f2b147e0b7c01546ba00445e5701861f5; affected 91962e40ec3d26e291db230cd45b302da2aff200; affected 4.19.262 before 4.19.316; affected 5.4.220 before 5.4.278; affected 5.10.150 before 5.10.219; affected 5.15.75 before 5.15.161; affected 4.14.296 before 4.15; affected 5.19.17 before 5.20; affected 6.0.3 before 6.1
Linux / Linux	affected 6.1; unaffected 0 before 6.1; unaffected 4.19.316 through 4.19.; unaffected 5.4.278 through 5.4.; unaffected 5.10.219 through 5.10.; unaffected 5.15.161 through 5.15.; unaffected 6.1.94 through 6.1.; unaffected 6.6.34 through 6.6.; unaffected 6.9.5 through 6.9.; unaffected 6.10 through

Vendor / product

Versions

Linux / Linux

affected f3d55bd5b7b928ad82f8075d89c908702f3593ab before b32aa95843cac6b12c2c014d40fca18aef24a347; affected 1c00bb624cd084e2006520ad0edacaff0fb941c4 before 634ba3c97ec413cb10681c7b196db43ee461ecf4; affected 782b3e71c957991ac8ae53318bc369049d49bb53 before aa64464c8f4d2ab92f6d0b959a1e0767b829d787; affected 9e86dffd0b02594d2e7c60c6db9e889c0395414b before 098d54934814dd876963abfe751c3b1cf7fbe56a; affected 5e2cf333b7bd5d3e62595a44d598a254c697cd74 before 3f8d5e802d4cedd445f9a89be8c3fd2d0e99024b; affected 5e2cf333b7bd5d3e62595a44d598a254c697cd74 before cd2538e5af495b3c747e503db346470fc1ffc447; affected 5e2cf333b7bd5d3e62595a44d598a254c697cd74 before e332a12f65d8fed8cf63bedb4e9317bb872b9ac7; affected 5e2cf333b7bd5d3e62595a44d598a254c697cd74 before 151f66bb618d1fd0eeb84acb61b4a9fa5d8bb0fa; affected 7d808fe6af8409cf9f46ed2b10840e5788985e9b; affected 2cab058f2b147e0b7c01546ba00445e5701861f5; affected 91962e40ec3d26e291db230cd45b302da2aff200; affected 4.19.262 before 4.19.316; affected 5.4.220 before 5.4.278; affected 5.10.150 before 5.10.219; affected 5.15.75 before 5.15.161; affected 4.14.296 before 4.15; affected 5.19.17 before 5.20; affected 6.0.3 before 6.1

Linux / Linux

affected 6.1; unaffected 0 before 6.1; unaffected 4.19.316 through 4.19.*; unaffected 5.4.278 through 5.4.*; unaffected 5.10.219 through 5.10.*; unaffected 5.15.161 through 5.15.*; unaffected 6.1.94 through 6.1.*; unaffected 6.6.34 through 6.6.*; unaffected 6.9.5 through 6.9.*; unaffected 6.10 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.

CVE

No English description supplied.