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CVE PROGRAM SOURCE RECORDUnscored

CVE-2024-39476

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

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Status
Published
Published
Updated
Assigning organization
Linux

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • f3d55bd5b7b928ad82f8075d89c908702f3593ab to < b32aa95843cac6b12c2c014d40fca18aef24a347affected
  • 1c00bb624cd084e2006520ad0edacaff0fb941c4 to < 634ba3c97ec413cb10681c7b196db43ee461ecf4affected
  • 782b3e71c957991ac8ae53318bc369049d49bb53 to < aa64464c8f4d2ab92f6d0b959a1e0767b829d787affected
  • 9e86dffd0b02594d2e7c60c6db9e889c0395414b to < 098d54934814dd876963abfe751c3b1cf7fbe56aaffected
  • 5e2cf333b7bd5d3e62595a44d598a254c697cd74 to < 3f8d5e802d4cedd445f9a89be8c3fd2d0e99024baffected
  • 5e2cf333b7bd5d3e62595a44d598a254c697cd74 to < cd2538e5af495b3c747e503db346470fc1ffc447affected
  • 5e2cf333b7bd5d3e62595a44d598a254c697cd74 to < e332a12f65d8fed8cf63bedb4e9317bb872b9ac7affected
  • 5e2cf333b7bd5d3e62595a44d598a254c697cd74 to < 151f66bb618d1fd0eeb84acb61b4a9fa5d8bb0faaffected
  • 7d808fe6af8409cf9f46ed2b10840e5788985e9baffected
  • 2cab058f2b147e0b7c01546ba00445e5701861f5affected
  • 91962e40ec3d26e291db230cd45b302da2aff200affected
  • 4.19.262 to < 4.19.316affected
  • 5.4.220 to < 5.4.278affected
  • 5.10.150 to < 5.10.219affected
  • 5.15.75 to < 5.15.161affected
  • 4.14.296 to < 4.15affected
  • 5.19.17 to < 5.20affected
  • 6.0.3 to < 6.1affected

Linux Linux

Default version status: affected

  • 6.1affected
  • 0 to < 6.1unaffected
  • 4.19.316 to ≤ 4.19.*unaffected
  • 5.4.278 to ≤ 5.4.*unaffected
  • 5.10.219 to ≤ 5.10.*unaffected
  • 5.15.161 to ≤ 5.15.*unaffected
  • 6.1.94 to ≤ 6.1.*unaffected
  • 6.6.34 to ≤ 6.6.*unaffected
  • 6.9.5 to ≤ 6.9.*unaffected
  • 6.10 to ≤ *unaffected

References