CVE-2024-56780

Summary

In the Linux kernel, the following vulnerability has been resolved:

quota: flush quota_release_work upon quota writeback

One of the paths quota writeback is called from is:

freeze_super() sync_filesystem() ext4_sync_fs() dquot_writeback_dquots()

Since we currently don't always flush the quota_release_work queue in this path, we can end up with the following race:

  1. dquot are added to releasing_dquots list during regular operations.
  2. FS Freeze starts, however, this does not flush the quota_release_work queue.
  3. Freeze completes.
  4. Kernel eventually tries to flush the workqueue while FS is frozen which hits a WARN_ON since transaction gets started during frozen state:

ext4_journal_check_start+0x28/0x110 [ext4] (unreliable) __ext4_journal_start_sb+0x64/0x1c0 [ext4] ext4_release_dquot+0x90/0x1d0 [ext4] quota_release_workfn+0x43c/0x4d0

Which is the following line:

WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);

Which ultimately results in generic/390 failing due to dmesg noise. This was detected on powerpc machine 15 cores.

To avoid this, make sure to flush the workqueue during dquot_writeback_dquots() so we dont have any pending workitems after freeze.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxd40c192e119892799dd4ddf94f5cea6fa93775ef < a5abba5e0e586e258ded3e798fe5f69c66fec198affected
LinuxLinux86d89987f0998c98f57d641e308b40452a994045 < 6f3821acd7c3143145999248087de5fb4b48cf26affected
LinuxLinux89602de9a2d7080b7a4029d5c1bf8f78d295ff5f < ab6cfcf8ed2c7496f55d020b65b1d8cd55d9a2cbaffected
LinuxLinux3027e200dd58d5b437f16634dbbd355b29ffe0a6 < 3e6ff207cd5bd924ad94cd1a7c633bcdac0ba1cbaffected
LinuxLinuxdabc8b20756601b9e1cc85a81d47d3f98ed4d13a < bcacb52a985f1b6d280f698a470b873dfe52728aaffected
LinuxLinuxdabc8b20756601b9e1cc85a81d47d3f98ed4d13a < 8ea87e34792258825d290f4dc5216276e91cb224affected
LinuxLinuxdabc8b20756601b9e1cc85a81d47d3f98ed4d13a < ac6f420291b3fee1113f21d612fa88b628afab5baffected
LinuxLinuxf3e9a2bbdeb8987508dd6bb2b701dea911d4daecaffected
LinuxLinux903fc5d8cb48b0d2de7095ef40e39fd32bb27bd0affected
LinuxLinux31bed65eecbc5ce57592cfe31947eaa64e3d678eaffected
LinuxLinux5.4.257 < 5.4.287affected
LinuxLinux5.10.195 < 5.10.231affected
LinuxLinux5.15.132 < 5.15.174affected
LinuxLinux6.1.53 < 6.1.120affected
LinuxLinux4.19.295 < 4.20affected
LinuxLinux6.4.16 < 6.5affected
LinuxLinux6.5.3 < 6.6affected
LinuxLinux6.6affected
LinuxLinux0 < 6.6unaffected
LinuxLinux5.4.287 <= 5.4.*unaffected
LinuxLinux5.10.231 <= 5.10.*unaffected
LinuxLinux5.15.174 <= 5.15.*unaffected
LinuxLinux6.1.120 <= 6.1.*unaffected
LinuxLinux6.6.64 <= 6.6.*unaffected
LinuxLinux6.12.4 <= 6.12.*unaffected
LinuxLinux6.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References