CVE-2024-26627

Summary

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

scsi: core: Move scsi_host_busy() out of host lock for waking up EH handler

Inside scsi_eh_wakeup(), scsi_host_busy() is called & checked with host lock every time for deciding if error handler kthread needs to be waken up.

This can be too heavy in case of recovery, such as:

  • N hardware queues

  • queue depth is M for each hardware queue

  • each scsi_host_busy() iterates over (N * M) tag/requests

If recovery is triggered in case that all requests are in-flight, each scsi_eh_wakeup() is strictly serialized, when scsi_eh_wakeup() is called for the last in-flight request, scsi_host_busy() has been run for (N * M -

  1. times, and request has been iterated for (N*M - 1) * (N * M) times.

If both N and M are big enough, hard lockup can be triggered on acquiring host lock, and it is observed on mpi3mr(128 hw queues, queue depth 8169).

Fix the issue by calling scsi_host_busy() outside the host lock. We don't need the host lock for getting busy count because host the lock never covers that.

[mkp: Drop unnecessary 'busy' variables pointed out by Bart]

Affected Software

VendorProductVersion RangeStatus
LinuxLinux6eb045e092efefafc6687409a6fa6d1dabf0fb69 < f5944853f7a961fedc1227dc8f60393f8936d37caffected
LinuxLinux6eb045e092efefafc6687409a6fa6d1dabf0fb69 < d37c1c81419fdef66ebd0747cf76fb8b7d979059affected
LinuxLinux6eb045e092efefafc6687409a6fa6d1dabf0fb69 < db6338f45971b4285ea368432a84033690eaf53caffected
LinuxLinux6eb045e092efefafc6687409a6fa6d1dabf0fb69 < 65ead8468c21c2676d4d06f50b46beffdea69df1affected
LinuxLinux6eb045e092efefafc6687409a6fa6d1dabf0fb69 < 07e3ca0f17f579491b5f54e9ed05173d6c1d6fcbaffected
LinuxLinux6eb045e092efefafc6687409a6fa6d1dabf0fb69 < 4373534a9850627a2695317944898eb1283a2db0affected
LinuxLinux5.5affected
LinuxLinux0 < 5.5unaffected
LinuxLinux5.10.210 <= 5.10.*unaffected
LinuxLinux5.15.149 <= 5.15.*unaffected
LinuxLinux6.1.77 <= 6.1.*unaffected
LinuxLinux6.6.16 <= 6.6.*unaffected
LinuxLinux6.7.4 <= 6.7.*unaffected
LinuxLinux6.8 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

CVE Program Container

Additional References

References