Bug 2423597 (CVE-2025-68324)

Summary: CVE-2025-68324 kernel: scsi: imm: Fix use-after-free bug caused by unfinished delayed work
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2025-12-18 16:01:33 UTC
In the Linux kernel, the following vulnerability has been resolved:

scsi: imm: Fix use-after-free bug caused by unfinished delayed work

The delayed work item 'imm_tq' is initialized in imm_attach() and
scheduled via imm_queuecommand() for processing SCSI commands.  When the
IMM parallel port SCSI host adapter is detached through imm_detach(),
the imm_struct device instance is deallocated.

However, the delayed work might still be pending or executing
when imm_detach() is called, leading to use-after-free bugs
when the work function imm_interrupt() accesses the already
freed imm_struct memory.

The race condition can occur as follows:

CPU 0(detach thread)   | CPU 1
                       | imm_queuecommand()
                       |   imm_queuecommand_lck()
imm_detach()           |     schedule_delayed_work()
  kfree(dev) //FREE    | imm_interrupt()
                       |   dev = container_of(...) //USE
                           dev-> //USE

Add disable_delayed_work_sync() in imm_detach() to guarantee proper
cancellation of the delayed work item before imm_struct is deallocated.