Bug 2541238 (CVE-2026-97537)

Summary: CVE-2026-97537 kernel: scsi: qla2xxx: Fix queue teardown NULL dma_free and bitmap locking
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's qla2xxx driver. A local user could cause a Denial of Service (DoS) through a system crash during device queue teardown. This issue occurs when error handling paths fail to properly synchronize queue state and attempt to deallocate memory pointers that were never initialized.
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Description OSIDB Bzimport 2026-09-25 11:08:39 UTC
In the Linux kernel, the following vulnerability has been resolved:

scsi: qla2xxx: Fix queue teardown NULL dma_free and bitmap locking

qla25xx_free_req_que() and qla25xx_free_rsp_que() have two pre-existing
bugs exposed on the error path of qla25xx_create_{req,rsp}_que():

 1. When dma_alloc_coherent() fails during queue creation, the error
    path calls the free function with req->ring / rsp->ring still NULL
    (from kzalloc).  The unconditional dma_free_coherent() with a NULL
    cpu_addr is undefined behavior and can panic.

 2. The free functions clear req_qid_map / rsp_qid_map under vport_lock,
    but the create functions protect the same bitmaps with mq_lock.
    This provides no mutual exclusion.  Additionally, the create error
    path clears the bit and releases mq_lock before calling the free
    function, creating a window where another thread can allocate the
    same que_id and have its ha->req_q_map entry clobbered by the
    subsequent lockless NULL assignment in the free function.

Fix by:

 - Guarding dma_free_coherent() with a NULL check on the ring pointer.

 - Using mq_lock (the lock held by all creators) in the free functions
   to atomically NULL the map entry and clear the bitmap bit.

 - Removing the now-redundant clear_bit blocks from the create error
   paths since the free functions handle it atomically.