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

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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.

Signed-off-by: Nilesh Javali <njavali@marvell.com>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Link: https://patch.msgid.link/20260723050413.3897522-41-njavali@marvell.com
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>

...

This commit is contained in:

Nilesh Javali 2026-07-23 10:33:57 +05:30 • committed by Martin K. Petersen (Oracle)

parent 0267b4fbab

commit 34a40e0dff

1 changed files with 12 additions and 16 deletions

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drivers/scsi/qla2xxx/qla_mid.c

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