CVE-2026-97537 scsi: qla2xxx: Fix queue teardown NULL dma_free and bitmap locking
A NULL pointer dereference in the qla2xxx SCSI driver during queue teardown can cause a kernel panic, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97537?
CVE-2026-97537 is a vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-97537?
How do I fix CVE-2026-97537?
Apply the vendor's patch.
Is CVE-2026-97537 being exploited?
There is no known exploitation of CVE-2026-97537 in the wild and no public exploit code.
Sources
Also known as AZL-104723, BELL-CVE-2026-97537, DEBIAN-CVE-2026-97537, GHSA-46xm-fghf-r34f, UBUNTU-CVE-2026-97537.