Overview
About vulnerability
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():
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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.
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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:
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Guarding dma_free_coherent() with a NULL check on the ring pointer.
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Using mq_lock (the lock held by all creators) in the free functions to atomically NULL the map entry and clear the bitmap bit.
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Removing the now-redundant clear_bit blocks from the create error paths since the free functions handle it atomically.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.10.259 (+19 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 13 | Planned | — |