Linux Kernel up to 6.18.19/6.19.9/7.0-rc4 bnxt_en bnxt_async_event_process memory corruption

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.18.19/6.19.9/7.0-rc4. This impacts the function bnxt_async_event_process of the component bnxt_en. Such manipulation leads to memory corruption. This vulnerability is documented as CVE-2026-31395. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.19/6.19.9/7.0-rc4. It has been rated as critical. Affected by this issue is the function bnxt_async_event_process of the component bnxt_en. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: bnxt_en: fix OOB access in DBG_BUF_PRODUCER async event handler The ASYNC_EVENT_CMPL_EVENT_ID_DBG_BUF_PRODUCER handler in bnxt_async_event_process() uses a firmware-supplied 'type' field directly as an index into bp->bs_trace[] without bounds validation. The 'type' field is a 16-bit value extracted from DMA-mapped completion ring memory that the NIC writes directly to host RAM. A malicious or compromised NIC can supply any value from 0 to 65535, causing an out-of-bounds access into kernel heap memory. The bnxt_bs_trace_check_wrap() call then dereferences bs_trace->magic_byte and writes to bs_trace->last_offset and bs_trace->wrapped, leading to kernel memory corruption or a crash. Fix by adding a bounds check and defining BNXT_TRACE_MAX as DBG_LOG_BUFFER_FLUSH_REQ_TYPE_ERR_QPC_TRACE + 1 to cover all currently defined firmware trace types (0x0 through 0xc).

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-31395 since 03/09/2026. The exploitation is known to be easy. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 04/03/2026).

Upgrading to version 6.18.20, 6.19.10 or 7.0-rc5 eliminates this vulnerability. Applying the patch 19aa416eed9e4aaf1bbe8da0f7bd9a9be31158c8/b7c7a275447c6d4bf4a36a134682e2e4e20efd4b/64dcbde7f8f870a4f2d9daf24ffb06f9748b5dd3 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5
• 6.19.6
• 6.19.7
• 6.19.8
• 6.19.9
• 7.0-rc1
• 7.0-rc2
• 7.0-rc3
• 7.0-rc4

License

• open-source

Website

• Vendor: https://www.kernel.org/

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