net: ena: fix MMIO read buffer leak on probe failure

Overview

In the Linux kernel, the following vulnerability has been resolved:

net: ena: fix MMIO read buffer leak on probe failure

ena_device_init() initializes the MMIO read mechanism with ena_com_mmio_reg_read_request_init(), which allocates a coherent DMA buffer for MMIO read responses.

The normal removal path releases this buffer through ena_com_mmio_reg_read_request_destroy(). However, if ena_probe() fails after ena_device_init() succeeds, the error path destroys the admin resources and eventually frees ena_dev without destroying the MMIO read request, leaving the coherent DMA buffer allocated.

Call ena_com_mmio_reg_read_request_destroy() in the probe error path before releasing the remaining device resources.

This issue was found by manual code inspection.

Affected

• Linux >= 1738cd3ed342294360d6a74d4e58800004bff854 < 7bd3e9a2d0c288e54f51df260d9433163f5fbc1e
• Linux >= 1738cd3ed342294360d6a74d4e58800004bff854 < 30ff01b4c7e419bb70f40f01dcd7f6af680808b3
• Linux >= 1738cd3ed342294360d6a74d4e58800004bff854 < 47785f9f638b064ce6e32e8e3b6f1ffd83849fc2
• Linux >= 1738cd3ed342294360d6a74d4e58800004bff854 < 9476b4468862927297c94c440863cd8ed1e7cc83
• Linux 4.9

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.