CVE-2022-50288

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

qlcnic: prevent ->dcb use-after-free on qlcnic_dcb_enable() failure

adapter->dcb would get silently freed inside qlcnic_dcb_enable() in case qlcnic_dcb_attach() would return an error, which always happens under OOM conditions. This would lead to use-after-free because both of the existing callers invoke qlcnic_dcb_get_info() on the obtained pointer, which is potentially freed at that point.

Propagate errors from qlcnic_dcb_enable(), and instead free the dcb pointer at callsite using qlcnic_dcb_free(). This also removes the now unused qlcnic_clear_dcb_ops() helper, which was a simple wrapper around kfree() also causing memory leaks for partially initialized dcb.

Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool.

This issue was caused by a use-after-free in the qlcnic driver when qlcnic_dcb_enable() failed under out-of-memory conditions. The freed dcb structure could still be accessed by subsequent calls, leading to a potential kernel crash. Exploitation beyond denial of service is unlikely, and the bug only affects systems using QLogic QLCNIC adapters with DCB support enabled.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.