CVE-2022-50288: qlcnic: prevent ->dcb use-after-free on qlcnic_dcb_enable() failure

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-15 · updated 2026-06-17
Weakness: CWE-416

Description

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.

Affected products

Linux kernel: from 3.14 before 4.14.303; from 4.15 before 4.19.270; from 4.20 before 5.4.229; from 5.5 before 5.10.163; from 5.11 before 5.15.87; from 5.16 before 6.0.19 — fixed in 4.14.303, 4.19.270, 5.10.163, 5.15.87, 5.4.229, 6.0.19

How to fix

Upgrade to a fixed version: Linux kernel 4.14.303, 4.19.270, 5.10.163, 5.15.87. Check the vendor advisory for mitigations.

References

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