CVE-2021-47542: In the Linux kernel, the following vulnerability has been resolved: net: qlogic: qlcnic: Fix a NULL pointer dereference in qlcnic_83xx_add_rings() In qlcnic

In the Linux kernel, the following vulnerability has been resolved: net: qlogic: qlcnic: Fix a NULL pointer dereference in qlcnic_83xx_add_rings() In qlcnic_8

In the Linux kernel, the following vulnerability has been resolved: net: qlogic: qlcnic: Fix a NULL pointer dereference in qlcnic_83xx_add_rings() In qlcnic_83xx_add_rings(), the indirect function of ahw->hw_ops->alloc_mbx_args will be called to allocate memory for cmd.req.arg, and there is a dereference of it in qlcnic_83xx_add_rings(), which could lead to a NULL pointer dereference on failure of the indirect function like qlcnic_83xx_alloc_mbx_args(). Fix this bug by adding a check of alloc_mbx_args(), this patch imitates the logic of mbx_cmd()'s failure handling. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_QLCNIC=m show no new warnings, and our static analyzer no longer warns about this code.

Description from the National Vulnerability Database, published by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

What it means for a small business

Linux is on the computers, phones or browsers your team uses every day. Turn on automatic updates and restart: most of these fixes only take effect after a restart.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.25%, higher than 16% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored November 10, 2026, updated daily.

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Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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