# CVE-2021-47542: linux: In the Linux kernel, the following vulnerability has been resolved:  net: qlogic: qlcnic: Fix a NULL pointer derefere...

CVE-2021-47542 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47542, released May 24, 2024. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-47542
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0025
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 24, 2024

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 5.15.15-1 | [DEBIAN-CVE-2021-47542](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47542.md) | May 24, 2024 |
| Linux | linux Debian 13.5 (trixie) | 5.15.15-1 | [DEBIAN-CVE-2021-47542](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47542.md) | May 24, 2024 |
| Linux | linux Debian 14 | 5.15.15-1 | [DEBIAN-CVE-2021-47542](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47542.md) | May 24, 2024 |

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