CVE-2021-47542

MEDIUM
Published May 24, 2024 Modified Nov 21, 2024 CWE-476

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.

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CVSS v3.1 Score

5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

https://git.kernel.org/stable/c/15fa12c119f869173f9b710cbe6a4a14071d2105 https://git.kernel.org/stable/c/3a061d54e260b701b538873b43e399d9b8b83e03 https://git.kernel.org/stable/c/550658a2d61e4eaf522c8ebc7fad76dc376bfb45 https://git.kernel.org/stable/c/57af54a56024435d83e44c78449513b414eb6edf https://git.kernel.org/stable/c/b4f217d6fcc00c3fdc0921a7691f30be7490b073 https://git.kernel.org/stable/c/bbeb0325a7460ebf1e03f5e0bfc5c652fba9519f https://git.kernel.org/stable/c/c5ef33c1489b2cd74368057fa00b5d2183bb5853 https://git.kernel.org/stable/c/e2dabc4f7e7b60299c20a36d6a7b24ed9bf8e572 https://git.kernel.org/stable/c/15fa12c119f869173f9b710cbe6a4a14071d2105 https://git.kernel.org/stable/c/3a061d54e260b701b538873b43e399d9b8b83e03 https://git.kernel.org/stable/c/550658a2d61e4eaf522c8ebc7fad76dc376bfb45 https://git.kernel.org/stable/c/57af54a56024435d83e44c78449513b414eb6edf https://git.kernel.org/stable/c/b4f217d6fcc00c3fdc0921a7691f30be7490b073 https://git.kernel.org/stable/c/bbeb0325a7460ebf1e03f5e0bfc5c652fba9519f https://git.kernel.org/stable/c/c5ef33c1489b2cd74368057fa00b5d2183bb5853 https://git.kernel.org/stable/c/e2dabc4f7e7b60299c20a36d6a7b24ed9bf8e572

Frequently Asked Questions

What is 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_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. It has a CVSS v3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2021-47542? +
CVE-2021-47542 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2021-47542? +
CVE-2021-47542 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2021-47542? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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