CVE-2021-47541: In the Linux kernel, the following vulnerability has been resolved: net/mlx4_en: Fix an use-after-free bug in mlx4_en_try_alloc_resources() In mlx4_...

Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx4_en: Fix an use-after-free bug in mlx4_en_try_alloc_resources() In mlx4_en_try_alloc_resources(), mlx4_en_copy_priv() is called and tmp->tx_cq will be freed on the error path of mlx4_en_copy_priv(). After that mlx4_en_alloc_resources() is called and there is a dereference of &tmp->tx_cq[t][i] in mlx4_en_alloc_resources(), which could lead to a use after free problem on failure of mlx4_en_copy_priv(). Fix this bug by adding a check of mlx4_en_copy_priv() 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_MLX4_EN=m show no new warnings, and our static analyzer no longer warns about this code.

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

0.29%

21.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 4.7, < 4.14.257
Linux	Linux Kernel	>= 4.15, < 4.19.220
Linux	Linux Kernel	>= 4.20, < 5.4.164
Linux	Linux Kernel	>= 5.5, < 5.10.84
Linux	Linux Kernel	>= 5.11, < 5.15.7

References

Timeline

Published: May 24, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-47541?

In the Linux kernel, the following vulnerability has been resolved: net/mlx4_en: Fix an use-after-free bug in mlx4_en_try_alloc_resources() In mlx4_en_try_alloc_resources(), mlx4_en_copy_priv() is called and tmp->tx_cq will be freed on the error path of mlx4_en_copy_priv(). After that mlx4_en_alloc_resources() is called and there is a dereference of &tmp->tx_cq[t][i] in mlx4_en_alloc_resources(), which could lead to a use after free problem on failure of mlx4_en_copy_priv(). Fix this bug by adding a check of mlx4_en_copy_priv() 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_MLX4_EN=m show no new warnings, and our static analyzer no longer warns about this code.

How severe is CVE-2021-47541?

CVE-2021-47541 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.29% probability of exploitation in the next 30 days.

How do I fix CVE-2021-47541?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.