CVE-2021-47541
HighIn 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.
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-416CVE-2021-47541 is a Use After Free vulnerability
What is Use After Free?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE
References
The following references provide additional information about CVE-2021-47541 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/676dc7d9b15bf8733233a2db1ec3f9091ab34275
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PatchKernel patch commithttps://git.kernel.org/stable/c/75917372eef0dbfb290ae45474314d35f97aea18
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PatchKernel patch commithttps://git.kernel.org/stable/c/addad7643142f500080417dd7272f49b7a185570
Frequently asked questions
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What is CVE-2021-47541?
CVE-2021-47541 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . CVE-2021-47541 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2021-47541?
CVE-2021-47541 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2021-47541?
No patch is currently available for CVE-2021-47541. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
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Is CVE-2021-47541 actively exploited?
No — CVE-2021-47541 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Use After Free (CWE-416)?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →