7.8

CVE-2021-47541: net/mlx4_en: Fix an use-after-free bug in mlx4_en_try_alloc_resources()

Modified
AliasesUBUNTU-CVE-2021-47541DEBIAN-CVE-2021-47541
Published 24-05-2024Last modified 05-08-2026

Vulnerability summary

CVE-2021-47541 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 22.1% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.29%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 11 · Related 11
SUSE-SU-2024:1979-1SUSE-SU-2024:1983-1SUSE-SU-2024:2008-1SUSE-SU-2024:2010-1SUSE-SU-2024:2011-1SUSE-SU-2024:2019-1

Timeline

  1. 24-05-2024
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.29%

Chance of exploitation in the next 30 days

Percentile

22%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.29% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu87 products
  • linux< 4.15.0-169.177 | < 5.4.0-100.113
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.15.0-1121.129 | < 5.4.0-1066.69
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ ec25bc04ed8e12947738468cbe2191f1529f9e39, < be12572c5ddc8ad7453bada4eec8fa46967dc757 | ≥ ec25bc04ed8e12947738468cbe2191f1529f9e39, < 676dc7d9b15bf8733233a2db1ec3f9091ab34275 | ≥ ec25bc04ed8e12947738468cbe2191f1529f9e39, < e461a9816a1ac5b4aeb61621b817225b61e46a68 | ≥ ec25bc04ed8e12947738468cbe2191f1529f9e39, < f1d43efa59f1edd3e7eca0e94559b4c6b1cd4e2b | ≥ ec25bc04ed8e12947738468cbe2191f1529f9e39, < 75917372eef0dbfb290ae45474314d35f97aea18 | ≥ ec25bc04ed8e12947738468cbe2191f1529f9e39, < addad7643142f500080417dd7272f49b7a185570 | 4.7
  • linux_kernel≥ 4.7, < 4.14.257 | ≥ 4.15, < 4.19.220 | ≥ 4.20, < 5.4.164 | ≥ 5.5, < 5.10.84 | ≥ 5.11, < 5.15.7
Debian1 product
  • linux< 5.15.15-1

3 vendors · 90 products

References

10 links