7.8

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.
Data is provided by the National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 4.7 < 4.14.257
Linux ≫ Linux Kernel Version >= 4.15 < 4.19.220
Linux ≫ Linux Kernel Version >= 4.20 < 5.4.164
Linux ≫ Linux Kernel Version >= 5.5 < 5.10.84
Linux ≫ Linux Kernel Version >= 5.11 < 5.15.7
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Type Source Score Percentile
EPSS FIRST.org 0.02% 0.03
CVSS Metriken
Source Base Score Exploit Score Impact Score Vector string
nvd@nist.gov 7.8 1.8 5.9
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-416 Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.