CVE-2021-47218
selinux: fix NULL-pointer dereference when hashtab allocation fails
Description
In the Linux kernel, the following vulnerability has been resolved: selinux: fix NULL-pointer dereference when hashtab allocation fails When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails.
INFO
Published Date :
April 10, 2024, 7:15 p.m.
Last Modified :
Jan. 14, 2025, 2:44 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the affected Linux packages.
- Reboot the system after updating.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47218.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47218 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47218
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-47218 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47218 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jan. 14, 2025
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NIST CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.8 up to (excluding) 5.10.82 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.5 *cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:* Changed Reference Type https://git.kernel.org/stable/c/83c8ab8503adf56bf68dafc7a382f4946c87da79 No Types Assigned https://git.kernel.org/stable/c/83c8ab8503adf56bf68dafc7a382f4946c87da79 Patch Changed Reference Type https://git.kernel.org/stable/c/83c8ab8503adf56bf68dafc7a382f4946c87da79 No Types Assigned https://git.kernel.org/stable/c/83c8ab8503adf56bf68dafc7a382f4946c87da79 Patch Changed Reference Type https://git.kernel.org/stable/c/b17dd53cac769dd13031b0ca34f90cc65e523fab No Types Assigned https://git.kernel.org/stable/c/b17dd53cac769dd13031b0ca34f90cc65e523fab Patch Changed Reference Type https://git.kernel.org/stable/c/b17dd53cac769dd13031b0ca34f90cc65e523fab No Types Assigned https://git.kernel.org/stable/c/b17dd53cac769dd13031b0ca34f90cc65e523fab Patch Changed Reference Type https://git.kernel.org/stable/c/dc27f3c5d10c58069672215787a96b4fae01818b No Types Assigned https://git.kernel.org/stable/c/dc27f3c5d10c58069672215787a96b4fae01818b Patch Changed Reference Type https://git.kernel.org/stable/c/dc27f3c5d10c58069672215787a96b4fae01818b No Types Assigned https://git.kernel.org/stable/c/dc27f3c5d10c58069672215787a96b4fae01818b Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/83c8ab8503adf56bf68dafc7a382f4946c87da79 Added Reference https://git.kernel.org/stable/c/b17dd53cac769dd13031b0ca34f90cc65e523fab Added Reference https://git.kernel.org/stable/c/dc27f3c5d10c58069672215787a96b4fae01818b -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 14, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 10, 2024
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: selinux: fix NULL-pointer dereference when hashtab allocation fails When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails. Added Reference kernel.org https://git.kernel.org/stable/c/b17dd53cac769dd13031b0ca34f90cc65e523fab [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/83c8ab8503adf56bf68dafc7a382f4946c87da79 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/dc27f3c5d10c58069672215787a96b4fae01818b [No types assigned]