CVE-2021-47295: In the Linux kernel, the following vulnerability has been resolved: net: sched: fix memory leak in tcindex_partial_destroy_work Syzbot reported memo...

Description

In the Linux kernel, the following vulnerability has been resolved: net: sched: fix memory leak in tcindex_partial_destroy_work Syzbot reported memory leak in tcindex_set_parms(). The problem was in non-freed perfect hash in tcindex_partial_destroy_work(). In tcindex_set_parms() new tcindex_data is allocated and some fields from old one are copied to new one, but not the perfect hash. Since tcindex_partial_destroy_work() is the destroy function for old tcindex_data, we need to free perfect hash to avoid memory leak.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.50%

70.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	>= 3.18, < 5.4.136	—
Linux	Linux Kernel	>= 5.5, < 5.10.54	—
Linux	Linux Kernel	>= 5.11, < 5.13.6	—
Linux	Linux Kernel	5.14	Rc1

References

Timeline

Published: May 21, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-47295?

In the Linux kernel, the following vulnerability has been resolved: net: sched: fix memory leak in tcindex_partial_destroy_work Syzbot reported memory leak in tcindex_set_parms(). The problem was in non-freed perfect hash in tcindex_partial_destroy_work(). In tcindex_set_parms() new tcindex_data is allocated and some fields from old one are copied to new one, but not the perfect hash. Since tcindex_partial_destroy_work() is the destroy function for old tcindex_data, we need to free perfect hash to avoid memory leak.

How severe is CVE-2021-47295?

CVE-2021-47295 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.50% probability of exploitation in the next 30 days.

How do I fix CVE-2021-47295?

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.