CVE-2021-47249

Medium

In the Linux kernel, the following vulnerability has been resolved: net: rds: fix memory leak in rds_recvmsg Syzbot reported memory leak in rds. The problem was in unputted refcount in case of error. int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, int msg_flags) { ... if (!rds_next_incoming(rs, &inc)) { ... } After this "if" inc refcount incremented and if (rds_cmsg_recv(inc, msg, rs)) { ret = -EFAULT; goto out; } ... out: return ret; } in case of rds_cmsg_recv() fail the refcount won't be decremented. And it's easy to see from ftrace log, that rds_inc_addref() don't have rds_inc_put() pair in rds_recvmsg() after rds_cmsg_recv() 1) | rds_recvmsg() { 1) 3.721 us | rds_inc_addref(); 1) 3.853 us | rds_message_inc_copy_to_user(); 1) + 10.395 us | rds_cmsg_recv(); 1) + 34.260 us | }

Package Linux Kernel
Published 2024-05-21
Last modified 2024-12-30
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-401

CVE-2021-47249 is a Memory Leak vulnerability

What is Memory Leak?

The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE

Affected versions

Linux kernel versions 2.6.30 and later are affected. Fixed in 4.4.274, 4.9.274, 4.14.238, 4.19.196, 5.4.128, 5.10.46, 5.12.13, 5.13 and their respective stable series.

Affected from
≥ 2.6.30
Fixed in
✓ 4.4.274 4.4.x ✓ 4.9.274 4.9.x ✓ 4.14.238 4.14.x ✓ 4.19.196 4.19.x ✓ 5.4.128 5.4.x ✓ 5.10.46 5.10.x ✓ 5.12.13 5.12.x ✓ 5.13

Frequently asked questions

  • What is CVE-2021-47249?

    CVE-2021-47249 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 2.6.30 onward and has been patched in 4.4.274, 4.9.274, 4.14.238 and others. CVE-2021-47249 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2021-47249?

    CVE-2021-47249 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2021-47249?

    Yes. CVE-2021-47249 has been patched. Fixed versions include 4.4.274, 4.9.274, 4.14.238 and others. If you are running Linux kernel 2.6.30 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2021-47249 actively exploited?

    No. CVE-2021-47249 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.