CVE-2021-47482

Medium

In the Linux kernel, the following vulnerability has been resolved: net: batman-adv: fix error handling Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was in wrong error handling in batadv_mesh_init(). Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case of any batadv_*_init() calls failure. This approach may work well, when there is some kind of indicator, which can tell which parts of batadv are initialized; but there isn't any. All written above lead to cleaning up uninitialized fields. Even if we hide ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1] To fix these bugs we can unwind batadv_*_init() calls one by one. It is good approach for 2 reasons: 1) It fixes bugs on error handling path 2) It improves the performance, since we won't call unneeded batadv_*_free() functions. So, this patch makes all batadv_*_init() clean up all allocated memory before returning with an error to no call correspoing batadv_*_free() and open-codes batadv_mesh_free() with proper order to avoid touching uninitialized fields.

Package Linux Kernel
Published 2024-05-22
Last modified 2025-04-02
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.3

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

Weakness type

CWE-544

CVE-2021-47482 is classified as CWE-544

See CWE-544 on MITRE CWE for full details on this weakness type.

Affected versions

Linux kernel versions 2.6.38 and later are affected. Fixed in 4.4.293, 4.9.289, 4.14.254, 4.19.215, 5.4.157, 5.10.77, 5.14.16, 5.15 and their respective stable series.

Affected from
≥ 2.6.38
Fixed in
✓ 4.4.293 4.4.x ✓ 4.9.289 4.9.x ✓ 4.14.254 4.14.x ✓ 4.19.215 4.19.x ✓ 5.4.157 5.4.x ✓ 5.10.77 5.10.x ✓ 5.14.16 5.14.x ✓ 5.15

References

8 total
Showing 5 of 8 references View all on NVD

Frequently asked questions

  • What is CVE-2021-47482?

    CVE-2021-47482 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.3 out of 10 . It affects Linux kernel versions from 2.6.38 onward and has been patched in 4.4.293, 4.9.289, 4.14.254 and others. CVE-2021-47482 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2021-47482?

    CVE-2021-47482 has a CVSS score of 5.3 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2021-47482?

    Yes. CVE-2021-47482 has been patched. Fixed versions include 4.4.293, 4.9.289, 4.14.254 and others. If you are running Linux kernel 2.6.38 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2021-47482 actively exploited?

    No. CVE-2021-47482 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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