CVE-2021-47280

High

In the Linux kernel, the following vulnerability has been resolved: drm: Fix use-after-free read in drm_getunique() There is a time-of-check-to-time-of-use error in drm_getunique() due to retrieving file_priv->master prior to locking the device's master mutex. An example can be seen in the crash report of the use-after-free error found by Syzbot: https://syzkaller.appspot.com/bug?id=148d2f1dfac64af52ffd27b661981a540724f803 In the report, the master pointer was used after being freed. This is because another process had acquired the device's master mutex in drm_setmaster_ioctl(), then overwrote fpriv->master in drm_new_set_master(). The old value of fpriv->master was subsequently freed before the mutex was unlocked. To fix this, we lock the device's master mutex before retrieving the pointer from from fpriv->master. This patch passes the Syzbot reproducer test.

Package Linux Kernel
Published 2024-05-21
Last modified 2024-12-24
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.0

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

Weakness type

CWE-367

CVE-2021-47280 is classified as CWE-367

See CWE-367 on MITRE CWE for full details on this weakness type.

Affected versions

Linux kernel versions 4.11 and later are affected. Fixed in 4.14.237, 4.19.195, 5.4.126, 5.10.44, 5.12.11, 5.13 and their respective stable series.

Affected from
≥ 4.11
Fixed in
✓ 4.14.237 4.14.x ✓ 4.19.195 4.19.x ✓ 5.4.126 5.4.x ✓ 5.10.44 5.10.x ✓ 5.12.11 5.12.x ✓ 5.13

References

6 total
Showing 5 of 6 references View all on NVD

Frequently asked questions

  • What is CVE-2021-47280?

    CVE-2021-47280 is a High severity Linux kernel vulnerability with a CVSS score of 7.0 out of 10 . It affects Linux kernel versions from 4.11 onward and has been patched in 4.14.237, 4.19.195, 5.4.126 and others. CVE-2021-47280 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2021-47280?

    CVE-2021-47280 has a CVSS score of 7.0 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2021-47280?

    Yes. CVE-2021-47280 has been patched. Fixed versions include 4.14.237, 4.19.195, 5.4.126 and others. If you are running Linux kernel 4.11 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2021-47280 actively exploited?

    No. CVE-2021-47280 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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