What is CVE-2021-47493?

CVE-2021-47493 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10, classified as a Race Condition flaw (CWE-362), affecting Linux kernel versions from 2.6.16 onward and patched in 5.10.77, 5.14.16 and 5.15. CVE-2021-47493 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47493?

CVE-2021-47493 has a CVSS score of 4.7 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2021-47493?

Yes, CVE-2021-47493 has been patched. Fixed versions include 5.10.77, 5.14.16 and 5.15. If you are running Linux kernel 2.6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2021-47493 actively exploited?

CVE-2021-47493 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Race Condition (CWE-362)?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/362.html

CVE-2021-47493

Medium

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix race between searching chunks and release journal_head from buffer_head Encountered a race between ocfs2_test_bg_bit_allocatable() and jbd2_journal_put_journal_head() resulting in the below vmcore. PID: 106879 TASK: ffff880244ba9c00 CPU: 2 COMMAND: "loop3" Call trace: panic oops_end no_context __bad_area_nosemaphore bad_area_nosemaphore __do_page_fault do_page_fault page_fault [exception RIP: ocfs2_block_group_find_clear_bits+316] ocfs2_block_group_find_clear_bits [ocfs2] ocfs2_cluster_group_search [ocfs2] ocfs2_search_chain [ocfs2] ocfs2_claim_suballoc_bits [ocfs2] __ocfs2_claim_clusters [ocfs2] ocfs2_claim_clusters [ocfs2] ocfs2_local_alloc_slide_window [ocfs2] ocfs2_reserve_local_alloc_bits [ocfs2] ocfs2_reserve_clusters_with_limit [ocfs2] ocfs2_reserve_clusters [ocfs2] ocfs2_lock_refcount_allocators [ocfs2] ocfs2_make_clusters_writable [ocfs2] ocfs2_replace_cow [ocfs2] ocfs2_refcount_cow [ocfs2] ocfs2_file_write_iter [ocfs2] lo_rw_aio loop_queue_work kthread_worker_fn kthread ret_from_fork When ocfs2_test_bg_bit_allocatable() called bh2jh(bg_bh), the bg_bh->b_private NULL as jbd2_journal_put_journal_head() raced and released the jounal head from the buffer head. Needed to take bit lock for the bit 'BH_JournalHead' to fix this race.

Package Linux Kernel

Published 2024-05-22

Last modified 2025-09-24

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

4.7

out of 10

Medium

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-362

CVE-2021-47493 is a Race Condition vulnerability

What is Race Condition?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. Learn more on MITRE CWE

Affected versions

Linux kernel versions 2.6.16 and later are affected. Fixed in 5.10.77, 5.14.16, 5.15 and their respective stable series.

Affected from

≥ 2.6.16

Fixed in

✓ 5.10.77 5.10.x ✓ 5.14.16 5.14.x ✓ 5.15

References

3 total

Kernel Git
https://git.kernel.org/stable/c/2e382600e8856ea654677b5134ee66e03ea72bc2

Patch
Kernel Git
https://git.kernel.org/stable/c/5043fbd294f5909a080ade0f04b70a4da9e122b7

Patch
Kernel Git
https://git.kernel.org/stable/c/6f1b228529ae49b0f85ab89bcdb6c365df401558

Patch

Details

CVE ID CVE-2021-47493

Severity Medium

CVSS score 4.7 / 10

CVSS version 3.1

Published 2024-05-22

Modified 2025-09-24

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2021-47493?

CVE-2021-47493 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10 , classified as a Race Condition flaw (CWE-362) . It affects Linux kernel versions from 2.6.16 onward and has been patched in 5.10.77, 5.14.16 and 5.15. CVE-2021-47493 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47493?

CVE-2021-47493 has a CVSS score of 4.7 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2021-47493?

Yes. CVE-2021-47493 has been patched. Fixed versions include 5.10.77, 5.14.16 and 5.15. If you are running Linux kernel 2.6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2021-47493 actively exploited?

No. CVE-2021-47493 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.