CVE-2021-47114
QEMU OCFS2 Fallocate Data Corruption Vulnerability
Description
In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix data corruption by fallocate When fallocate punches holes out of inode size, if original isize is in the middle of last cluster, then the part from isize to the end of the cluster will be zeroed with buffer write, at that time isize is not yet updated to match the new size, if writeback is kicked in, it will invoke ocfs2_writepage()->block_write_full_page() where the pages out of inode size will be dropped. That will cause file corruption. Fix this by zero out eof blocks when extending the inode size. Running the following command with qemu-image 4.2.1 can get a corrupted coverted image file easily. qemu-img convert -p -t none -T none -f qcow2 $qcow_image \ -O qcow2 -o compat=1.1 $qcow_image.conv The usage of fallocate in qemu is like this, it first punches holes out of inode size, then extend the inode size. fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0 fallocate(11, 0, 2276196352, 65536) = 0 v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html v2: https://lore.kernel.org/linux-fsdevel/[email protected]/T/
INFO
Published Date :
March 15, 2024, 9:15 p.m.
Last Modified :
April 4, 2025, 2:39 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update the Linux kernel to a patched version.
- Reboot the system after the update.
Public PoC/Exploit Available at Github
CVE-2021-47114 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47114.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47114 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47114
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Ini adalah repository kumpulan CVE v.5
allcve cve cvelist newcve
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-47114 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47114 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Apr. 04, 2025
Action Type Old Value New Value Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.12.10 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.43 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (excluding) 4.4.272 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.5 up to (excluding) 4.9.272 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.10 up to (excluding) 4.14.236 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.15 up to (excluding) 4.19.194 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.20 up to (excluding) 5.4.125 Added Reference Type CVE: https://git.kernel.org/stable/c/0a31dd6fd2f4e7db538fb6eb1f06973d81f8dd3b Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/0a31dd6fd2f4e7db538fb6eb1f06973d81f8dd3b Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/33e03adafb29eedae1bae9cdb50c1385279fcf65 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/33e03adafb29eedae1bae9cdb50c1385279fcf65 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/624fa7baa3788dc9e57840ba5b94bc22b03cda57 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/624fa7baa3788dc9e57840ba5b94bc22b03cda57 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/6bba4471f0cc1296fe3c2089b9e52442d3074b2e Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/6bba4471f0cc1296fe3c2089b9e52442d3074b2e Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/a1700479524bb9cb5e8ae720236a6fabd003acae Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a1700479524bb9cb5e8ae720236a6fabd003acae Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/c8d5faee46242c3f33b8a71a4d7d52214785bfcc Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c8d5faee46242c3f33b8a71a4d7d52214785bfcc Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/cc2edb99ea606a45182b5ea38cc8f4e583aa0774 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/cc2edb99ea606a45182b5ea38cc8f4e583aa0774 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/cec4e857ffaa8c447f51cd8ab4e72350077b6770 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/cec4e857ffaa8c447f51cd8ab4e72350077b6770 Types: Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/0a31dd6fd2f4e7db538fb6eb1f06973d81f8dd3b Added Reference https://git.kernel.org/stable/c/33e03adafb29eedae1bae9cdb50c1385279fcf65 Added Reference https://git.kernel.org/stable/c/624fa7baa3788dc9e57840ba5b94bc22b03cda57 Added Reference https://git.kernel.org/stable/c/6bba4471f0cc1296fe3c2089b9e52442d3074b2e Added Reference https://git.kernel.org/stable/c/a1700479524bb9cb5e8ae720236a6fabd003acae Added Reference https://git.kernel.org/stable/c/c8d5faee46242c3f33b8a71a4d7d52214785bfcc Added Reference https://git.kernel.org/stable/c/cc2edb99ea606a45182b5ea38cc8f4e583aa0774 Added Reference https://git.kernel.org/stable/c/cec4e857ffaa8c447f51cd8ab4e72350077b6770 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Nov. 05, 2024
Action Type Old Value New Value Added CVSS V3.1 CISA-ADP AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 14, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Mar. 15, 2024
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix data corruption by fallocate When fallocate punches holes out of inode size, if original isize is in the middle of last cluster, then the part from isize to the end of the cluster will be zeroed with buffer write, at that time isize is not yet updated to match the new size, if writeback is kicked in, it will invoke ocfs2_writepage()->block_write_full_page() where the pages out of inode size will be dropped. That will cause file corruption. Fix this by zero out eof blocks when extending the inode size. Running the following command with qemu-image 4.2.1 can get a corrupted coverted image file easily. qemu-img convert -p -t none -T none -f qcow2 $qcow_image \ -O qcow2 -o compat=1.1 $qcow_image.conv The usage of fallocate in qemu is like this, it first punches holes out of inode size, then extend the inode size. fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2276196352, 65536) = 0 fallocate(11, 0, 2276196352, 65536) = 0 v1: https://www.spinics.net/lists/linux-fsdevel/msg193999.html v2: https://lore.kernel.org/linux-fsdevel/[email protected]/T/ Added Reference kernel.org https://git.kernel.org/stable/c/624fa7baa3788dc9e57840ba5b94bc22b03cda57 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/33e03adafb29eedae1bae9cdb50c1385279fcf65 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/a1700479524bb9cb5e8ae720236a6fabd003acae [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/cec4e857ffaa8c447f51cd8ab4e72350077b6770 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/cc2edb99ea606a45182b5ea38cc8f4e583aa0774 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/c8d5faee46242c3f33b8a71a4d7d52214785bfcc [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/0a31dd6fd2f4e7db538fb6eb1f06973d81f8dd3b [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/6bba4471f0cc1296fe3c2089b9e52442d3074b2e [No types assigned]