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Vulnerability · Published Mar 15, 2024 · Assigned by Linux

CVE-2021-47114ocfs2: fix data corruption by fallocate

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.2%top 86.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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/20210525093034.GB4112@quack2.suse.cz/T/

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.10.46-1DEBIAN-CVE-2021-47114
Debian:13linux5.10.46-1DEBIAN-CVE-2021-47114
Debian:14linux5.10.46-1DEBIAN-CVE-2021-47114
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2021-47114
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2021-47114
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2021-47114

Affected products (as reported)

VendorProductVersions
Linux Linux 385820a38d5e7c70b20af4d68767b1920b1e4133 – before 624fa7baa3788dc9e57840ba5b94bc22b03cda57385820a38d5e7c70b20af4d68767b1920b1e4133 – before 33e03adafb29eedae1bae9cdb50c1385279fcf65385820a38d5e7c70b20af4d68767b1920b1e4133 – before a1700479524bb9cb5e8ae720236a6fabd003acae385820a38d5e7c70b20af4d68767b1920b1e4133 – before cec4e857ffaa8c447f51cd8ab4e72350077b6770385820a38d5e7c70b20af4d68767b1920b1e4133 – before cc2edb99ea606a45182b5ea38cc8f4e583aa0774385820a38d5e7c70b20af4d68767b1920b1e4133 – before c8d5faee46242c3f33b8a71a4d7d52214785bfcc385820a38d5e7c70b20af4d68767b1920b1e4133 – before 0a31dd6fd2f4e7db538fb6eb1f06973d81f8dd3b385820a38d5e7c70b20af4d68767b1920b1e4133 – before 6bba4471f0cc1296fe3c2089b9e52442d3074b2e
Linux Linux 2.6.23

References