CVE-2021-47433 btrfs: fix abort logic in btrfs_replace_file_extents

What is CVE-2021-47433?

CVE-2021-47433 is a high-severity vulnerability in Linux kernel, published on 22 May 2024. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

btrfs: fix abort logic in btrfs_replace_file_extents

Error injection testing uncovered a case where we'd end up with a corrupt file system with a missing extent in the middle of a file. This occurs because the if statement to decide if we should abort is wrong.

The only way we would abort in this case is if we got a ret != -EOPNOTSUPP and we called from the file clone code. However the prealloc code uses this path too. Instead we need to abort if there is an error, and the only error we _don't_ abort on is -EOPNOTSUPP and only if we came from the clone file code.

Which versions are affected by CVE-2021-47433?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47433?

Apply the vendor's patch.

Is CVE-2021-47433 being exploited?

There is no known exploitation of CVE-2021-47433 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-47433, GHSA-6x3x-fg57-3vcm, UBUNTU-CVE-2021-47433.