CVE-2024-26704

HIGH
Published Apr 3, 2024 Modified Jan 14, 2025 CWE-415

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: fix double-free of blocks due to wrong extents moved_len In ext4_move_extents(), moved_len is only updated when all moves are successfully executed, and only discards orig_inode and donor_inode preallocations when moved_len is not zero. When the loop fails to exit after successfully moving some extents, moved_len is not updated and remains at 0, so it does not discard the preallocations. If the moved extents overlap with the preallocated extents, the overlapped extents are freed twice in ext4_mb_release_inode_pa() and ext4_process_freed_data() (as described in commit 94d7c16cbbbd ("ext4: Fix double-free of blocks with EXT4_IOC_MOVE_EXT")), and bb_free is incremented twice. Hence when trim is executed, a zero-division bug is triggered in mb_update_avg_fragment_size() because bb_free is not zero and bb_fragments is zero. Therefore, update move_len after each extent move to avoid the issue.

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CVSS v3.1 Score

7.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-415 CWE-415

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
debian debian_linux

References

Advisories & Patches

https://git.kernel.org/stable/c/185eab30486ba3e7bf8b9c2e049c79a06ffd2bc1 https://git.kernel.org/stable/c/2883940b19c38d5884c8626483811acf4d7e148f https://git.kernel.org/stable/c/55583e899a5357308274601364741a83e78d6ac4 https://git.kernel.org/stable/c/559ddacb90da1d8786dd8ec4fd76bbfa404eaef6 https://git.kernel.org/stable/c/afba9d11320dad5ce222ac8964caf64b7b4bedb1 https://git.kernel.org/stable/c/afbcad9ae7d6d11608399188f03a837451b6b3a1 https://git.kernel.org/stable/c/b4fbb89d722cbb16beaaea234b7230faaaf68c71 https://git.kernel.org/stable/c/d033a555d9a1cf53dbf3301af7199cc4a4c8f537 https://git.kernel.org/stable/c/185eab30486ba3e7bf8b9c2e049c79a06ffd2bc1 https://git.kernel.org/stable/c/2883940b19c38d5884c8626483811acf4d7e148f https://git.kernel.org/stable/c/55583e899a5357308274601364741a83e78d6ac4 https://git.kernel.org/stable/c/559ddacb90da1d8786dd8ec4fd76bbfa404eaef6 https://git.kernel.org/stable/c/afba9d11320dad5ce222ac8964caf64b7b4bedb1 https://git.kernel.org/stable/c/afbcad9ae7d6d11608399188f03a837451b6b3a1 https://git.kernel.org/stable/c/b4fbb89d722cbb16beaaea234b7230faaaf68c71 https://git.kernel.org/stable/c/d033a555d9a1cf53dbf3301af7199cc4a4c8f537

Frequently Asked Questions

What is CVE-2024-26704? +
In the Linux kernel, the following vulnerability has been resolved: ext4: fix double-free of blocks due to wrong extents moved_len In ext4_move_extents(), moved_len is only updated when all moves are successfully executed, and only discards orig_inode and donor_inode preallocations when moved_len is not zero. When the loop fails to exit after successfully moving some extents, moved_len is not updated and remains at 0, so it does not discard the preallocations. If the moved extents overlap with the preallocated extents, the overlapped extents are freed twice in ext4_mb_release_inode_pa() and ext4_process_freed_data() (as described in commit 94d7c16cbbbd ("ext4: Fix double-free of blocks with EXT4_IOC_MOVE_EXT")), and bb_free is incremented twice. Hence when trim is executed, a zero-division bug is triggered in mb_update_avg_fragment_size() because bb_free is not zero and bb_fragments is zero. Therefore, update move_len after each extent move to avoid the issue. It has a CVSS v3.1 base score of 7.8 (HIGH).
How severe is CVE-2024-26704? +
CVE-2024-26704 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
What products are affected by CVE-2024-26704? +
CVE-2024-26704 affects products from debian, linux, specifically: debian_linux, linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2024-26704? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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