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CVE-2024-26704

HIGHCVSS 7.8/10EPSS 0.27%

Last modified

CVE-2024-26704 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. 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. EPSS estimates a 0.27% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
7.8/10

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

EPSS Probability
0.27%

17.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 3.18, < 4.19.307—
LinuxLinux Kernel>= 4.20, < 5.4.269—
LinuxLinux Kernel>= 5.5, < 5.10.210—
LinuxLinux Kernel>= 5.11, < 5.15.149—
LinuxLinux Kernel>= 5.16, < 6.1.79—
LinuxLinux Kernel>= 6.2, < 6.6.18—
LinuxLinux Kernel>= 6.7, < 6.7.6—
LinuxLinux Kernel6.8Rc1
DebianDebian Linux10.0—

References

Timeline

Published
Last Modified
Status
Analyzed

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.
How severe is CVE-2024-26704?
CVE-2024-26704 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.27% probability of exploitation in the next 30 days.
How do I fix CVE-2024-26704?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST