CVE-2024-46744: In the Linux kernel, the following vulnerability has been resolved: Squashfs: sanity check symbolic link size Syzkiller reports a "KMSAN: uninit-val...

Description

In the Linux kernel, the following vulnerability has been resolved: Squashfs: sanity check symbolic link size Syzkiller reports a "KMSAN: uninit-value in pick_link" bug. This is caused by an uninitialised page, which is ultimately caused by a corrupted symbolic link size read from disk. The reason why the corrupted symlink size causes an uninitialised page is due to the following sequence of events: 1. squashfs_read_inode() is called to read the symbolic link from disk. This assigns the corrupted value 3875536935 to inode->i_size. 2. Later squashfs_symlink_read_folio() is called, which assigns this corrupted value to the length variable, which being a signed int, overflows producing a negative number. 3. The following loop that fills in the page contents checks that the copied bytes is less than length, which being negative means the loop is skipped, producing an uninitialised page. This patch adds a sanity check which checks that the symbolic link size is not larger than expected. -- V2: fix spelling mistake.

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

0.30%

21.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-59

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	< 4.19.322	—
Linux	Linux Kernel	>= 4.20, < 5.4.284	—
Linux	Linux Kernel	>= 5.5, < 5.10.226	—
Linux	Linux Kernel	>= 5.11, < 5.15.167	—
Linux	Linux Kernel	>= 5.16, < 6.1.110	—
Linux	Linux Kernel	>= 6.2, < 6.6.51	—
Linux	Linux Kernel	>= 6.7, < 6.10.10	—
Linux	Linux Kernel	6.11	Rc1

References

Timeline

Published: Sep 18, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-46744?

In the Linux kernel, the following vulnerability has been resolved: Squashfs: sanity check symbolic link size Syzkiller reports a "KMSAN: uninit-value in pick_link" bug. This is caused by an uninitialised page, which is ultimately caused by a corrupted symbolic link size read from disk. The reason why the corrupted symlink size causes an uninitialised page is due to the following sequence of events: 1. squashfs_read_inode() is called to read the symbolic link from disk. This assigns the corrupted value 3875536935 to inode->i_size. 2. Later squashfs_symlink_read_folio() is called, which assigns this corrupted value to the length variable, which being a signed int, overflows producing a negative number. 3. The following loop that fills in the page contents checks that the copied bytes is less than length, which being negative means the loop is skipped, producing an uninitialised page. This patch adds a sanity check which checks that the symbolic link size is not larger than expected. -- V2: fix spelling mistake.

How severe is CVE-2024-46744?

CVE-2024-46744 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.

How do I fix CVE-2024-46744?

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.