What’s Vulnerable › Vulnerabilities

CVE-2025-40200: Squashfs: reject negative file sizes in squashfs_read_inode()

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-11-12 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: Squashfs: reject negative file sizes in squashfs_read_inode() Syskaller reports a "WARNING in ovl_copy_up_file" in overlayfs. This warning is ultimately caused because the underlying Squashfs file system returns a file with a negative file size. This commit checks for a negative file size and returns EINVAL. [phillip@squashfs.org.uk: only need to check 64 bit quantity]

Affected products

• Linux kernel: 2.6.29 — fixed in 6.18

How to fix

Upgrade to a fixed version: Linux kernel 6.18. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/2871c74caa3f4f05b429e6bfefebac62dbf1b408
• https://git.kernel.org/stable/c/54170057a5fadd24a37b70de41e61d39284d9bd7
• https://git.kernel.org/stable/c/8118f66124895829443d09c207e654adcb2f9321
• https://git.kernel.org/stable/c/875fb3f87ae0225b881319ba016a1a8c4ffd5812
• https://git.kernel.org/stable/c/8c7aad76751816207fee556d44aa88a710824810
• https://git.kernel.org/stable/c/9f1c14c1de1bdde395f6cc893efa4f80a2ae3b2b
• https://git.kernel.org/stable/c/f271155ff31aca8ef82c61c8df23ca97e9a77dd4
• https://git.kernel.org/stable/c/fbfc745db628de31f5c089147deeb87e95b89e66

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