CVE-2024-26981: nilfs2: fix OOB in nilfs_set_de_type

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-01 · updated 2026-06-17
Weakness: CWE-129

Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix OOB in nilfs_set_de_type The size of the nilfs_type_by_mode array in the fs/nilfs2/dir.c file is defined as "S_IFMT >> S_SHIFT", but the nilfs_set_de_type() function, which uses this array, specifies the index to read from the array in the same way as "(mode & S_IFMT) >> S_SHIFT". static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode *inode) { umode_t mode = inode->i_mode; de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; // oob } However, when the index is determined this way, an out-of-bounds (OOB) error occurs by referring to an index that is 1 larger than the array size when the condition "mode & S_IFMT == S_IFMT" is satisfied. Therefore, a patch to resize the nilfs_type_by_mode array should be applied to prevent OOB errors.

Affected products

Debian Linux: 10.0
Linux kernel: from 2.6.30 before 4.19.313; from 4.20 before 5.4.275; from 5.5 before 5.10.216; from 5.11 before 5.15.157; from 5.16 before 6.1.88; from 6.2 before 6.6.29 — fixed in 4.19.313, 5.10.216, 5.15.157, 5.4.275, 6.1.88, 6.6.29

How to fix

Upgrade to a fixed version: Linux kernel 4.19.313, 5.10.216, 5.15.157, 5.4.275. Check the vendor advisory for mitigations.

References

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