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CVE-2025-40049

UnknownEPSS 0.21%

Last modified

CVE-2025-40049 is a vulnerability of currently unknown severity. In the Linux kernel, the following vulnerability has been resolved: Squashfs: fix uninit-value in squashfs_get_parent Syzkaller reports a "KMSAN: uninit-value in squashfs_get_parent" bug. This is caused by open_by_handle_at() being called with a file handle containing an invalid parent inode number. In particular the inode number is that of a symbolic link, rather than a directory. Squashfs_get_parent() gets called with that symbolic link inode, and accesses the parent member field. unsigned int parent_ino = squashfs_i(inode)->parent; Because non-directory inodes in Squashfs do not have a parent value, this is uninitialised, and this causes an uninitialised value access. The fix is to initialise parent with the invalid inode 0, which will cause an EINVAL error to be returned. Regular inodes used to share the parent field with the block_list_start field. EPSS estimates a 0.21% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: Squashfs: fix uninit-value in squashfs_get_parent Syzkaller reports a "KMSAN: uninit-value in squashfs_get_parent" bug. This is caused by open_by_handle_at() being called with a file handle containing an invalid parent inode number. In particular the inode number is that of a symbolic link, rather than a directory. Squashfs_get_parent() gets called with that symbolic link inode, and accesses the parent member field. unsigned int parent_ino = squashfs_i(inode)->parent; Because non-directory inodes in Squashfs do not have a parent value, this is uninitialised, and this causes an uninitialised value access. The fix is to initialise parent with the invalid inode 0, which will cause an EINVAL error to be returned. Regular inodes used to share the parent field with the block_list_start field. This is removed in this commit to enable the parent field to contain the invalid inode number 0.

Metrics

EPSS Probability
0.21%

10.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 122601408d20c77704268f1dea9f9ce4abf997c2, < f81a5bc9e924ee1950e0dd82bd10749048390f6e; >= 122601408d20c77704268f1dea9f9ce4abf997c2, < 382a47fae449e554ef1e8c198667fd2f3270b945; >= 122601408d20c77704268f1dea9f9ce4abf997c2, < 61d38b5ce2782bff3cacaacbb8164087a73ed1a5; >= 122601408d20c77704268f1dea9f9ce4abf997c2, < 81a2bca52d43fc9d9abf07408b91255131c5dc53; >= 122601408d20c77704268f1dea9f9ce4abf997c2, < c28b0ca029edf5d0558abcd76cb8c732706cd339; >= 122601408d20c77704268f1dea9f9ce4abf997c2, < 1b3ccd0019132880c94bb00ca7088c1749308f82; >= 122601408d20c77704268f1dea9f9ce4abf997c2, < 91b99db7a92e57ff48a96a1b10fddfd2547e7f53; >= 122601408d20c77704268f1dea9f9ce4abf997c2, < 74058c0a9fc8b2b4d5f4a0ef7ee2cfa66a9e49cf
LinuxLinux2.6.29

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2025-40049?
In the Linux kernel, the following vulnerability has been resolved: Squashfs: fix uninit-value in squashfs_get_parent Syzkaller reports a "KMSAN: uninit-value in squashfs_get_parent" bug. This is caused by open_by_handle_at() being called with a file handle containing an invalid parent inode number. In particular the inode number is that of a symbolic link, rather than a directory. Squashfs_get_parent() gets called with that symbolic link inode, and accesses the parent member field. unsigned int parent_ino = squashfs_i(inode)->parent; Because non-directory inodes in Squashfs do not have a parent value, this is uninitialised, and this causes an uninitialised value access. The fix is to initialise parent with the invalid inode 0, which will cause an EINVAL error to be returned. Regular inodes used to share the parent field with the block_list_start field. This is removed in this commit to enable the parent field to contain the invalid inode number 0.
How severe is CVE-2025-40049?
Severity scoring for CVE-2025-40049 is pending analysis. The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.
How do I fix CVE-2025-40049?
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