CVE-2026-31577 (GCVE-0-2026-31577)

Vulnerability from cvelistv5 – Published: 2026-04-24 14:42 – Updated: 2026-04-24 14:42
VLAI?
Title
nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map
Summary
In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map The DAT inode's btree node cache (i_assoc_inode) is initialized lazily during btree operations. However, nilfs_mdt_save_to_shadow_map() assumes i_assoc_inode is already initialized when copying dirty pages to the shadow map during GC. If NILFS_IOCTL_CLEAN_SEGMENTS is called immediately after mount before any btree operation has occurred on the DAT inode, i_assoc_inode is NULL leading to a general protection fault. Fix this by calling nilfs_attach_btree_node_cache() on the DAT inode in nilfs_dat_read() at mount time, ensuring i_assoc_inode is always initialized before any GC operation can use it.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 449ec5fc99f45974525ba9eea16b6670c45cd363 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < c36e206f302f1ddefed92d09ecbba070e1ae079e (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 41de342278ae025c99cc8d33648773f05e306cf1 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 97fb7afec404912d967a7d4715f37742666b3084 (git)
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    Linux Linux Unaffected: 6.12.83 , ≤ 6.12.* (semver)
Unaffected: 6.18.24 , ≤ 6.18.* (semver)
Unaffected: 6.19.14 , ≤ 6.19.* (semver)
Unaffected: 7.0.1 , ≤ 7.0.* (semver)
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map\n\nThe DAT inode\u0027s btree node cache (i_assoc_inode) is initialized lazily\nduring btree operations. However, nilfs_mdt_save_to_shadow_map()\nassumes i_assoc_inode is already initialized when copying dirty pages\nto the shadow map during GC.\n\nIf NILFS_IOCTL_CLEAN_SEGMENTS is called immediately after mount before\nany btree operation has occurred on the DAT inode, i_assoc_inode is\nNULL leading to a general protection fault.\n\nFix this by calling nilfs_attach_btree_node_cache() on the DAT inode\nin nilfs_dat_read() at mount time, ensuring i_assoc_inode is always\ninitialized before any GC operation can use it."
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    "datePublished": "2026-04-24T14:42:08.879Z",
    "dateReserved": "2026-03-09T15:48:24.119Z",
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