Medium 5.5Published Apr 24, 2026

CVE-2026-31577nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map

Updated under an hour ago (Oct 28, 2026, 5:10 AM ET)

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Exploited in the last 30 days

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.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Jun 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from d626fcdabea2258be395a775bdbe09270e9bf73d before 6637bbcfb59df5b732a79e5ab1a74886a0b93d59; from d05cc5395e36711edad8bdef6945f138d8a7097b before 837c7a59fb58f81b0db33848357f6a5d0d1250ad; from e897be17a441fa637cd166fc3de1445131e57692 before 7902b1df1520a0880bcda7a3704cfacd17905a83; from e897be17a441fa637cd166fc3de1445131e57692 before 7318e3549518ce8f14776a489d86488d80d7e2c8; from e897be17a441fa637cd166fc3de1445131e57692 before 449ec5fc99f45974525ba9eea16b6670c45cd363; from e897be17a441fa637cd166fc3de1445131e57692 before c36e206f302f1ddefed92d09ecbba070e1ae079e; from e897be17a441fa637cd166fc3de1445131e57692 before 41de342278ae025c99cc8d33648773f05e306cf1; from e897be17a441fa637cd166fc3de1445131e57692 before 97fb7afec404912d967a7d4715f37742666b3084; and 11 more ranges	CNA record
linux linux_kernel linux:linux_kernel	before 6.6.136; from 6.7 before 6.12.83; from 6.13 before 6.18.24; from 6.19 before 6.19.14; from 7.0 before 7.0.1	NVD

References

References

https://git.kernel.org/stable/c/6637bbcfb59df5b732a79e5ab1a74886a0b93d59
https://git.kernel.org/stable/c/837c7a59fb58f81b0db33848357f6a5d0d1250ad
https://git.kernel.org/stable/c/7902b1df1520a0880bcda7a3704cfacd17905a83
https://git.kernel.org/stable/c/7318e3549518ce8f14776a489d86488d80d7e2c8	patch
https://git.kernel.org/stable/c/449ec5fc99f45974525ba9eea16b6670c45cd363	patch
https://git.kernel.org/stable/c/c36e206f302f1ddefed92d09ecbba070e1ae079e	patch
https://git.kernel.org/stable/c/41de342278ae025c99cc8d33648773f05e306cf1	patch
https://git.kernel.org/stable/c/97fb7afec404912d967a7d4715f37742666b3084	patch
https://git.kernel.org/stable/c/4a4e0328edd9e9755843787d28f16dd4165f8b48	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.