CVE-2026-31577
nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map
Description
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.
INFO
Published Date :
April 24, 2026, 3:16 p.m.
Last Modified :
June 1, 2026, 5:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Apply the kernel patch for nilfs2.
- Update the Linux kernel.
- Reboot the system after patching.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-31577.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-31577 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-31577
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-31577 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-31577 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 01, 2026
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/6637bbcfb59df5b732a79e5ab1a74886a0b93d59 Added Reference https://git.kernel.org/stable/c/7902b1df1520a0880bcda7a3704cfacd17905a83 Added Reference https://git.kernel.org/stable/c/837c7a59fb58f81b0db33848357f6a5d0d1250ad -
Initial Analysis by [email protected]
Apr. 27, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.24 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 6.19.14 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 7.0 up to (excluding) 7.0.1 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (excluding) 6.6.136 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.83 Added Reference Type kernel.org: https://git.kernel.org/stable/c/41de342278ae025c99cc8d33648773f05e306cf1 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/449ec5fc99f45974525ba9eea16b6670c45cd363 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/4a4e0328edd9e9755843787d28f16dd4165f8b48 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/7318e3549518ce8f14776a489d86488d80d7e2c8 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/97fb7afec404912d967a7d4715f37742666b3084 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c36e206f302f1ddefed92d09ecbba070e1ae079e Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 27, 2026
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/7318e3549518ce8f14776a489d86488d80d7e2c8 -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 27, 2026
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/4a4e0328edd9e9755843787d28f16dd4165f8b48 -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 24, 2026
Action Type Old Value New Value Added Description 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. Added Reference https://git.kernel.org/stable/c/41de342278ae025c99cc8d33648773f05e306cf1 Added Reference https://git.kernel.org/stable/c/449ec5fc99f45974525ba9eea16b6670c45cd363 Added Reference https://git.kernel.org/stable/c/97fb7afec404912d967a7d4715f37742666b3084 Added Reference https://git.kernel.org/stable/c/c36e206f302f1ddefed92d09ecbba070e1ae079e