CVE-2026-31598: linux Improper Locking
Vulnerability summary
CVE-2026-31598 is a high (CVSS 7.5) Improper Locking vulnerability in linux. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.7% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 51 · Related 52Timeline
- 24-04-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix possible deadlock between unlink and dio_end_io_write ocfs2_unlink takes orphan dir inode_lock first and then ip_alloc_sem, while in ocfs2_dio_end_io_write, it acquires these locks in reverse order. This creates an ABBA lock ordering violation on lock classes ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE] and ocfs2_file_ip_alloc_sem_key. Lock Chain #0 (orphan dir inode_lock -> ip_alloc_sem): ocfs2_unlink ocfs2_prepare_orphan_dir ocfs2_lookup_lock_orphan_dir inode_lock(orphan_dir_inode) <- lock A __ocfs2_prepare_orphan_dir ocfs2_prepare_dir_for_insert ocfs2_extend_dir ocfs2_expand_inline_dir down_write(&oi->ip_alloc_sem) <- Lock B Lock Chain #1 (ip_alloc_sem -> orphan dir inode_lock): ocfs2_dio_end_io_write down_write(&oi->ip_alloc_sem) <- Lock B ocfs2_del_inode_from_orphan() inode_lock(orphan_dir_inode) <- Lock A Deadlock Scenario: CPU0 (unlink) CPU1 (dio_end_io_write) ------ ------ inode_lock(orphan_dir_inode) down_write(ip_alloc_sem) down_write(ip_alloc_sem) inode_lock(orphan_dir_inode) Since ip_alloc_sem is to protect allocation changes, which is unrelated with operations in ocfs2_del_inode_from_orphan. So move ocfs2_del_inode_from_orphan out of ip_alloc_sem to fix the deadlock.
CVSS metrics
5 scores · 5 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · ChainguardEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.43%
Chance of exploitation in the next 30 days
Percentile
37%
Versus all other CVEs
30-day change
0.00 pp
From 0.43% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-667Improper LockingThe product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
- CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
Affected systems
Ubuntu157 products
- linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136 | < 7.0.0-27.27
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64 | < 7.0.0-1008.8
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Chainguard9 products
- linux-aws-6.12< 6.12.85-r0
- linux-aws-6.18< 6.18.31-r0
- linux-azure-6.18< 6.18.31-r0
- linux-gcp-6.18< 6.18.31-r0
- linux-qemu-6.12< 6.12.85-r0
Linux2 products
- linux≥ a86a72a4a4e0ec109a98e2737948864ed6794bf7, < 297d8d7bb6a2bf133d3a3636edbdf94101cbd719 | ≥ a86a72a4a4e0ec109a98e2737948864ed6794bf7, < 32630dee18c6bb2175c8a865a474749492eaf19c | ≥ a86a72a4a4e0ec109a98e2737948864ed6794bf7, < 93f35419eb84d58820040642cb6e7528fe4aba7a | ≥ a86a72a4a4e0ec109a98e2737948864ed6794bf7, < 4b80b5a838a32437f2cae0662578bac216a2c51a | ≥ a86a72a4a4e0ec109a98e2737948864ed6794bf7, < 2b884d52273c60c298bd570163e8053657bbaff6 | ≥ a86a72a4a4e0ec109a98e2737948864ed6794bf7, < bc0fb5c7d54c78be43a536df0e20dee32adb27d3 | ≥ a86a72a4a4e0ec109a98e2737948864ed6794bf7, < f9fb1a7b635849322e1d7b7b6b26389778ec8e82 | ≥ a86a72a4a4e0ec109a98e2737948864ed6794bf7, < e049f7a9bd80b7319590789ea5e1c523d6339d91 | ≥ a86a72a4a4e0ec109a98e2737948864ed6794bf7, < b02da26a992db0c0e2559acbda0fc48d4a2fd337 | 4.6
- linux_kernel≥ 4.6, < 6.6.136 | ≥ 6.7, < 6.12.83 | ≥ 6.13, < 6.18.24 | ≥ 6.19, < 6.19.14 | ≥ 7.0, < 7.0.1
Debian1 product
- linux< 6.1.176-1 | < 6.12.85-1 | < 6.19.14-1
4 vendors · 169 products
