In the Linux kernel, the following vulnerability has been resolved: btrfs: fix deadlock between reflink and transaction commit when using… (CVE-2026-53122)
A deadlock vulnerability in the Linux kernel's Btrfs filesystem was resolved. The issue occurs when using the flushoncommit mount option, causing a deadlock between reflink operations and transaction commits. This deadlock arises due to locking conflicts when copying inline extents beyond the current file size and flushing delayed allocations. The vulnerability can cause tasks to block indefinitely, impacting system availability.
AI Analysis
Technical Summary
The vulnerability in the Linux kernel Btrfs filesystem involves a deadlock condition triggered when the flushoncommit mount option is enabled. Specifically, a reflink operation copying an inline extent beyond the destination inode's current size locks certain inode ranges while a concurrent transaction commit attempts to flush delayed allocations and invalidate folios. This results in two tasks waiting on each other: one waiting for the transaction commit to complete, and the other waiting for the extent lock held by the first task. This deadlock can cause kernel tasks to block indefinitely, leading to potential system hangs or degraded availability. The issue was reported by Syzbot with detailed stack traces illustrating the blocking behavior. The vulnerability is tracked as CVE-2026-53122 and categorized under CWE-667 (Improper Locking).
Potential Impact
The vulnerability causes a deadlock in the Linux kernel Btrfs filesystem when using the flushoncommit mount option, resulting in kernel tasks blocking indefinitely. This can lead to system hangs or degraded availability but does not affect confidentiality or integrity. There is no indication of data corruption or privilege escalation. The impact is limited to denial of service via resource deadlock.
Mitigation Recommendations
A fix for this deadlock vulnerability has been implemented in the Linux kernel. Users should update to the patched kernel version that resolves CVE-2026-53122. Since this is a kernel-level issue, applying the official kernel update from the vendor or distribution is the recommended remediation. No additional mitigations are specified or required beyond applying the patch.
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix deadlock between reflink and transaction commit when using… (CVE-2026-53122)
Description
A deadlock vulnerability in the Linux kernel's Btrfs filesystem was resolved. The issue occurs when using the flushoncommit mount option, causing a deadlock between reflink operations and transaction commits. This deadlock arises due to locking conflicts when copying inline extents beyond the current file size and flushing delayed allocations. The vulnerability can cause tasks to block indefinitely, impacting system availability.
CVSS v3.1
Score 5.5medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in the Linux kernel Btrfs filesystem involves a deadlock condition triggered when the flushoncommit mount option is enabled. Specifically, a reflink operation copying an inline extent beyond the destination inode's current size locks certain inode ranges while a concurrent transaction commit attempts to flush delayed allocations and invalidate folios. This results in two tasks waiting on each other: one waiting for the transaction commit to complete, and the other waiting for the extent lock held by the first task. This deadlock can cause kernel tasks to block indefinitely, leading to potential system hangs or degraded availability. The issue was reported by Syzbot with detailed stack traces illustrating the blocking behavior. The vulnerability is tracked as CVE-2026-53122 and categorized under CWE-667 (Improper Locking).
Potential Impact
The vulnerability causes a deadlock in the Linux kernel Btrfs filesystem when using the flushoncommit mount option, resulting in kernel tasks blocking indefinitely. This can lead to system hangs or degraded availability but does not affect confidentiality or integrity. There is no indication of data corruption or privilege escalation. The impact is limited to denial of service via resource deadlock.
Mitigation Recommendations
A fix for this deadlock vulnerability has been implemented in the Linux kernel. Users should update to the patched kernel version that resolves CVE-2026-53122. Since this is a kernel-level issue, applying the official kernel update from the vendor or distribution is the recommended remediation. No additional mitigations are specified or required beyond applying the patch.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_vex
- Csaf Version
- 2.0
- Publisher
- Microsoft Security Response Center
- Advisory Id
- msrc_CVE-2026-53122
- Cve Count
- 1
- Additional Cves
- []
- Cvss Version
- 3.1
Threat ID: 6a42ed8427e9c7971994f309
Added to database: 06/29/2026, 22:11:16 UTC
Last enriched: 07/23/2026, 22:57:12 UTC
Last updated: 07/31/2026, 19:24:49 UTC
Views: 6
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