In the Linux kernel, the following vulnerability has been resolved: ublk: reset per-IO canceled flag on each fetch If a ublk server starts… (CVE-2026-53124)
A vulnerability in the Linux kernel's ublk subsystem involves improper resetting of per-IO canceled flags during IO fetch operations. If a ublk server crashes before fetching all IOs, some fetch commands may never be properly canceled, causing outstanding commands to remain uncompleted. This issue has been fixed by resetting the per-IO canceled flags immediately upon each IO fetch rather than waiting for all IOs in a queue to be fetched.
AI Analysis
Technical Summary
The Linux kernel's ublk subsystem had a vulnerability where the per-IO canceled flag was only reset after all IOs in a queue were fetched. If the ublk server crashed after fetching only a subset of IOs, the cancellation of those fetch commands would not complete because their canceled flags remained set. This prevented the ublk_cancel_cmd function from calling io_uring_cmd_done on those commands, leaving them outstanding indefinitely. The fix involves resetting the per-IO canceled flag immediately when each IO is fetched, ensuring proper cancellation even if the server dies mid-recovery.
Potential Impact
This vulnerability can cause IO commands to remain outstanding indefinitely if the ublk server crashes during device recovery, potentially leading to denial of service or degraded IO functionality. There is no impact on confidentiality or integrity. The CVSS vector indicates local attack complexity with low privileges required and no user interaction, resulting in no confidentiality or integrity impact but high availability impact.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, monitoring for ublk server crashes and ensuring stable operation may help reduce exposure. Apply official Linux kernel updates once they include the fix for CVE-2026-53124.
In the Linux kernel, the following vulnerability has been resolved: ublk: reset per-IO canceled flag on each fetch If a ublk server starts… (CVE-2026-53124)
Description
A vulnerability in the Linux kernel's ublk subsystem involves improper resetting of per-IO canceled flags during IO fetch operations. If a ublk server crashes before fetching all IOs, some fetch commands may never be properly canceled, causing outstanding commands to remain uncompleted. This issue has been fixed by resetting the per-IO canceled flags immediately upon each IO fetch rather than waiting for all IOs in a queue to be fetched.
CVSS v3.1
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel's ublk subsystem had a vulnerability where the per-IO canceled flag was only reset after all IOs in a queue were fetched. If the ublk server crashed after fetching only a subset of IOs, the cancellation of those fetch commands would not complete because their canceled flags remained set. This prevented the ublk_cancel_cmd function from calling io_uring_cmd_done on those commands, leaving them outstanding indefinitely. The fix involves resetting the per-IO canceled flag immediately when each IO is fetched, ensuring proper cancellation even if the server dies mid-recovery.
Potential Impact
This vulnerability can cause IO commands to remain outstanding indefinitely if the ublk server crashes during device recovery, potentially leading to denial of service or degraded IO functionality. There is no impact on confidentiality or integrity. The CVSS vector indicates local attack complexity with low privileges required and no user interaction, resulting in no confidentiality or integrity impact but high availability impact.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, monitoring for ublk server crashes and ensuring stable operation may help reduce exposure. Apply official Linux kernel updates once they include the fix for CVE-2026-53124.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-xq85-jg4p-xf7w
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-53124"]
- Ecosystems
- []
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6a629b0f9c2644c7f8d86402
Added to database: 07/23/2026, 22:51:59 UTC
Last enriched: 07/23/2026, 22:54:23 UTC
Last updated: 07/28/2026, 20:52:04 UTC
Views: 4
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