Bug 2514463 (CVE-2026-68449) - CVE-2026-68449 kernel: ata: sata_dwc_460ex: fix infinite loop in NCQ tag completion bit-scanning
Summary: CVE-2026-68449 kernel: ata: sata_dwc_460ex: fix infinite loop in NCQ tag comp...
Keywords:
Status: NEW
Alias: CVE-2026-68449
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-12 01:11 UTC by OSIDB Bzimport
Modified: 2026-08-13 09:10 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-08-12 01:11:15 UTC
In the Linux kernel, the following vulnerability has been resolved:

ata: sata_dwc_460ex: fix infinite loop in NCQ tag completion bit-scanning

The hand-rolled bit-scanning loop in the NCQ completion path has an
infinite loop bug.  When tag_mask has only high bits set (e.g.
0x80000000), the inner while loop left-shifts tag_mask until it
overflows to 0.  At that point !(0 & 1) is always true and 0 <<= 1
stays 0, causing an infinite loop in hardirq context with a spinlock
held.

Replace the open-coded bit-scanning with __ffs() which correctly
finds the least significant set bit and is bounded by the width of
the argument.


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