CVE-2026-68449

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

State: Published
Severity: Not scored
Published: Aug 12, 2026
Updated: Oct 30, 2026
Reserved: Jul 30, 2026

Description

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	62936009f35a6659cc3ebe0d90c754182d60da73 to before ea9fa4dabe476f85fe73df30a6ab61a23c22fda4Affected 62936009f35a6659cc3ebe0d90c754182d60da73 to before d72e8089dc332ac48293512ef0de77cbe0e04d25Affected 62936009f35a6659cc3ebe0d90c754182d60da73 to before 90e8cf489b593814b9398aa187ddbb790e33ec6fAffected 62936009f35a6659cc3ebe0d90c754182d60da73 to before 4c6e64cae2b2dab32ad9099faa339f6a72c0ce16Affected 62936009f35a6659cc3ebe0d90c754182d60da73 to before 8c5de0d8ab6824cfdadcbbe1be4c6c9d9f4c1f80Affected 62936009f35a6659cc3ebe0d90c754182d60da73 to before 1842d45f461a78988254631893329bdf4596e954Affected 62936009f35a6659cc3ebe0d90c754182d60da73 to before 29b916d3556bd12a95be7c56ca391b8cd572f8beAffected 62936009f35a6659cc3ebe0d90c754182d60da73 to before c2130f6553f4a5cbdc259de069600117a995f197Affected
LinuxLinux	2.6.36Affected before 2.6.36Not affected 5.10.265 through 5.10.Not affected 5.15.216 through 5.15.Not affected 6.1.191 through 6.1.Not affected 6.6.148 through 6.6.Not affected 6.12.101 through 6.12.Not affected 6.18.42 through 6.18.Not affected 7.1.6 through 7.1.*Not affected 7.2 and laterNot affected

Product

Versions

LinuxLinux

62936009f35a6659cc3ebe0d90c754182d60da73 to before ea9fa4dabe476f85fe73df30a6ab61a23c22fda4Affected
62936009f35a6659cc3ebe0d90c754182d60da73 to before d72e8089dc332ac48293512ef0de77cbe0e04d25Affected
62936009f35a6659cc3ebe0d90c754182d60da73 to before 90e8cf489b593814b9398aa187ddbb790e33ec6fAffected
62936009f35a6659cc3ebe0d90c754182d60da73 to before 4c6e64cae2b2dab32ad9099faa339f6a72c0ce16Affected
62936009f35a6659cc3ebe0d90c754182d60da73 to before 8c5de0d8ab6824cfdadcbbe1be4c6c9d9f4c1f80Affected
62936009f35a6659cc3ebe0d90c754182d60da73 to before 1842d45f461a78988254631893329bdf4596e954Affected
62936009f35a6659cc3ebe0d90c754182d60da73 to before 29b916d3556bd12a95be7c56ca391b8cd572f8beAffected
62936009f35a6659cc3ebe0d90c754182d60da73 to before c2130f6553f4a5cbdc259de069600117a995f197Affected

LinuxLinux

2.6.36Affected
before 2.6.36Not affected
5.10.265 through 5.10.*Not affected
5.15.216 through 5.15.*Not affected
6.1.191 through 6.1.*Not affected
6.6.148 through 6.6.*Not affected
6.12.101 through 6.12.*Not affected
6.18.42 through 6.18.*Not affected
7.1.6 through 7.1.*Not affected
7.2 and laterNot affected

References

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