CVE-2026-68449 json
ata: sata_dwc_460ex: fix infinite loop in NCQ tag completion bit-scanning
published 2026-08-12 2 mo ago modified 2026-10-30 9 d ago also EUVD-2026-57055
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 5%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Linux Linux 5.10.265, 5.15.216, 6.1.191, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2
- linux Debian 13 6.12.101-1
- linux Debian 14 7.1.6-1
- linux-6.12 Debian 12 6.12.101-1~deb12u1
debian advisories DEBIAN-CVE-2026-68449
- linux Ubuntu 22.04 LTS 5.15.0-198.208
- linux Ubuntu 24.04 LTS 6.8.0-147.147
- linux Ubuntu 26.04 LTS 7.0.0-38.38
- linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
- linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
- linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
- linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
- linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79
ubuntu advisories UBUNTU-CVE-2026-68449
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- git.kernel.org/stable/c/ea9fa4dabe476f85fe73df30a6ab61a23c22fda4 commit
- git.kernel.org/stable/c/d72e8089dc332ac48293512ef0de77cbe0e04d25 commit
- git.kernel.org/stable/c/90e8cf489b593814b9398aa187ddbb790e33ec6f commit
- git.kernel.org/stable/c/4c6e64cae2b2dab32ad9099faa339f6a72c0ce16 commit
- git.kernel.org/stable/c/8c5de0d8ab6824cfdadcbbe1be4c6c9d9f4c1f80 commit
- git.kernel.org/stable/c/1842d45f461a78988254631893329bdf4596e954 commit
- git.kernel.org/stable/c/29b916d3556bd12a95be7c56ca391b8cd572f8be commit
- git.kernel.org/stable/c/c2130f6553f4a5cbdc259de069600117a995f197 commit
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-68449 updated cvss 5.5
kernel: ata: sata_dwc_460ex: fix infinite loop in NCQ tag completion bit-scanning
-
Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +9 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +30 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +84 more Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9affected: no fix available “Fix deferred”
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Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +2 more Red Hat Enterprise Linux 10 kernel 6.12.0-55.94.1.el10_0 Red Hat Enterprise Linux for NVIDIA 26 kernel 6.12.0-55.94.1.el10_0 Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8not affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
0.17% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/ea9fa4dabe476f85fe73df30a6ab61a23c22fda4
- git.kernel.org /stable/c/d72e8089dc332ac48293512ef0de77cbe0e04d25
- git.kernel.org /stable/c/90e8cf489b593814b9398aa187ddbb790e33ec6f
- git.kernel.org /stable/c/4c6e64cae2b2dab32ad9099faa339f6a72c0ce16
- git.kernel.org /stable/c/8c5de0d8ab6824cfdadcbbe1be4c6c9d9f4c1f80
- git.kernel.org /stable/c/1842d45f461a78988254631893329bdf4596e954
- git.kernel.org /stable/c/29b916d3556bd12a95be7c56ca391b8cd572f8be
- git.kernel.org /stable/c/c2130f6553f4a5cbdc259de069600117a995f197
Sources
- CVE List CVE-2026-68449
- NVD CVE-2026-68449
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