CVE-2026-80626

In the Linux kernel, the following vulnerability has been resolved: powerpc/perf: fix preempt count underflow in fsl_emb_pmu_del fsl_emb_pmu_del() unconditionally calls put_cpu_var(cpu_hw_events) at the 'out:' label, but only calls the matching get_cpu_var() after the 'i < 0' early-return check. When event->hw.idx is negative the function jumps to 'out:' without having taken get_cpu_var(), and the trailing put_cpu_var() then issues an unmatched preempt_enable(), underflowing preempt_count. On a CONFIG_PREEMPT=y kernel preempt_count would underflow and eventually present as a 'scheduling while atomic' BUG. Move put_cpu_var() to pair with get_cpu_var() so the percpu access is correctly bracketed and the 'out:' label only handles perf_pmu_enable.

CVSS

No CVSS.

References

Link	Resource
https://git.kernel.org/stable/c/5397142d60aa29dcf636f5459d960bfc4f97c42a
https://git.kernel.org/stable/c/67aeb1eb93d4ffd898a3e74a7f3fe46ee71feb28
https://git.kernel.org/stable/c/73711688479df333acc134e3730fff1acba1843e
https://git.kernel.org/stable/c/81e3a86030462824a67d697739cf3f387f4ba350
https://git.kernel.org/stable/c/9a515e00b00132b6fc3f1dd62dc5204bbda8cb10
https://git.kernel.org/stable/c/b504fd953664c3f4d176ae8cb594adb3fda9d577
https://git.kernel.org/stable/c/b89477077c834d94381c7bf07d81193bebefcff9
https://git.kernel.org/stable/c/c0c7722308c5f303117d8bd555290fdf26b098da

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-28 08:16

Updated : 2026-08-28 08:16

NVD link : CVE-2026-80626

Mitre link : CVE-2026-80626

CVE.ORG link : CVE-2026-80626

JSON object : View

Products Affected

No product.

CWE

No CWE.

{"id": "CVE-2026-80626", "cveTags": [], "metrics": {}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "a11106544f33c104706ae42d27219a409b67478e", "lessThan": "c0c7722308c5f303117d8bd555290fdf26b098da", "versionType": "git"}, {"status": "affected", "version": "a11106544f33c104706ae42d27219a409b67478e", "lessThan": "67aeb1eb93d4ffd898a3e74a7f3fe46ee71feb28", "versionType": "git"}, {"status": "affected", "version": "a11106544f33c104706ae42d27219a409b67478e", "lessThan": "9a515e00b00132b6fc3f1dd62dc5204bbda8cb10", "versionType": "git"}, {"status": "affected", "version": "a11106544f33c104706ae42d27219a409b67478e", "lessThan": "5397142d60aa29dcf636f5459d960bfc4f97c42a", "versionType": "git"}, {"status": "affected", "version": "a11106544f33c104706ae42d27219a409b67478e", "lessThan": "b89477077c834d94381c7bf07d81193bebefcff9", "versionType": "git"}, {"status": "affected", "version": "a11106544f33c104706ae42d27219a409b67478e", "lessThan": "73711688479df333acc134e3730fff1acba1843e", "versionType": "git"}, {"status": "affected", "version": "a11106544f33c104706ae42d27219a409b67478e", "lessThan": "b504fd953664c3f4d176ae8cb594adb3fda9d577", "versionType": "git"}, {"status": "affected", "version": "a11106544f33c104706ae42d27219a409b67478e", "lessThan": "81e3a86030462824a67d697739cf3f387f4ba350", "versionType": "git"}], "programFiles": ["arch/powerpc/perf/core-fsl-emb.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "2.6.34"}, {"status": "unaffected", "version": "0", "lessThan": "2.6.34", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.261", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.212", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.178", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.145", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.97", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.40", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.5", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["arch/powerpc/perf/core-fsl-emb.c"], "defaultStatus": "affected"}]}], "published": "2026-08-28T08:16:46.740", "references": [{"url": "https://git.kernel.org/stable/c/5397142d60aa29dcf636f5459d960bfc4f97c42a", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/67aeb1eb93d4ffd898a3e74a7f3fe46ee71feb28", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/73711688479df333acc134e3730fff1acba1843e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/81e3a86030462824a67d697739cf3f387f4ba350", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/9a515e00b00132b6fc3f1dd62dc5204bbda8cb10", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b504fd953664c3f4d176ae8cb594adb3fda9d577", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b89477077c834d94381c7bf07d81193bebefcff9", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c0c7722308c5f303117d8bd555290fdf26b098da", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Received", "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/perf: fix preempt count underflow in fsl_emb_pmu_del\n\nfsl_emb_pmu_del() unconditionally calls put_cpu_var(cpu_hw_events) at\nthe 'out:' label, but only calls the matching get_cpu_var() after the\n'i < 0' early-return check. When event->hw.idx is negative the\nfunction jumps to 'out:' without having taken get_cpu_var(), and the\ntrailing put_cpu_var() then issues an unmatched preempt_enable(),\nunderflowing preempt_count.\n\nOn a CONFIG_PREEMPT=y kernel preempt_count would underflow and\neventually present as a 'scheduling while atomic' BUG.\n\nMove put_cpu_var() to pair with get_cpu_var() so the percpu access is\ncorrectly bracketed and the 'out:' label only handles perf_pmu_enable."}], "lastModified": "2026-08-28T08:16:46.740", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}