CVE-2026-93254 (GCVE-0-2026-93254)
Vulnerability from cvelistv5
Published
2026-09-24 15:51
Modified
2026-10-19 09:08
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
arm64: entry: Avoid unnecessary local_irq_disable() on kernel exit
Currently, when exiting to kernel mode, we attempt involuntary
preemption. The preemption logic expects IRQs to be disabled, which is
why we call local_irq_disable() before attempting preemption.
However, depending on the context, local_irq_disable() may be
unnecessary:
- __el1_irq(), the non-NMI EL1 IRQ path, already has IRQs disabled, so
local_irq_disable() is redundant.
- irqentry_exit_to_kernel_mode_preempt() immediately returns when
exiting from an NMI-like context, so calling local_irq_disable()
beforehand is unnecessary work.
Furthermore, it confuses the pNMI state tracking when we are in a
context with interrupts disabled and the GIC_PRIO_PSR_I_SET bit is set
in the PMR, leading to a warning when
CONFIG_ARM64_DEBUG_PRIORITY_MASKING=y:
WARNING: ./arch/arm64/include/asm/irqflags.h:63 at arm64_exit_to_kernel_mode+0xb8/0xc0, CPU#40: retsnoop/31805
CPU: 40 UID: 0 PID: 31805 Comm: retsnoop Not tainted 7.2.0-rc6-next-20260805 #7 PREEMPTLAZY
pstate: 234013c9 (nzCv DAIF +PAN -UAO +TCO +DIT +SSBS BTYPE=--)
pc : arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63)
lr : el1_abort (arch/arm64/kernel/entry-common.c:323)
pmr: 000000f0
Call trace:
arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63) (P)
el1_abort (arch/arm64/kernel/entry-common.c:323)
el1h_64_sync_handler (arch/arm64/kernel/entry-common.c:449)
el1h_64_sync (arch/arm64/kernel/entry.S:589)
[...]
Split arm64_exit_to_kernel_mode() into preempt, non-preempt, and
dispatch parts so that we can avoid this extra work where it is not
needed and avoid breaking the pNMI tracking logic.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"arch/arm64/kernel/entry-common.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "49a61174186bed25d439ff37400c7ce5e3603e73",
"status": "affected",
"version": "ae654112eac05f316ef31587fc55e4d7160d0086",
"versionType": "git"
},
{
"lessThan": "39aebe0e89469c2904e60b1e977e0d4dbf33326b",
"status": "affected",
"version": "ae654112eac05f316ef31587fc55e4d7160d0086",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"arch/arm64/kernel/entry-common.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "7.1"
},
{
"lessThan": "7.1",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.6",
"versionStartIncluding": "7.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "7.1",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: entry: Avoid unnecessary local_irq_disable() on kernel exit\n\nCurrently, when exiting to kernel mode, we attempt involuntary\npreemption. The preemption logic expects IRQs to be disabled, which is\nwhy we call local_irq_disable() before attempting preemption.\n\nHowever, depending on the context, local_irq_disable() may be\nunnecessary:\n\n- __el1_irq(), the non-NMI EL1 IRQ path, already has IRQs disabled, so\n local_irq_disable() is redundant.\n\n- irqentry_exit_to_kernel_mode_preempt() immediately returns when\n exiting from an NMI-like context, so calling local_irq_disable()\n beforehand is unnecessary work.\n\nFurthermore, it confuses the pNMI state tracking when we are in a\ncontext with interrupts disabled and the GIC_PRIO_PSR_I_SET bit is set\nin the PMR, leading to a warning when\nCONFIG_ARM64_DEBUG_PRIORITY_MASKING=y:\n\n WARNING: ./arch/arm64/include/asm/irqflags.h:63 at arm64_exit_to_kernel_mode+0xb8/0xc0, CPU#40: retsnoop/31805\n CPU: 40 UID: 0 PID: 31805 Comm: retsnoop Not tainted 7.2.0-rc6-next-20260805 #7 PREEMPTLAZY\n pstate: 234013c9 (nzCv DAIF +PAN -UAO +TCO +DIT +SSBS BTYPE=--)\n pc : arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63)\n lr : el1_abort (arch/arm64/kernel/entry-common.c:323)\n pmr: 000000f0\n Call trace:\n arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63) (P)\n el1_abort (arch/arm64/kernel/entry-common.c:323)\n el1h_64_sync_handler (arch/arm64/kernel/entry-common.c:449)\n el1h_64_sync (arch/arm64/kernel/entry.S:589)\n [...]\n\nSplit arm64_exit_to_kernel_mode() into preempt, non-preempt, and\ndispatch parts so that we can avoid this extra work where it is not\nneeded and avoid breaking the pNMI tracking logic."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-19T09:08:07.781Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/49a61174186bed25d439ff37400c7ce5e3603e73"
},
{
"url": "https://git.kernel.org/stable/c/39aebe0e89469c2904e60b1e977e0d4dbf33326b"
}
],
"title": "arm64: entry: Avoid unnecessary local_irq_disable() on kernel exit",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-93254",
"datePublished": "2026-09-24T15:51:40.955Z",
"dateReserved": "2026-09-17T16:02:15.096Z",
"dateUpdated": "2026-10-19T09:08:07.781Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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