CVE-2026-98888 (GCVE-0-2026-98888)
Vulnerability from cvelistv5 – Published: 2026-10-23 11:37 – Updated: 2026-10-23 11:37
VLAI
EPSS
VEX
Title
arm64: kprobes: Allow reentering kprobes while single-stepping
Summary
In the Linux kernel, the following vulnerability has been resolved:
arm64: kprobes: Allow reentering kprobes while single-stepping
A kprobe can be hit while another kprobe is in KPROBE_HIT_SS state. This
can happen when tracing or perf code runs from the debug exception path
while the first kprobe is preparing or executing its out-of-line
single-step instruction.
Currently arm64 treats a kprobe hit in KPROBE_HIT_SS as unrecoverable,
the same as a hit in KPROBE_REENTER. This is too strict. A hit in
KPROBE_HIT_SS is still a one-level reentry and can be handled by saving
the current kprobe state and setting up single-step for the new probe,
just like reentry from KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE.
The truly unrecoverable case is hitting another kprobe while already in
KPROBE_REENTER, because the reentry save area has already been consumed.
Move KPROBE_HIT_SS to the recoverable reentry cases and leave
KPROBE_REENTER as the unrecoverable nested reentry case.
This change also requires saving saved_irqflag in struct prev_kprobe.
When a nested kprobe calls kprobes_save_local_irqflag(), it overwrites
kcb->saved_irqflag with the currently masked DAIF value, losing the
outer kprobe's original DAIF state. Without this fix, when the outer
kprobe's single-step finishes, kprobes_restore_local_irqflag() applies
the wrong DAIF mask and leaves interrupts permanently disabled.
Extend struct prev_kprobe with a saved_irqflag field and save/restore it
alongside kp and status. This ensures the outer kprobe's original
interrupt state is preserved across reentry.
This mirrors the x86 fix in commit 6a5022a56ac3
("kprobes/x86: Allow to handle reentered kprobe on single-stepping").
Severity
No CVSS data available.
Assigner
References
7 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < bb0fe9121aa0824211aafa33c7d0151fd25ddb75
(git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < f96a0606de6bcc8d937b80e6470fd7a174c17e26 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 1f342b3e44c3035a837b53b217d816f7511c0d0a (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < c8e84e292ed4cfc199824146da71bb4397b02a1f (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 68774caca799e9695db56d426c69acebd041c2ed (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < a21bf9cb893126e8d9730995708d0be5eb167652 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 23f851ac0078a908bf3422d6467ebc1db5828c46 (git) Affected: 0 , < 5.10.271 (semver) Affected: 0 , < 5.15.222 (semver) Affected: 0 , < 6.1.189 (semver) Affected: 0 , < 6.6.158 (semver) Affected: 0 , < 6.12.111 (semver) Affected: 0 , < 6.18.53 (semver) |
guessed | |
| Linux | Linux |
Unaffected:
5.10.271 , ≤ 5.10.*
(semver)
Unaffected: 5.15.222 , ≤ 5.15.* (semver) Unaffected: 6.1.189 , ≤ 6.1.* (semver) Unaffected: 6.6.158 , ≤ 6.6.* (semver) Unaffected: 6.12.111 , ≤ 6.12.* (semver) Unaffected: 6.18.53 , ≤ 6.18.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
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"version": "0",
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}
]
},
{
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"product": "Linux",
"programFiles": [
"arch/arm64/include/asm/kprobes.h",
"arch/arm64/kernel/probes/kprobes.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.271",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.271",
"vulnerable": true
},
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"versionEndExcluding": "6.12.111",
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{
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{
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}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: kprobes: Allow reentering kprobes while single-stepping\n\nA kprobe can be hit while another kprobe is in KPROBE_HIT_SS state. This\ncan happen when tracing or perf code runs from the debug exception path\nwhile the first kprobe is preparing or executing its out-of-line\nsingle-step instruction.\n\nCurrently arm64 treats a kprobe hit in KPROBE_HIT_SS as unrecoverable,\nthe same as a hit in KPROBE_REENTER. This is too strict. A hit in\nKPROBE_HIT_SS is still a one-level reentry and can be handled by saving\nthe current kprobe state and setting up single-step for the new probe,\njust like reentry from KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE.\n\nThe truly unrecoverable case is hitting another kprobe while already in\nKPROBE_REENTER, because the reentry save area has already been consumed.\n\nMove KPROBE_HIT_SS to the recoverable reentry cases and leave\nKPROBE_REENTER as the unrecoverable nested reentry case.\n\nThis change also requires saving saved_irqflag in struct prev_kprobe.\nWhen a nested kprobe calls kprobes_save_local_irqflag(), it overwrites\nkcb-\u003esaved_irqflag with the currently masked DAIF value, losing the\nouter kprobe\u0027s original DAIF state. Without this fix, when the outer\nkprobe\u0027s single-step finishes, kprobes_restore_local_irqflag() applies\nthe wrong DAIF mask and leaves interrupts permanently disabled.\n\nExtend struct prev_kprobe with a saved_irqflag field and save/restore it\nalongside kp and status. This ensures the outer kprobe\u0027s original\ninterrupt state is preserved across reentry.\n\nThis mirrors the x86 fix in commit 6a5022a56ac3\n(\"kprobes/x86: Allow to handle reentered kprobe on single-stepping\")."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-23T11:37:46.984Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/bb0fe9121aa0824211aafa33c7d0151fd25ddb75"
},
{
"url": "https://git.kernel.org/stable/c/f96a0606de6bcc8d937b80e6470fd7a174c17e26"
},
{
"url": "https://git.kernel.org/stable/c/1f342b3e44c3035a837b53b217d816f7511c0d0a"
},
{
"url": "https://git.kernel.org/stable/c/c8e84e292ed4cfc199824146da71bb4397b02a1f"
},
{
"url": "https://git.kernel.org/stable/c/68774caca799e9695db56d426c69acebd041c2ed"
},
{
"url": "https://git.kernel.org/stable/c/a21bf9cb893126e8d9730995708d0be5eb167652"
},
{
"url": "https://git.kernel.org/stable/c/23f851ac0078a908bf3422d6467ebc1db5828c46"
}
],
"title": "arm64: kprobes: Allow reentering kprobes while single-stepping",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-98888",
"datePublished": "2026-10-23T11:37:46.984Z",
"dateReserved": "2026-09-25T10:25:14.378Z",
"dateUpdated": "2026-10-23T11:37:46.984Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-98888",
"date": "2026-10-24",
"epss": "0.00215",
"percentile": "0.11286"
},
"microsoft_vex": {
"current_release_date": "2026-10-24T01:05:18.000Z",
"cve": "CVE-2026-98888",
"id": "msrc_CVE-2026-98888",
"initial_release_date": "2026-10-24T01:04:09.000Z",
"product_status:known_affected": "1",
"product_status:under_investigation": "1",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "arm64: kprobes: Allow reentering kprobes while single-stepping",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-98888.json",
"version": "2"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
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"product": "Linux",
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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"versionType": "git"
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{
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"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
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"status": "affected",
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"versionType": "git"
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"status": "affected",
"version": "0",
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"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
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"version": "5.10.271",
"versionType": "semver"
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{
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"status": "unaffected",
"version": "5.15.222",
"versionType": "semver"
},
{
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},
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"versionType": "semver"
},
{
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},
{
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"version": "7.2",
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}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: kprobes: Allow reentering kprobes while single-stepping\n\nA kprobe can be hit while another kprobe is in KPROBE_HIT_SS state. This\ncan happen when tracing or perf code runs from the debug exception path\nwhile the first kprobe is preparing or executing its out-of-line\nsingle-step instruction.\n\nCurrently arm64 treats a kprobe hit in KPROBE_HIT_SS as unrecoverable,\nthe same as a hit in KPROBE_REENTER. This is too strict. A hit in\nKPROBE_HIT_SS is still a one-level reentry and can be handled by saving\nthe current kprobe state and setting up single-step for the new probe,\njust like reentry from KPROBE_HIT_ACTIVE or KPROBE_HIT_SSDONE.\n\nThe truly unrecoverable case is hitting another kprobe while already in\nKPROBE_REENTER, because the reentry save area has already been consumed.\n\nMove KPROBE_HIT_SS to the recoverable reentry cases and leave\nKPROBE_REENTER as the unrecoverable nested reentry case.\n\nThis change also requires saving saved_irqflag in struct prev_kprobe.\nWhen a nested kprobe calls kprobes_save_local_irqflag(), it overwrites\nkcb-\u003esaved_irqflag with the currently masked DAIF value, losing the\nouter kprobe\u0027s original DAIF state. Without this fix, when the outer\nkprobe\u0027s single-step finishes, kprobes_restore_local_irqflag() applies\nthe wrong DAIF mask and leaves interrupts permanently disabled.\n\nExtend struct prev_kprobe with a saved_irqflag field and save/restore it\nalongside kp and status. This ensures the outer kprobe\u0027s original\ninterrupt state is preserved across reentry.\n\nThis mirrors the x86 fix in commit 6a5022a56ac3\n(\"kprobes/x86: Allow to handle reentered kprobe on single-stepping\")."
}
],
"id": "CVE-2026-98888",
"lastModified": "2026-10-23T12:18:22.583",
"metrics": {},
"published": "2026-10-23T12:18:22.583",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1f342b3e44c3035a837b53b217d816f7511c0d0a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/23f851ac0078a908bf3422d6467ebc1db5828c46"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/68774caca799e9695db56d426c69acebd041c2ed"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a21bf9cb893126e8d9730995708d0be5eb167652"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/bb0fe9121aa0824211aafa33c7d0151fd25ddb75"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c8e84e292ed4cfc199824146da71bb4397b02a1f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f96a0606de6bcc8d937b80e6470fd7a174c17e26"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
}
}
}
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.