CVE-2026-93191 (GCVE-0-2026-93191)
Vulnerability from cvelistv5 – Published: 2026-09-17 16:12 – Updated: 2026-09-17 16:12
VLAI
EPSS
VEX
Title
smack: fix incorrect task context in smack_msg_queue_msgrcv
Summary
In the Linux kernel, the following vulnerability has been resolved:
smack: fix incorrect task context in smack_msg_queue_msgrcv
The smack_msg_queue_msgrcv() function incorrectly checks
the permissions of the 'current' task instead of the
'target' task.
In the msgsnd() syscall path, if a receiver is already waiting,
the pipelined_send() optimization is used to push the message
directly to the receiver task:
ipc/msg.c`pipelined_send():
` smp_store_release(&msr->r_msg, msg)
In this case, the 'sender' (current) task performs the check
on behalf of the 'receiver' task (msr->r_tsk, passed as the
'target' parameter):
ipc/msg.c`pipelined_send():
` security_msg_queue_msgrcv(,, target := msr->r_tsk,,)
However, smack_msg_queue_msgrcv() ignores the 'target' and
checks 'current':
smack_msg_queue_msgrcv(…)
` smk_curacc_msq(isp, MAY_READWRITE); // current task
'current' MAY satisfy smack_msg_queue_msgrcv r/w requirement,
but 'target' (the receiver task) might NOT;
as a result, an unauthorized receiver gets the message,
violating MAC policy.
Test:
1) create a sysv message queue with label “foo”
2) echo "bar foo r" >/smack/load2
3) msgrcv(,,,0,MSG_NOERROR) in "bar"-labeled task.
The task is waiting for the messages ...
4) msgsnd() from a "foo"-labeled task:
"bar"-labeled task gets the message.
This patch fixes the issue by checking permission on the
'target' task instead of 'current'.
(2008-02-04, Casey Schaufler)
Severity
No CVSS data available.
Assigner
References
8 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
e114e473771c848c3cfec05f0123e70f1cdbdc99 , < 4e49f997ef0c569e09b42aab6bd38c7c54ea095d
(git)
Affected: e114e473771c848c3cfec05f0123e70f1cdbdc99 , < dbece6c2f80b0470d8d99d7a016827dce99ed6e3 (git) Affected: e114e473771c848c3cfec05f0123e70f1cdbdc99 , < 7be4bd21c50afa83c93799b0f16cf5bfa493194e (git) Affected: e114e473771c848c3cfec05f0123e70f1cdbdc99 , < ec47f4177046dfaaf1cebb15f4d2e7b543475daf (git) Affected: e114e473771c848c3cfec05f0123e70f1cdbdc99 , < e35dc5a4ed6d1e536382d80c685187511ff248a1 (git) Affected: e114e473771c848c3cfec05f0123e70f1cdbdc99 , < c2ab27c2e11591524b1378c24ad18882a425d1fa (git) Affected: e114e473771c848c3cfec05f0123e70f1cdbdc99 , < d02c55e3ea82e41ea2c2026e08201e5daa4d0cfe (git) Affected: e114e473771c848c3cfec05f0123e70f1cdbdc99 , < fba3d32825f4bbc8e20f0cdc3b14df57965b8fe5 (git) |
guessed | |
| Linux | Linux |
Affected:
2.6.25
Unaffected: 0 , < 2.6.25 (semver) Unaffected: 5.10.270 , ≤ 5.10.* (semver) Unaffected: 5.15.221 , ≤ 5.15.* (semver) Unaffected: 6.1.188 , ≤ 6.1.* (semver) Unaffected: 6.6.157 , ≤ 6.6.* (semver) Unaffected: 6.12.110 , ≤ 6.12.* (semver) Unaffected: 6.18.52 , ≤ 6.18.* (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"security/smack/smack_lsm.c"
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"versionType": "git"
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"versionType": "git"
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{
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"version": "e114e473771c848c3cfec05f0123e70f1cdbdc99",
"versionType": "git"
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{
"lessThan": "d02c55e3ea82e41ea2c2026e08201e5daa4d0cfe",
"status": "affected",
"version": "e114e473771c848c3cfec05f0123e70f1cdbdc99",
"versionType": "git"
},
{
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"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.25"
},
{
"lessThan": "2.6.25",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.270",
"versionStartIncluding": "2.6.25",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.221",
"versionStartIncluding": "2.6.25",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.188",
"versionStartIncluding": "2.6.25",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.157",
"versionStartIncluding": "2.6.25",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.110",
"versionStartIncluding": "2.6.25",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.52",
"versionStartIncluding": "2.6.25",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.6",
"versionStartIncluding": "2.6.25",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3-rc1",
"versionStartIncluding": "2.6.25",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmack: fix incorrect task context in smack_msg_queue_msgrcv\n\nThe smack_msg_queue_msgrcv() function incorrectly checks\nthe permissions of the \u0027current\u0027 task instead of the\n\u0027target\u0027 task.\n\nIn the msgsnd() syscall path, if a receiver is already waiting,\nthe pipelined_send() optimization is used to push the message\ndirectly to the receiver task:\n\n ipc/msg.c`pipelined_send():\n ` smp_store_release(\u0026msr-\u003er_msg, msg)\n\nIn this case, the \u0027sender\u0027 (current) task performs the check\non behalf of the \u0027receiver\u0027 task (msr-\u003er_tsk, passed as the\n\u0027target\u0027 parameter):\n\n ipc/msg.c`pipelined_send():\n ` security_msg_queue_msgrcv(,, target := msr-\u003er_tsk,,)\n\nHowever, smack_msg_queue_msgrcv() ignores the \u0027target\u0027 and\nchecks \u0027current\u0027:\n\n smack_msg_queue_msgrcv(\u2026)\n ` smk_curacc_msq(isp, MAY_READWRITE); // current task\n\n\u0027current\u0027 MAY satisfy smack_msg_queue_msgrcv r/w requirement,\nbut \u0027target\u0027 (the receiver task) might NOT;\nas a result, an unauthorized receiver gets the message,\nviolating MAC policy.\n\nTest:\n1) create a sysv message queue with label \u201cfoo\u201d\n2) echo \"bar foo r\" \u003e/smack/load2\n3) msgrcv(,,,0,MSG_NOERROR) in \"bar\"-labeled task.\n The task is waiting for the messages ...\n4) msgsnd() from a \"foo\"-labeled task:\n\"bar\"-labeled task gets the message.\n\nThis patch fixes the issue by checking permission on the\n\u0027target\u0027 task instead of \u0027current\u0027.\n\n(2008-02-04, Casey Schaufler)"
}
],
"providerMetadata": {
"dateUpdated": "2026-09-17T16:12:15.765Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/4e49f997ef0c569e09b42aab6bd38c7c54ea095d"
},
{
"url": "https://git.kernel.org/stable/c/dbece6c2f80b0470d8d99d7a016827dce99ed6e3"
},
{
"url": "https://git.kernel.org/stable/c/7be4bd21c50afa83c93799b0f16cf5bfa493194e"
},
{
"url": "https://git.kernel.org/stable/c/ec47f4177046dfaaf1cebb15f4d2e7b543475daf"
},
{
"url": "https://git.kernel.org/stable/c/e35dc5a4ed6d1e536382d80c685187511ff248a1"
},
{
"url": "https://git.kernel.org/stable/c/c2ab27c2e11591524b1378c24ad18882a425d1fa"
},
{
"url": "https://git.kernel.org/stable/c/d02c55e3ea82e41ea2c2026e08201e5daa4d0cfe"
},
{
"url": "https://git.kernel.org/stable/c/fba3d32825f4bbc8e20f0cdc3b14df57965b8fe5"
}
],
"title": "smack: fix incorrect task context in smack_msg_queue_msgrcv",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-93191",
"datePublished": "2026-09-17T16:12:15.765Z",
"dateReserved": "2026-09-17T16:02:15.092Z",
"dateUpdated": "2026-09-17T16:12:15.765Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-93191\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-17T17:18:15.307\",\"lastModified\":\"2026-09-17T17:18:15.307\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nsmack: fix incorrect task context in smack_msg_queue_msgrcv\\n\\nThe smack_msg_queue_msgrcv() function incorrectly checks\\nthe permissions of the \u0027current\u0027 task instead of the\\n\u0027target\u0027 task.\\n\\nIn the msgsnd() syscall path, if a receiver is already waiting,\\nthe pipelined_send() optimization is used to push the message\\ndirectly to the receiver task:\\n\\n ipc/msg.c`pipelined_send():\\n ` smp_store_release(\u0026msr-\u003er_msg, msg)\\n\\nIn this case, the \u0027sender\u0027 (current) task performs the check\\non behalf of the \u0027receiver\u0027 task (msr-\u003er_tsk, passed as the\\n\u0027target\u0027 parameter):\\n\\n ipc/msg.c`pipelined_send():\\n ` security_msg_queue_msgrcv(,, target := msr-\u003er_tsk,,)\\n\\nHowever, smack_msg_queue_msgrcv() ignores the \u0027target\u0027 and\\nchecks \u0027current\u0027:\\n\\n smack_msg_queue_msgrcv(\u2026)\\n ` smk_curacc_msq(isp, MAY_READWRITE); // current task\\n\\n\u0027current\u0027 MAY satisfy smack_msg_queue_msgrcv r/w requirement,\\nbut \u0027target\u0027 (the receiver task) might NOT;\\nas a result, an unauthorized receiver gets the message,\\nviolating MAC policy.\\n\\nTest:\\n1) create a sysv message queue with label \u201cfoo\u201d\\n2) echo \\\"bar foo r\\\" \u003e/smack/load2\\n3) msgrcv(,,,0,MSG_NOERROR) in \\\"bar\\\"-labeled task.\\n The task is waiting for the messages ...\\n4) msgsnd() from a \\\"foo\\\"-labeled task:\\n\\\"bar\\\"-labeled task gets the message.\\n\\nThis patch fixes the issue by checking permission on the\\n\u0027target\u0027 task instead of \u0027current\u0027.\\n\\n(2008-02-04, Casey Schaufler)\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"security/smack/smack_lsm.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"e114e473771c848c3cfec05f0123e70f1cdbdc99\",\"lessThan\":\"4e49f997ef0c569e09b42aab6bd38c7c54ea095d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"e114e473771c848c3cfec05f0123e70f1cdbdc99\",\"lessThan\":\"dbece6c2f80b0470d8d99d7a016827dce99ed6e3\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"e114e473771c848c3cfec05f0123e70f1cdbdc99\",\"lessThan\":\"7be4bd21c50afa83c93799b0f16cf5bfa493194e\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"e114e473771c848c3cfec05f0123e70f1cdbdc99\",\"lessThan\":\"ec47f4177046dfaaf1cebb15f4d2e7b543475daf\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"e114e473771c848c3cfec05f0123e70f1cdbdc99\",\"lessThan\":\"e35dc5a4ed6d1e536382d80c685187511ff248a1\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"e114e473771c848c3cfec05f0123e70f1cdbdc99\",\"lessThan\":\"c2ab27c2e11591524b1378c24ad18882a425d1fa\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"e114e473771c848c3cfec05f0123e70f1cdbdc99\",\"lessThan\":\"d02c55e3ea82e41ea2c2026e08201e5daa4d0cfe\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"e114e473771c848c3cfec05f0123e70f1cdbdc99\",\"lessThan\":\"fba3d32825f4bbc8e20f0cdc3b14df57965b8fe5\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"security/smack/smack_lsm.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.25\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.25\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.270\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.221\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.188\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.157\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.110\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.52\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2.6\",\"lessThanOrEqual\":\"7.2.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.3-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/4e49f997ef0c569e09b42aab6bd38c7c54ea095d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7be4bd21c50afa83c93799b0f16cf5bfa493194e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c2ab27c2e11591524b1378c24ad18882a425d1fa\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d02c55e3ea82e41ea2c2026e08201e5daa4d0cfe\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/dbece6c2f80b0470d8d99d7a016827dce99ed6e3\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/e35dc5a4ed6d1e536382d80c685187511ff248a1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ec47f4177046dfaaf1cebb15f4d2e7b543475daf\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fba3d32825f4bbc8e20f0cdc3b14df57965b8fe5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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