FKIE_CVE-2026-23327
Vulnerability from fkie_nvd - Published: 2026-03-25 11:16 - Updated: 2026-04-23 21:11
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
cxl/mbox: validate payload size before accessing contents in cxl_payload_from_user_allowed()
cxl_payload_from_user_allowed() casts and dereferences the input
payload without first verifying its size. When a raw mailbox command
is sent with an undersized payload (ie: 1 byte for CXL_MBOX_OP_CLEAR_LOG,
which expects a 16-byte UUID), uuid_equal() reads past the allocated buffer,
triggering a KASAN splat:
BUG: KASAN: slab-out-of-bounds in memcmp+0x176/0x1d0 lib/string.c:683
Read of size 8 at addr ffff88810130f5c0 by task syz.1.62/2258
CPU: 2 UID: 0 PID: 2258 Comm: syz.1.62 Not tainted 6.19.0-dirty #3 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xab/0xe0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xce/0x650 mm/kasan/report.c:482
kasan_report+0xce/0x100 mm/kasan/report.c:595
memcmp+0x176/0x1d0 lib/string.c:683
uuid_equal include/linux/uuid.h:73 [inline]
cxl_payload_from_user_allowed drivers/cxl/core/mbox.c:345 [inline]
cxl_mbox_cmd_ctor drivers/cxl/core/mbox.c:368 [inline]
cxl_validate_cmd_from_user drivers/cxl/core/mbox.c:522 [inline]
cxl_send_cmd+0x9c0/0xb50 drivers/cxl/core/mbox.c:643
__cxl_memdev_ioctl drivers/cxl/core/memdev.c:698 [inline]
cxl_memdev_ioctl+0x14f/0x190 drivers/cxl/core/memdev.c:713
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa8/0x330 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdaf331ba79
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdaf1d77038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdaf3585fa0 RCX: 00007fdaf331ba79
RDX: 00002000000001c0 RSI: 00000000c030ce02 RDI: 0000000000000003
RBP: 00007fdaf33749df R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdaf3586038 R14: 00007fdaf3585fa0 R15: 00007ffced2af768
</TASK>
Add 'in_size' parameter to cxl_payload_from_user_allowed() and validate
the payload is large enough.
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | 5.19 | |
| linux | linux_kernel | 7.0 | |
| linux | linux_kernel | 7.0 | |
| linux | linux_kernel | 7.0 | |
| linux | linux_kernel | 7.0 | |
| linux | linux_kernel | 7.0 | |
| linux | linux_kernel | 7.0 | |
| linux | linux_kernel | 7.0 |
{
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "74C0D01A-385D-4859-8FCC-93ACC7B4B847",
"versionEndExcluding": "6.19.7",
"versionStartIncluding": "5.19.1",
"vulnerable": true
},
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"vulnerable": true
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"matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2",
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"vulnerable": true
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"vulnerable": true
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"matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138",
"vulnerable": true
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"negate": false,
"operator": "OR"
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],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/mbox: validate payload size before accessing contents in cxl_payload_from_user_allowed()\n\ncxl_payload_from_user_allowed() casts and dereferences the input\npayload without first verifying its size. When a raw mailbox command\nis sent with an undersized payload (ie: 1 byte for CXL_MBOX_OP_CLEAR_LOG,\nwhich expects a 16-byte UUID), uuid_equal() reads past the allocated buffer,\ntriggering a KASAN splat:\n\nBUG: KASAN: slab-out-of-bounds in memcmp+0x176/0x1d0 lib/string.c:683\nRead of size 8 at addr ffff88810130f5c0 by task syz.1.62/2258\n\nCPU: 2 UID: 0 PID: 2258 Comm: syz.1.62 Not tainted 6.19.0-dirty #3 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0xab/0xe0 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xce/0x650 mm/kasan/report.c:482\n kasan_report+0xce/0x100 mm/kasan/report.c:595\n memcmp+0x176/0x1d0 lib/string.c:683\n uuid_equal include/linux/uuid.h:73 [inline]\n cxl_payload_from_user_allowed drivers/cxl/core/mbox.c:345 [inline]\n cxl_mbox_cmd_ctor drivers/cxl/core/mbox.c:368 [inline]\n cxl_validate_cmd_from_user drivers/cxl/core/mbox.c:522 [inline]\n cxl_send_cmd+0x9c0/0xb50 drivers/cxl/core/mbox.c:643\n __cxl_memdev_ioctl drivers/cxl/core/memdev.c:698 [inline]\n cxl_memdev_ioctl+0x14f/0x190 drivers/cxl/core/memdev.c:713\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:597 [inline]\n __se_sys_ioctl fs/ioctl.c:583 [inline]\n __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xa8/0x330 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fdaf331ba79\nCode: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 \u003c48\u003e 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007fdaf1d77038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\nRAX: ffffffffffffffda RBX: 00007fdaf3585fa0 RCX: 00007fdaf331ba79\nRDX: 00002000000001c0 RSI: 00000000c030ce02 RDI: 0000000000000003\nRBP: 00007fdaf33749df R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007fdaf3586038 R14: 00007fdaf3585fa0 R15: 00007ffced2af768\n \u003c/TASK\u003e\n\nAdd \u0027in_size\u0027 parameter to cxl_payload_from_user_allowed() and validate\nthe payload is large enough."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\ncxl/mbox: validar el tama\u00f1o de la carga \u00fatil antes de acceder a los contenidos en cxl_payload_from_user_allowed()\n\ncxl_payload_from_user_allowed() convierte y desreferencia la carga \u00fatil de entrada sin verificar primero su tama\u00f1o. Cuando se env\u00eda un comando de buz\u00f3n sin procesar con una carga \u00fatil de tama\u00f1o insuficiente (es decir: 1 byte para CXL_MBOX_OP_CLEAR_LOG, que espera un UUID de 16 bytes), uuid_equal() lee m\u00e1s all\u00e1 del b\u00fafer asignado, lo que activa un KASAN splat:\n\nBUG: KASAN: slab-out-of-bounds en memcmp+0x176/0x1d0 lib/string.c:683\nLectura de tama\u00f1o 8 en la direcci\u00f3n ffff88810130f5c0 por la tarea syz.1.62/2258\n\nCPU: 2 UID: 0 PID: 2258 Comm: syz.1.62 No contaminado 6.19.0-dirty #3 PREEMPT(voluntary)\nNombre del hardware: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014\nTraza de llamadas:\n \n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0xab/0xe0 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xce/0x650 mm/kasan/report.c:482\n kasan_report+0xce/0x100 mm/kasan/report.c:595\n memcmp+0x176/0x1d0 lib/string.c:683\n uuid_equal include/linux/uuid.h:73 [inline]\n cxl_payload_from_user_allowed drivers/cxl/core/mbox.c:345 [inline]\n cxl_mbox_cmd_ctor drivers/cxl/core/mbox.c:368 [inline]\n cxl_validate_cmd_from_user drivers/cxl/core/mbox.c:522 [inline]\n cxl_send_cmd+0x9c0/0xb50 drivers/cxl/core/mbox.c:643\n __cxl_memdev_ioctl drivers/cxl/core/memdev.c:698 [inline]\n cxl_memdev_ioctl+0x14f/0x190 drivers/cxl/core/memdev.c:713\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:597 [inline]\n __se_sys_ioctl fs/ioctl.c:583 [inline]\n __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xa8/0x330 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fdaf331ba79\nCode: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 \u0026lt;48\u0026gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007fdaf1d77038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\nRAX: ffffffffffffffda RBX: 00007fdaf3585fa0 RCX: 00007fdaf331ba79\nRDX: 00002000000001c0 RSI: 00000000c030ce02 RDI: 0000000000000003\nRBP: 00007fdaf33749df R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007fdaf3586038 R14: 00007fdaf3585fa0 R15: 00007ffced2af768\n \n\nA\u00f1adir el par\u00e1metro \u0027in_size\u0027 a cxl_payload_from_user_allowed() y validar que la carga \u00fatil sea lo suficientemente grande."
}
],
"id": "CVE-2026-23327",
"lastModified": "2026-04-23T21:11:13.010",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.1,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.2,
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"published": "2026-03-25T11:16:29.837",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/60b5d1f68338aff2c5af0113f04aefa7169c50c2"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/7c8a7b7f063b7e7ae9bba4cbaa14a5d2fe3a55e1"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-125"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
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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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