CVE-2026-98116
In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: Serialize PCM mmap with buffer reallocation to fix page UAF
snd_pcm_hw_params() and snd_pcm_hw_free() guard buffer reallocation with an mmap_count check performed under the PCM stream lock, but the lock is released long before the buffer is actually freed: snd_pcm_sync_stop(), constraint refinement and do_free_pages() all happen in between. snd_pcm_mmap_data(), on the other hand, takes no lock at all: it validates against the old buffer's state and dma_bytes, remaps its pages into the VMA, and only then increments mmap_count.
Leer descripción completaMostrar menos
A concurrent mmap() can therefore slip in between the check and the free. remap_pfn_range() installs writable PTEs for the old buffer's pages without taking page references, and the subsequent do_free_pages() returns those pages to the page allocator while the VMA still maps them. This leaves a stale, writable mapping of freed pages: a page-level use-after-free that can be leveraged for local privilege escalation.
Make snd_pcm_mmap_data() participate in the buffer-access scheme introduced for hw_params/hw_free: acquire runtime->buffer_accessing before validating and remapping, and release it afterwards. Buffer reallocation already fails with -EBUSY while accessors are active, and the mmap side now fails with -EBUSY while a reallocation is in progress, so the validate/remap sequence and the check/free sequence can no longer interleave.
A reproducer that turns this race into a stale writable mapping of the freed DMA buffer pages is available on request.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.13%
- Percentil entre todas las CVEs puntuadas: 2
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation95 % - Impacto principal
T1548Abuse Elevation Control Mechanismprivilege escalation90 % - Impacto secundario
T1005Data from Local Systemcollection75 %
UAF de páginas en kernel con acceso local; permite escalada de privilegios mediante MMU race condition en ALSA PCM buffer reallocation con permisos locales (AV:L, PR:L).
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
- https://git.kernel.org/stable/c/8c1882dfee8f404d118020664b73eb4592172226
- https://git.kernel.org/stable/c/9857a75714bb5df4781e4d8b1a1753b1e17bf07a
- https://git.kernel.org/stable/c/9b110a9dcecc59516c77cb3c0caf1f492f75df2d
- https://git.kernel.org/stable/c/cbadf2575d25e7dcc0d4da2717817ae569fbc99b
- https://git.kernel.org/stable/c/cbc7ec97601d09b74e05e44470fa6b0bcdabf3f5
- https://git.kernel.org/stable/c/e6cdd2a0470d64073349a970dc1691433804b271
- https://git.kernel.org/stable/c/fd137bf8149bc6460f9b7b1fc292025da04cb9ee
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-98116",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
},
"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": "33061d0fba51d2bf70a2ef9645f703c33fe8e438",
"lessThan": "e6cdd2a0470d64073349a970dc1691433804b271",
"versionType": "git"
},
{
"status": "affected",
"version": "92ee3c60ec9fe64404dc035e7c41277d74aa26cb",
"lessThan": "9857a75714bb5df4781e4d8b1a1753b1e17bf07a",
"versionType": "git"
},
{
"status": "affected",
"version": "92ee3c60ec9fe64404dc035e7c41277d74aa26cb",
"lessThan": "cbadf2575d25e7dcc0d4da2717817ae569fbc99b",
"versionType": "git"
},
{
"status": "affected",
"version": "92ee3c60ec9fe64404dc035e7c41277d74aa26cb",
"lessThan": "cbc7ec97601d09b74e05e44470fa6b0bcdabf3f5",
"versionType": "git"
},
{
"status": "affected",
"version": "92ee3c60ec9fe64404dc035e7c41277d74aa26cb",
"lessThan": "fd137bf8149bc6460f9b7b1fc292025da04cb9ee",
"versionType": "git"
},
{
"status": "affected",
"version": "92ee3c60ec9fe64404dc035e7c41277d74aa26cb",
"lessThan": "8c1882dfee8f404d118020664b73eb4592172226",
"versionType": "git"
},
{
"status": "affected",
"version": "92ee3c60ec9fe64404dc035e7c41277d74aa26cb",
"lessThan": "9b110a9dcecc59516c77cb3c0caf1f492f75df2d",
"versionType": "git"
},
{
"status": "affected",
"version": "a42aa926843acca96c0dfbde2e835b8137f2f092",
"versionType": "git"
},
{
"status": "affected",
"version": "9cb6c40a6ebe4a0cfc9d6a181958211682cffea9",
"versionType": "git"
},
{
"status": "affected",
"version": "fbeb492694ce0441053de57699e1e2b7bc148a69",
"versionType": "git"
},
{
"status": "affected",
"version": "0f6947f5f5208f6ebd4d76a82a4757e2839a23f8",
"versionType": "git"
},
{
"status": "affected",
"version": "0090c13cbbdffd7da079ac56f80373a9a1be0bf8",
"versionType": "git"
},
{
"status": "affected",
"version": "1bbf82d9f961414d6c76a08f7f843ea068e0ab7b",
"versionType": "git"
},
{
"status": "affected",
"version": "5.15.32",
"lessThan": "5.15.222",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.14.279",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.19.243",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.4.193",
"lessThan": "5.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.10.109",
"lessThan": "5.11",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.16.18",
"lessThan": "5.17",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.17.1",
"lessThan": "5.18",
"versionType": "semver"
}
],
"programFiles": [
"sound/core/pcm_native.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"sound/core/pcm_native.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-25T11:17:42.780",
"references": [
{
"url": "https://git.kernel.org/stable/c/8c1882dfee8f404d118020664b73eb4592172226",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9857a75714bb5df4781e4d8b1a1753b1e17bf07a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9b110a9dcecc59516c77cb3c0caf1f492f75df2d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/cbadf2575d25e7dcc0d4da2717817ae569fbc99b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/cbc7ec97601d09b74e05e44470fa6b0bcdabf3f5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e6cdd2a0470d64073349a970dc1691433804b271",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fd137bf8149bc6460f9b7b1fc292025da04cb9ee",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Undergoing Analysis",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: pcm: Serialize PCM mmap with buffer reallocation to fix page UAF\n\nsnd_pcm_hw_params() and snd_pcm_hw_free() guard buffer reallocation\nwith an mmap_count check performed under the PCM stream lock, but the\nlock is released long before the buffer is actually freed:\nsnd_pcm_sync_stop(), constraint refinement and do_free_pages() all\nhappen in between. snd_pcm_mmap_data(), on the other hand, takes no\nlock at all: it validates against the old buffer's state and\ndma_bytes, remaps its pages into the VMA, and only then increments\nmmap_count.\n\nA concurrent mmap() can therefore slip in between the check and the\nfree. remap_pfn_range() installs writable PTEs for the old buffer's\npages without taking page references, and the subsequent\ndo_free_pages() returns those pages to the page allocator while the\nVMA still maps them. This leaves a stale, writable mapping of freed\npages: a page-level use-after-free that can be leveraged for local\nprivilege escalation.\n\nMake snd_pcm_mmap_data() participate in the buffer-access scheme\nintroduced for hw_params/hw_free: acquire runtime->buffer_accessing\nbefore validating and remapping, and release it afterwards. Buffer\nreallocation already fails with -EBUSY while accessors are active,\nand the mmap side now fails with -EBUSY while a reallocation is in\nprogress, so the validate/remap sequence and the check/free sequence\ncan no longer interleave.\n\nA reproducer that turns this race into a stale writable mapping of\nthe freed DMA buffer pages is available on request."
}
],
"lastModified": "2026-10-03T11:18:33.517",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}