CVE-2025-39979
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: fs, fix UAF in flow counter release
Fix a kernel trace [1] caused by releasing an HWS action of a local flow counter in mlx5_cmd_hws_delete_fte(), where the HWS action refcount and mutex were not initialized and the counter struct could already be freed when deleting the rule.
Fix it by adding the missing initializations and adding refcount for the local flow counter struct.
Detalles técnicos trazas, registros y código del informe original
[1] Kernel log: Call Trace: <TASK> dump_stack_lvl+0x34/0x48 mlx5_fs_put_hws_action.part.0.cold+0x21/0x94 [mlx5_core] mlx5_fc_put_hws_action+0x96/0xad [mlx5_core] mlx5_fs_destroy_fs_actions+0x8b/0x152 [mlx5_core] mlx5_cmd_hws_delete_fte+0x5a/0xa0 [mlx5_core] del_hw_fte+0x1ce/0x260 [mlx5_core] mlx5_del_flow_rules+0x12d/0x240 [mlx5_core] ? ttwu_queue_wakelist+0xf4/0x110 mlx5_ib_destroy_flow+0x103/0x1b0 [mlx5_ib] uverbs_free_flow+0x20/0x50 [ib_uverbs] destroy_hw_idr_uobject+0x1b/0x50 [ib_uverbs] uverbs_destroy_uobject+0x34/0x1a0 [ib_uverbs] uobj_destroy+0x3c/0x80 [ib_uverbs] ib_uverbs_run_method+0x23e/0x360 [ib_uverbs] ? uverbs_finalize_object+0x60/0x60 [ib_uverbs] ib_uverbs_cmd_verbs+0x14f/0x2c0 [ib_uverbs] ? do_tty_write+0x1a9/0x270 ? file_tty_write.constprop.0+0x98/0xc0 ? new_sync_write+0xfc/0x190 ib_uverbs_ioctl+0xd7/0x160 [ib_uverbs] __x64_sys_ioctl+0x87/0xc0 do_syscall_64+0x59/0x90
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: 0.14%
- Percentil entre todas las CVEs puntuadas: 3
- Fecha de la puntuación: 6/10/2026
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 escalation85 % - Impacto principal
T1499.004Application or System Exploitationimpact80 %
UAF en kernel con PR:L y AV:L permite escalada de privilegios local. El fallo de inicialización de refcount y mutex causa pánico del kernel (DoS) y potencial corrupción de memoria.
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
JSON original (NVD)
Mostrar
{
"id": "CVE-2025-39979",
"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": "b581f4266928d3b5d1bbe711e39623d9a1696091",
"lessThan": "3c77f6d244188c3fb11f6aec40bbfe884f1803b5",
"versionType": "git"
},
{
"status": "affected",
"version": "b581f4266928d3b5d1bbe711e39623d9a1696091",
"lessThan": "6043819e707cefb1c9e59d6e431dcfa735c4f975",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/ethernet/mellanox/mlx5/core/fs_core.c",
"drivers/net/ethernet/mellanox/mlx5/core/fs_core.h",
"drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c",
"drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws_pools.c",
"include/linux/mlx5/fs.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.14"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.14",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.16.10",
"versionType": "semver",
"lessThanOrEqual": "6.16.*"
},
{
"status": "unaffected",
"version": "6.17",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/ethernet/mellanox/mlx5/core/fs_core.c",
"drivers/net/ethernet/mellanox/mlx5/core/fs_core.h",
"drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c",
"drivers/net/ethernet/mellanox/mlx5/core/steering/hws/fs_hws_pools.c",
"include/linux/mlx5/fs.h"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-10-15T08:15:35.767",
"references": [
{
"url": "https://git.kernel.org/stable/c/3c77f6d244188c3fb11f6aec40bbfe884f1803b5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6043819e707cefb1c9e59d6e431dcfa735c4f975",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Deferred",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5: fs, fix UAF in flow counter release\n\nFix a kernel trace [1] caused by releasing an HWS action of a local flow\ncounter in mlx5_cmd_hws_delete_fte(), where the HWS action refcount and\nmutex were not initialized and the counter struct could already be freed\nwhen deleting the rule.\n\nFix it by adding the missing initializations and adding refcount for the\nlocal flow counter struct.\n\n[1] Kernel log:\n Call Trace:\n <TASK>\n dump_stack_lvl+0x34/0x48\n mlx5_fs_put_hws_action.part.0.cold+0x21/0x94 [mlx5_core]\n mlx5_fc_put_hws_action+0x96/0xad [mlx5_core]\n mlx5_fs_destroy_fs_actions+0x8b/0x152 [mlx5_core]\n mlx5_cmd_hws_delete_fte+0x5a/0xa0 [mlx5_core]\n del_hw_fte+0x1ce/0x260 [mlx5_core]\n mlx5_del_flow_rules+0x12d/0x240 [mlx5_core]\n ? ttwu_queue_wakelist+0xf4/0x110\n mlx5_ib_destroy_flow+0x103/0x1b0 [mlx5_ib]\n uverbs_free_flow+0x20/0x50 [ib_uverbs]\n destroy_hw_idr_uobject+0x1b/0x50 [ib_uverbs]\n uverbs_destroy_uobject+0x34/0x1a0 [ib_uverbs]\n uobj_destroy+0x3c/0x80 [ib_uverbs]\n ib_uverbs_run_method+0x23e/0x360 [ib_uverbs]\n ? uverbs_finalize_object+0x60/0x60 [ib_uverbs]\n ib_uverbs_cmd_verbs+0x14f/0x2c0 [ib_uverbs]\n ? do_tty_write+0x1a9/0x270\n ? file_tty_write.constprop.0+0x98/0xc0\n ? new_sync_write+0xfc/0x190\n ib_uverbs_ioctl+0xd7/0x160 [ib_uverbs]\n __x64_sys_ioctl+0x87/0xc0\n do_syscall_64+0x59/0x90"
}
],
"lastModified": "2026-07-30T06:24:03.967",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}