CVE-2025-39765
Estado: AnalizadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
ALSA: timer: fix ida_free call while not allocated
In the snd_utimer_create() function, if the kasprintf() function return NULL, snd_utimer_put_id() will be called, finally use ida_free() to free the unallocated id 0.
The utimer->id should be set properly before the kasprintf() function, ensures the snd_utimer_put_id() function will free the allocated id.
Detalles técnicos trazas, registros y código del informe original
the syzkaller reported the following information: ------------[ cut here ]------------ ida_free called for id=0 which is not allocated. WARNING: CPU: 1 PID: 1286 at lib/idr.c:592 ida_free+0x1fd/0x2f0 lib/idr.c:592 Modules linked in: CPU: 1 UID: 0 PID: 1286 Comm: syz-executor164 Not tainted 6.15.8 #3 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014 RIP: 0010:ida_free+0x1fd/0x2f0 lib/idr.c:592 Code: f8 fc 41 83 fc 3e 76 69 e8 70 b2 f8 (...) RSP: 0018:ffffc900007f79c8 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 1ffff920000fef3b RCX: ffffffff872176a5 RDX: ffff88800369d200 RSI: 0000000000000000 RDI: ffff88800369d200 RBP: 0000000000000000 R08: ffffffff87ba60a5 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f6f1abc1740(0000) GS:ffff8880d76a0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6f1ad7a784 CR3: 000000007a6e2000 CR4: 00000000000006f0 Call Trace: <TASK> snd_utimer_put_id sound/core/timer.c:2043 [inline] [snd_timer] snd_utimer_create+0x59b/0x6a0 sound/core/timer.c:2184 [snd_timer] snd_utimer_ioctl_create sound/core/timer.c:2202 [inline] [snd_timer] __snd_timer_user_ioctl.isra.0+0x724/0x1340 sound/core/timer.c:2287 [snd_timer] snd_timer_user_ioctl+0x75/0xc0 sound/core/timer.c:2298 [snd_timer] vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x198/0x200 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x7b/0x160 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e [...]
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.16%
- Percentil entre todas las CVEs puntuadas: 4
- 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).
Tecnologías afectadas (1)
CWE
- CWE-476
Referencias
JSON original (NVD)
Mostrar
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"source": "nvd@nist.gov",
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"baseScore": 5.5,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
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"version": "6.12.44",
"versionType": "semver",
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"version": "6.16.4",
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"published": "2025-09-11T17:15:40.807",
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"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-476"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: timer: fix ida_free call while not allocated\n\nIn the snd_utimer_create() function, if the kasprintf() function return\nNULL, snd_utimer_put_id() will be called, finally use ida_free()\nto free the unallocated id 0.\n\nthe syzkaller reported the following information:\n ------------[ cut here ]------------\n ida_free called for id=0 which is not allocated.\n WARNING: CPU: 1 PID: 1286 at lib/idr.c:592 ida_free+0x1fd/0x2f0 lib/idr.c:592\n Modules linked in:\n CPU: 1 UID: 0 PID: 1286 Comm: syz-executor164 Not tainted 6.15.8 #3 PREEMPT(lazy)\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014\n RIP: 0010:ida_free+0x1fd/0x2f0 lib/idr.c:592\n Code: f8 fc 41 83 fc 3e 76 69 e8 70 b2 f8 (...)\n RSP: 0018:ffffc900007f79c8 EFLAGS: 00010282\n RAX: 0000000000000000 RBX: 1ffff920000fef3b RCX: ffffffff872176a5\n RDX: ffff88800369d200 RSI: 0000000000000000 RDI: ffff88800369d200\n RBP: 0000000000000000 R08: ffffffff87ba60a5 R09: 0000000000000000\n R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000\n R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000\n FS: 00007f6f1abc1740(0000) GS:ffff8880d76a0000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f6f1ad7a784 CR3: 000000007a6e2000 CR4: 00000000000006f0\n Call Trace:\n <TASK>\n snd_utimer_put_id sound/core/timer.c:2043 [inline] [snd_timer]\n snd_utimer_create+0x59b/0x6a0 sound/core/timer.c:2184 [snd_timer]\n snd_utimer_ioctl_create sound/core/timer.c:2202 [inline] [snd_timer]\n __snd_timer_user_ioctl.isra.0+0x724/0x1340 sound/core/timer.c:2287 [snd_timer]\n snd_timer_user_ioctl+0x75/0xc0 sound/core/timer.c:2298 [snd_timer]\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:907 [inline]\n __se_sys_ioctl fs/ioctl.c:893 [inline]\n __x64_sys_ioctl+0x198/0x200 fs/ioctl.c:893\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x7b/0x160 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n [...]\n\nThe utimer->id should be set properly before the kasprintf() function,\nensures the snd_utimer_put_id() function will free the allocated id."
}
],
"lastModified": "2026-06-17T09:18:26.143",
"configurations": [
{
"nodes": [
{
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}