CVE-2026-98314
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: set timer->private_data before registering the PCM timer snd_pcm_timer_init() calls snd_device_register() to link the new struct snd_timer into the global timer list while it still carries hw.c_resolution = snd_pcm_timer_resolution (and hw.start/hw.stop), and only afterwards sets timer->private_data = substream. Once the timer is on the list under register_mutex, a concurrent reader can already reach it through the same mutex and invoke these callbacks. /proc/asound/timers does this via c_resolution(), and snd_timer_open()+snd_timer_start() reach start()/stop() the same way. All three dereference timer->private_data, which for this brief window is NULL, giving a NULL-pointer dereference: substream = timer->private_data; return substream->runtime ? ... // substream is NULL Move the private_data/private_free assignment before snd_device_register() so the timer is never visible on the list without its private_data set. On the snd_device_register() failure path, private_free() (snd_pcm_timer_free()) can now run, but it only does substream->timer = NULL, which is already NULL at that point since substream->timer is set to the new timer just once, after a successful registration -- so the failure path stays safe.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-06 09:18:23.033000
Last modified
2026-10-19 10:18:33.520000
View original CVE JSON
{
"id": "CVE-2026-98314",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-06T09:18:23.033",
"lastModified": "2026-10-19T10:18:33.520",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: pcm: set timer->private_data before registering the PCM timer\n\nsnd_pcm_timer_init() calls snd_device_register() to link the new\nstruct snd_timer into the global timer list while it still carries\nhw.c_resolution = snd_pcm_timer_resolution (and hw.start/hw.stop),\nand only afterwards sets timer->private_data = substream.\n\nOnce the timer is on the list under register_mutex, a concurrent\nreader can already reach it through the same mutex and invoke these\ncallbacks. /proc/asound/timers does this via c_resolution(), and\nsnd_timer_open()+snd_timer_start() reach start()/stop() the same way.\nAll three dereference timer->private_data, which for this brief\nwindow is NULL, giving a NULL-pointer dereference:\n\n substream = timer->private_data;\n return substream->runtime ? ... // substream is NULL\n\nMove the private_data/private_free assignment before\nsnd_device_register() so the timer is never visible on the list\nwithout its private_data set. On the snd_device_register() failure\npath, private_free() (snd_pcm_timer_free()) can now run, but it only\ndoes substream->timer = NULL, which is already NULL at that point\nsince substream->timer is set to the new timer just once, after a\nsuccessful registration -- so the failure path stays safe."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"sound/core/pcm_timer.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
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"lessThan": "27f167e117eca310661fbcbacb352ea08face067",
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],
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{
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},
{
"version": "0",
"lessThan": "2.6.12",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.271",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.222",
"lessThanOrEqual": "5.15.*",
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},
{
"version": "6.1.189",
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},
{
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},
{
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},
{
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},
{
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},
{
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"versionType": "original_commit_for_fix",
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}
]
}
]
}
],
"metrics": {},
"references": [
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