FKIE_CVE-2026-31576
Vulnerability from fkie_nvd - Published: 2026-04-24 15:16 - Updated: 2026-04-24 17:51
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
media: hackrf: fix to not free memory after the device is registered in hackrf_probe()
In hackrf driver, the following race condition occurs:
```
CPU0 CPU1
hackrf_probe()
kzalloc(); // alloc hackrf_dev
....
v4l2_device_register();
....
fd = sys_open("/path/to/dev"); // open hackrf fd
....
v4l2_device_unregister();
....
kfree(); // free hackrf_dev
....
sys_ioctl(fd, ...);
v4l2_ioctl();
video_is_registered() // UAF!!
....
sys_close(fd);
v4l2_release() // UAF!!
hackrf_video_release()
kfree(); // DFB!!
```
When a V4L2 or video device is unregistered, the device node is removed so
new open() calls are blocked.
However, file descriptors that are already open-and any in-flight I/O-do
not terminate immediately; they remain valid until the last reference is
dropped and the driver's release() is invoked.
Therefore, freeing device memory on the error path after hackrf_probe()
has registered dev it will lead to a race to use-after-free vuln, since
those already-open handles haven't been released yet.
And since release() free memory too, race to use-after-free and
double-free vuln occur.
To prevent this, if device is registered from probe(), it should be
modified to free memory only through release() rather than calling
kfree() directly.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: hackrf: fix to not free memory after the device is registered in hackrf_probe()\n\nIn hackrf driver, the following race condition occurs:\n```\n\t\tCPU0\t\t\t\t\t\tCPU1\nhackrf_probe()\n kzalloc(); // alloc hackrf_dev\n ....\n v4l2_device_register();\n ....\n\t\t\t\t\t\tfd = sys_open(\"/path/to/dev\"); // open hackrf fd\n\t\t\t\t\t\t....\n v4l2_device_unregister();\n ....\n kfree(); // free hackrf_dev\n ....\n\t\t\t\t\t\tsys_ioctl(fd, ...);\n\t\t\t\t\t\t v4l2_ioctl();\n\t\t\t\t\t\t video_is_registered() // UAF!!\n\t\t\t\t\t\t....\n\t\t\t\t\t\tsys_close(fd);\n\t\t\t\t\t\t v4l2_release() // UAF!!\n\t\t\t\t\t\t hackrf_video_release()\n\t\t\t\t\t\t kfree(); // DFB!!\n```\n\nWhen a V4L2 or video device is unregistered, the device node is removed so\nnew open() calls are blocked.\n\nHowever, file descriptors that are already open-and any in-flight I/O-do\nnot terminate immediately; they remain valid until the last reference is\ndropped and the driver\u0027s release() is invoked.\n\nTherefore, freeing device memory on the error path after hackrf_probe()\nhas registered dev it will lead to a race to use-after-free vuln, since\nthose already-open handles haven\u0027t been released yet.\n\nAnd since release() free memory too, race to use-after-free and\ndouble-free vuln occur.\n\nTo prevent this, if device is registered from probe(), it should be\nmodified to free memory only through release() rather than calling\nkfree() directly."
}
],
"id": "CVE-2026-31576",
"lastModified": "2026-04-24T17:51:40.810",
"metrics": {},
"published": "2026-04-24T15:16:32.230",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/07e9e674b6146b1f6fc41b1f54b8968bf2802824"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2145c71a8044362e82e9923f001ba2aeb771b848"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/98a0a81ce78020c2522e0046f49d200de9778cb9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/fcd1d70792a35c8a97414fe429f48311e41269c2"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Sightings
| Author | Source | Type | Date |
|---|
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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