mirror of
https://github.com/fkie-cad/nvd-json-data-feeds.git
synced 2025-06-01 03:01:36 +00:00
29 lines
2.6 KiB
JSON
29 lines
2.6 KiB
JSON
|
{
|
||
|
|
"id": "CVE-2024-39486",
|
||
|
|
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
|
||
|
|
"published": "2024-07-06T10:15:03.393",
|
||
|
|
"lastModified": "2024-07-06T10:15:03.393",
|
||
|
|
"vulnStatus": "Received",
|
||
|
|
"cveTags": [],
|
||
|
|
"descriptions": [
|
||
|
|
{
|
||
|
|
"lang": "en",
|
||
|
|
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/drm_file: Fix pid refcounting race\n\n\nfilp->pid is supposed to be a refcounted pointer; however, before this\npatch, drm_file_update_pid() only increments the refcount of a struct\npid after storing a pointer to it in filp->pid and dropping the\ndev->filelist_mutex, making the following race possible:\n\nprocess A process B\n========= =========\n begin drm_file_update_pid\n mutex_lock(&dev->filelist_mutex)\n rcu_replace_pointer(filp->pid, <pid B>, 1)\n mutex_unlock(&dev->filelist_mutex)\nbegin drm_file_update_pid\nmutex_lock(&dev->filelist_mutex)\nrcu_replace_pointer(filp->pid, <pid A>, 1)\nmutex_unlock(&dev->filelist_mutex)\nget_pid(<pid A>)\nsynchronize_rcu()\nput_pid(<pid B>) *** pid B reaches refcount 0 and is freed here ***\n get_pid(<pid B>) *** UAF ***\n synchronize_rcu()\n put_pid(<pid A>)\n\nAs far as I know, this race can only occur with CONFIG_PREEMPT_RCU=y\nbecause it requires RCU to detect a quiescent state in code that is not\nexplicitly calling into the scheduler.\n\nThis race leads to use-after-free of a \"struct pid\".\nIt is probably somewhat hard to hit because process A has to pass\nthrough a synchronize_rcu() operation while process B is between\nmutex_unlock() and get_pid().\n\nFix it by ensuring that by the time a pointer to the current task's pid\nis stored in the file, an extra reference to the pid has been taken.\n\nThis fix also removes the condition for synchronize_rcu(); I think\nthat optimization is unnecessary complexity, since in that case we\nwould usually have bailed out on the lockless check above."
|
||
|
|
}
|
||
|
|
],
|
||
|
|
"metrics": {},
|
||
|
|
"references": [
|
||
|
|
{
|
||
|
|
"url": "https://git.kernel.org/stable/c/0acce2a5c619ef1abdee783d7fea5eac78ce4844",
|
||
|
|
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
|
||
|
|
},
|
||
|
|
{
|
||
|
|
"url": "https://git.kernel.org/stable/c/16682588ead4a593cf1aebb33b36df4d1e9e4ffa",
|
||
|
|
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
|
||
|
|
},
|
||
|
|
{
|
||
|
|
"url": "https://git.kernel.org/stable/c/4f2a129b33a2054e62273edd5a051c34c08d96e9",
|
||
|
|
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
|
||
|
|
}
|
||
|
|
]
|
||
|
|
}
|