ghsa-3h59-8483-h44f
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
ALSA: Fix deadlocks with kctl removals at disconnection
In snd_card_disconnect(), we set card->shutdown flag at the beginning, call callbacks and do sync for card->power_ref_sleep waiters at the end. The callback may delete a kctl element, and this can lead to a deadlock when the device was in the suspended state. Namely:
-
A process waits for the power up at snd_power_ref_and_wait() in snd_ctl_info() or read/write() inside card->controls_rwsem.
-
The system gets disconnected meanwhile, and the driver tries to delete a kctl via snd_ctl_remove*(); it tries to take card->controls_rwsem again, but this is already locked by the above. Since the sleeper isn't woken up, this deadlocks.
An easy fix is to wake up sleepers before processing the driver disconnect callbacks but right after setting the card->shutdown flag. Then all sleepers will abort immediately, and the code flows again.
So, basically this patch moves the wait_event() call at the right timing. While we're at it, just to be sure, call wait_event_all() instead of wait_event(), although we don't use exclusive events on this queue for now.
{
"affected": [],
"aliases": [
"CVE-2024-38600"
],
"database_specific": {
"cwe_ids": [
"CWE-667"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-06-19T14:15:19Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: Fix deadlocks with kctl removals at disconnection\n\nIn snd_card_disconnect(), we set card-\u003eshutdown flag at the beginning,\ncall callbacks and do sync for card-\u003epower_ref_sleep waiters at the\nend. The callback may delete a kctl element, and this can lead to a\ndeadlock when the device was in the suspended state. Namely:\n\n* A process waits for the power up at snd_power_ref_and_wait() in\n snd_ctl_info() or read/write() inside card-\u003econtrols_rwsem.\n\n* The system gets disconnected meanwhile, and the driver tries to\n delete a kctl via snd_ctl_remove*(); it tries to take\n card-\u003econtrols_rwsem again, but this is already locked by the\n above. Since the sleeper isn\u0027t woken up, this deadlocks.\n\nAn easy fix is to wake up sleepers before processing the driver\ndisconnect callbacks but right after setting the card-\u003eshutdown flag.\nThen all sleepers will abort immediately, and the code flows again.\n\nSo, basically this patch moves the wait_event() call at the right\ntiming. While we\u0027re at it, just to be sure, call wait_event_all()\ninstead of wait_event(), although we don\u0027t use exclusive events on\nthis queue for now.",
"id": "GHSA-3h59-8483-h44f",
"modified": "2024-08-27T18:31:35Z",
"published": "2024-06-19T15:30:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-38600"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2f103287ef7960854808930499d1181bd0145d68"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6b55e879e7bd023a03888fc6c8339edf82f576f4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/87988a534d8e12f2e6fc01fe63e6c1925dc5307c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/88ce3fe255d58a93624b467af036dc3519f309c7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c2fb439f4f1425a961d20bec818fed2c2d9ef70a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ff80185e7b7b547a0911fcfc8aefc61c3e8304d7"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}