ghsa-9x47-h3pc-w4pg
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
nbd: defer config unlock in nbd_genl_connect
There is one use-after-free warning when running NBD_CMD_CONNECT and NBD_CLEAR_SOCK:
nbd_genl_connect nbd_alloc_and_init_config // config_refs=1 nbd_start_device // config_refs=2 set NBD_RT_HAS_CONFIG_REF open nbd // config_refs=3 recv_work done // config_refs=2 NBD_CLEAR_SOCK // config_refs=1 close nbd // config_refs=0 refcount_inc -> uaf
------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 24 PID: 1014 at lib/refcount.c:25 refcount_warn_saturate+0x12e/0x290 nbd_genl_connect+0x16d0/0x1ab0 genl_family_rcv_msg_doit+0x1f3/0x310 genl_rcv_msg+0x44a/0x790
The issue can be easily reproduced by adding a small delay before refcount_inc(&nbd->config_refs) in nbd_genl_connect():
mutex_unlock(&nbd->config_lock);
if (!ret) {
set_bit(NBD_RT_HAS_CONFIG_REF, &config->runtime_flags);
- printk("before sleep\n");
- mdelay(5 * 1000);
- printk("after sleep\n"); refcount_inc(&nbd->config_refs); nbd_connect_reply(info, nbd->index); }
{
"affected": [],
"aliases": [
"CVE-2025-68366"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-24T11:16:00Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: defer config unlock in nbd_genl_connect\n\nThere is one use-after-free warning when running NBD_CMD_CONNECT and\nNBD_CLEAR_SOCK:\n\nnbd_genl_connect\n nbd_alloc_and_init_config // config_refs=1\n nbd_start_device // config_refs=2\n set NBD_RT_HAS_CONFIG_REF\t\t\topen nbd // config_refs=3\n recv_work done // config_refs=2\n\t\t\t\t\t\tNBD_CLEAR_SOCK // config_refs=1\n\t\t\t\t\t\tclose nbd // config_refs=0\n refcount_inc -\u003e uaf\n\n------------[ cut here ]------------\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 24 PID: 1014 at lib/refcount.c:25 refcount_warn_saturate+0x12e/0x290\n nbd_genl_connect+0x16d0/0x1ab0\n genl_family_rcv_msg_doit+0x1f3/0x310\n genl_rcv_msg+0x44a/0x790\n\nThe issue can be easily reproduced by adding a small delay before\nrefcount_inc(\u0026nbd-\u003econfig_refs) in nbd_genl_connect():\n\n mutex_unlock(\u0026nbd-\u003econfig_lock);\n if (!ret) {\n set_bit(NBD_RT_HAS_CONFIG_REF, \u0026config-\u003eruntime_flags);\n+ printk(\"before sleep\\n\");\n+ mdelay(5 * 1000);\n+ printk(\"after sleep\\n\");\n refcount_inc(\u0026nbd-\u003econfig_refs);\n nbd_connect_reply(info, nbd-\u003eindex);\n }",
"id": "GHSA-9x47-h3pc-w4pg",
"modified": "2025-12-24T12:30:29Z",
"published": "2025-12-24T12:30:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-68366"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1649714b930f9ea6233ce0810ba885999da3b5d4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9a38306643874566d20f7aba7dff9e6f657b51a9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c9b99c948b4fb014812afe7b5ccf2db121d22e46"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c9e805f6a35d1dd189a9345595a5c20e87611942"
}
],
"schema_version": "1.4.0",
"severity": []
}
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