{"cve":"CVE-2022-49300","nvd":{"published":"2025-02-26T07:01:06.830","modified":"2026-06-17T05:17:38.703","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: fix race between nbd_alloc_config() and module removal\n\nWhen nbd module is being removing, nbd_alloc_config() may be\ncalled concurrently by nbd_genl_connect(), although try_module_get()\nwill return false, but nbd_alloc_config() doesn't handle it.\n\nThe race may lead to the leak of nbd_config and its related\nresources (e.g, recv_workq) and oops in nbd_read_stat() due\nto the unload of nbd module as shown below:\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000040\n  Oops: 0000 [#1] SMP PTI\n  CPU: 5 PID: 13840 Comm: kworker/u17:33 Not tainted 5.14.0+ #1\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)\n  Workqueue: knbd16-recv recv_work [nbd]\n  RIP: 0010:nbd_read_stat.cold+0x130/0x1a4 [nbd]\n  Call Trace:\n   recv_work+0x3b/0xb0 [nbd]\n   process_one_work+0x1ed/0x390\n   worker_thread+0x4a/0x3d0\n   kthread+0x12a/0x150\n   ret_from_fork+0x22/0x30\n\nFixing it by checking the return value of try_module_get()\nin nbd_alloc_config(). As nbd_alloc_config() may return ERR_PTR(-ENODEV),\nassign nbd->config only when nbd_alloc_config() succeeds to ensure\nthe value of nbd->config is binary (valid or NULL).\n\nAlso adding a debug message to check the reference counter\nof nbd_config during module removal.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","score":4.7},"cwes":["CWE-362","CWE-476"],"references":["https://git.kernel.org/stable/c/122e4adaff2439f1cc18cc7e931980fa7560df5c","https://git.kernel.org/stable/c/165cf2e0019fa6cedc75b456490c41494c34abb4","https://git.kernel.org/stable/c/2573f2375b64280be977431701ed5d33b75b9ad0","https://git.kernel.org/stable/c/2888fa41985f93ed0a6837cfbb06bcbfd7fa2314","https://git.kernel.org/stable/c/71c142f910da44421213ade601bcbd23ceae19fa"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:59:48.811064707+00:00"},"epss":{"cve":"CVE-2022-49300","score":0.00192,"percentile":0.08923,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}