{"cve":"CVE-2023-54316","nvd":{"published":"2025-12-30T13:16:20.867","modified":"2026-06-17T06:47:12.823","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrefscale: Fix uninitalized use of wait_queue_head_t\n\nRunning the refscale test occasionally crashes the kernel with the\nfollowing error:\n\n[ 8569.952896] BUG: unable to handle page fault for address: ffffffffffffffe8\n[ 8569.952900] #PF: supervisor read access in kernel mode\n[ 8569.952902] #PF: error_code(0x0000) - not-present page\n[ 8569.952904] PGD c4b048067 P4D c4b049067 PUD c4b04b067 PMD 0\n[ 8569.952910] Oops: 0000 [#1] PREEMPT_RT SMP NOPTI\n[ 8569.952916] Hardware name: Dell Inc. PowerEdge R750/0WMWCR, BIOS 1.2.4 05/28/2021\n[ 8569.952917] RIP: 0010:prepare_to_wait_event+0x101/0x190\n  :\n[ 8569.952940] Call Trace:\n[ 8569.952941]  <TASK>\n[ 8569.952944]  ref_scale_reader+0x380/0x4a0 [refscale]\n[ 8569.952959]  kthread+0x10e/0x130\n[ 8569.952966]  ret_from_fork+0x1f/0x30\n[ 8569.952973]  </TASK>\n\nThe likely cause is that init_waitqueue_head() is called after the call to\nthe torture_create_kthread() function that creates the ref_scale_reader\nkthread.  Although this init_waitqueue_head() call will very likely\ncomplete before this kthread is created and starts running, it is\npossible that the calling kthread will be delayed between the calls to\ntorture_create_kthread() and init_waitqueue_head().  In this case, the\nnew kthread will use the waitqueue head before it is properly initialized,\nwhich is not good for the kernel's health and well-being.\n\nThe above crash happened here:\n\n\tstatic inline void __add_wait_queue(...)\n\t{\n\t\t:\n\t\tif (!(wq->flags & WQ_FLAG_PRIORITY)) <=== Crash here\n\nThe offset of flags from list_head entry in wait_queue_entry is\n-0x18. If reader_tasks[i].wq.head.next is NULL as allocated reader_task\nstructure is zero initialized, the instruction will try to access address\n0xffffffffffffffe8, which is exactly the fault address listed above.\n\nThis commit therefore invokes init_waitqueue_head() before creating\nthe kthread.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/066fbd8bc981cf49923bf828b7b4092894df577f","https://git.kernel.org/stable/c/70a2856fd1d0a040c876ba9e3f89b949ae92e4dd","https://git.kernel.org/stable/c/e0322a255a2242dbe4686b6176b3c83dea490529","https://git.kernel.org/stable/c/e5de968a9032366198720eac4f368ed7e690b3ef","https://git.kernel.org/stable/c/ec9d118ad99dc6f1bc674c1e649c25533d89b9ba"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:18:08.089039631+00:00"},"epss":{"cve":"CVE-2023-54316","score":0.00191,"percentile":0.08802,"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."]}