{"cve":"CVE-2026-74729","nvd":{"published":"2026-08-22T16:16:48.033","modified":"2026-10-21T13:19:50.213","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsoc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read\n\nput_fifo_with_discard() acts as both producer and consumer on the kfifo:\nit calls kfifo_skip() (advances out) and kfifo_put() (advances in) from\nthe IRQ handler without synchronizing with snoop_file_read(), which also\nconsumes via kfifo_to_user(). On SMP systems this concurrent access can\nleave (in - out) larger than the ring buffer, so __kfifo_to_user()'s clamp\nto (in - out) is ineffective and kfifo_copy_to_user() can attempt a\ncopy_to_user() past the kmalloc-2k backing store:\n\n  usercopy: Kernel memory exposure attempt detected from SLUB object\n  'kmalloc-2k' (offset 0, size 2049)!\n  kernel BUG at mm/usercopy.c!\n  Call trace:\n   usercopy_abort\n   __check_heap_object\n   __check_object_size\n   kfifo_copy_to_user\n   __kfifo_to_user\n   snoop_file_read\n   vfs_read\n\nSerialize kfifo access with a per-channel spinlock shared between the\nIRQ handler (producer) and the file reader (consumer).  Annotate @fifo\nwith __guarded_by(&lock) and opt the driver into context analysis so the\ncompiler enforces that all fifo access holds the lock.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/131ab677b03349a5ae48da8722ec7075b37ec66e","https://git.kernel.org/stable/c/1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f","https://git.kernel.org/stable/c/868c478abce858135db3eb65548a577e4b6747ac","https://git.kernel.org/stable/c/afe2527eae0b51d5e8ddd77293afab3a5a1311a4","https://git.kernel.org/stable/c/b87c0d24386ed5106feac12034fe09d893ccb469"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-74729","score":0.00209,"percentile":0.10918,"date":"2026-10-26"},"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."]}