{"id":"CVE-2026-74729","summary":"soc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read","details":"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.","modified":"2026-08-24T11:47:24.736073836Z","published":"2026-08-22T15:33:19.037Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74729.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/131ab677b03349a5ae48da8722ec7075b37ec66e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74729.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74729"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3772e5da445420543b25825ac2b5971f3743f6e8"},{"fixed":"131ab677b03349a5ae48da8722ec7075b37ec66e"},{"fixed":"1acef6d85bfd98bd9dfe1f08bffa397a4dda8a6f"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74729.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.19.0"},{"fixed":"7.1.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74729.json"}}],"schema_version":"1.9.0"}