{"id":"CVE-2026-64426","summary":"io_uring/nop: fix file reference leak with IOSQE_FIXED_FILE","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/nop: fix file reference leak with IOSQE_FIXED_FILE\n\nNOP file-acquisition support choses between a fixed (registered) file and\na normal fget()'d file based on its own IORING_NOP_FIXED_FILE flag in\nsqe-\u003enop_flags. However, a request's REQ_F_FIXED_FILE is set\nindependently from the generic IOSQE_FIXED_FILE sqe flag during request\ninit, before the issue handler runs.\n\nIf a NOP is submitted with IOSQE_FIXED_FILE set (so REQ_F_FIXED_FILE is\nset) but without IORING_NOP_FIXED_FILE, io_nop() takes the normal path\nand grabs a real reference via io_file_get_normal(). On completion,\nio_put_file() only drops the reference when REQ_F_FIXED_FILE is clear,\nso the fget()'d file is never released and leaks:\n\n  BUG: memory leak\n  unreferenced object 0xffff88800f42c240 (size 176):\n    kmem_cache_alloc_noprof+0x358/0x440\n    alloc_empty_file+0x57/0x180\n    path_openat+0x44/0x1e50\n    do_file_open+0x121/0x200\n    do_sys_openat2+0xa7/0x150\n    __x64_sys_openat+0x82/0xf0\n\nDecide between fixed and normal file acquisition from REQ_F_FIXED_FILE,\nthe same way io_assign_file() does for every other opcode, and fold\nIORING_NOP_FIXED_FILE into REQ_F_FIXED_FILE at prep time.","modified":"2026-07-27T04:03:19.891180349Z","published":"2026-07-25T08:51:03.867Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64426.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2564ca2e31bd8ee8348362941af2ee4671e487ca"},{"type":"WEB","url":"https://git.kernel.org/stable/c/722869fcff598fad20d5ab79c305897a7534708b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7267717f35787167fcce4bc14f6ef3fa06682dcf"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64426.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64426"},{"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":"a85f31052bce52111b4e9d5a536003481d0421d0"},{"fixed":"722869fcff598fad20d5ab79c305897a7534708b"},{"fixed":"7267717f35787167fcce4bc14f6ef3fa06682dcf"},{"fixed":"2564ca2e31bd8ee8348362941af2ee4671e487ca"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64426.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.39"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64426.json"}}],"schema_version":"1.7.5"}