CVE-2026-64426

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> io_uring/nop: fix file reference leak with IOSQE_FIXED_FILE<br /> <br /> NOP file-acquisition support choses between a fixed (registered) file and<br /> a normal fget()&amp;#39;d file based on its own IORING_NOP_FIXED_FILE flag in<br /> sqe-&gt;nop_flags. However, a request&amp;#39;s REQ_F_FIXED_FILE is set<br /> independently from the generic IOSQE_FIXED_FILE sqe flag during request<br /> init, before the issue handler runs.<br /> <br /> If a NOP is submitted with IOSQE_FIXED_FILE set (so REQ_F_FIXED_FILE is<br /> set) but without IORING_NOP_FIXED_FILE, io_nop() takes the normal path<br /> and grabs a real reference via io_file_get_normal(). On completion,<br /> io_put_file() only drops the reference when REQ_F_FIXED_FILE is clear,<br /> so the fget()&amp;#39;d file is never released and leaks:<br /> <br /> BUG: memory leak<br /> unreferenced object 0xffff88800f42c240 (size 176):<br /> kmem_cache_alloc_noprof+0x358/0x440<br /> alloc_empty_file+0x57/0x180<br /> path_openat+0x44/0x1e50<br /> do_file_open+0x121/0x200<br /> do_sys_openat2+0xa7/0x150<br /> __x64_sys_openat+0x82/0xf0<br /> <br /> Decide between fixed and normal file acquisition from REQ_F_FIXED_FILE,<br /> the same way io_assign_file() does for every other opcode, and fold<br /> IORING_NOP_FIXED_FILE into REQ_F_FIXED_FILE at prep time.