CyberRota Analysis
AI-GeneratedThe vulnerability in the Linux kernel affects the Aspeed LPC snoop driver, where concurrent access to the kernel FIFO buffer can lead to a usercopy overflow, potentially allowing unauthorized access to kernel memory. This flaw can result in a kernel bug and memory exposure, particularly on SMP systems where synchronization between the IRQ handler and file reader is inadequate. Organizations using affected Linux systems, especially those with Aspeed hardware, should prioritize patching to mitigate the risk of memory corruption and unauthorized data access.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: soc: aspeed: lpc-snoop: Fix usercopy overflow in snoop_file_read put_fifo_with_discard() acts as both producer and consumer on the kfifo: it calls kfifo_skip() (advances out) and kfifo_put() (advances in) from the IRQ handler without synchronizing with snoop_file_read(), which also consumes via kfifo_to_user(). On SMP systems this concurrent access can leave (in - out) larger than the ring buffer, so __kfifo_to_user()'s clamp to (in - out) is ineffective and kfifo_copy_to_user() can attempt a copy_to_user() past the kmalloc-2k backing store: usercopy: Kernel memory exposure attempt detected from SLUB object 'kmalloc-2k' (offset 0, size 2049)! kernel BUG at mm/usercopy.c! Call trace: usercopy_abort __check_heap_object __check_object_size kfifo_copy_to_user __kfifo_to_user snoop_file_read vfs_read Serialize kfifo access with a per-channel spinlock shared between the IRQ handler (producer) and the file reader (consumer). Annotate @fifo with __guarded_by(&lock) and opt the driver into context analysis so the compiler enforces that all fifo access holds the lock.