CVE-2022-49030

In the Linux kernel, the following vulnerability has been resolved:

libbpf: Handle size overflow for ringbuf mmap

The maximum size of ringbuf is 2GB on x86-64 host, so 2 * max_entries

will overflow u32 when mapping producer page and data pages. Only

casting max_entries to size_t is not enough, because for 32-bits

application on 64-bits kernel the size of read-only mmap region

also could overflow size_t.

So fixing it by casting the size of read-only mmap region into a __u64

and checking whether or not there will be overflow during mmap.