bpf: Add oversize check before call kvcalloc()

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

bpf: Add oversize check before call kvcalloc()

Commit 7661809d493b ("mm: don't allow oversized kvmalloc() calls") add the

oversize check. When the allocation is larger than what kmalloc() supports,

the following warning triggered:

WARNING: CPU: 0 PID: 8408 at mm/util.c:597 kvmalloc_node+0x108/0x110 mm/util.c:597

Modules linked in:

CPU: 0 PID: 8408 Comm: syz-executor221 Not tainted 5.14.0-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

RIP: 0010:kvmalloc_node+0x108/0x110 mm/util.c:597

Call Trace:

kvmalloc include/linux/mm.h:806 [inline]

kvmalloc_array include/linux/mm.h:824 [inline]

kvcalloc include/linux/mm.h:829 [inline]

check_btf_line kernel/bpf/verifier.c:9925 [inline]

check_btf_info kernel/bpf/verifier.c:10049 [inline]

bpf_check+0xd634/0x150d0 kernel/bpf/verifier.c:13759

bpf_prog_load kernel/bpf/syscall.c:2301 [inline]

__sys_bpf+0x11181/0x126e0 kernel/bpf/syscall.c:4587

__do_sys_bpf kernel/bpf/syscall.c:4691 [inline]

__se_sys_bpf kernel/bpf/syscall.c:4689 [inline]

__x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4689

do_syscall_x64 arch/x86/entry/common.c:50 [inline]

do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80

entry_SYSCALL_64_after_hwframe+0x44/0xae