diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/syscall.c | 25 |
1 files changed, 6 insertions, 19 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index c3ae2adaeccd..9693730833d2 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -74,32 +74,19 @@ int bpf_check_uarg_tail_zero(void __user *uaddr, size_t expected_size, size_t actual_size) { - unsigned char __user *addr; - unsigned char __user *end; - unsigned char val; - int err; + unsigned char __user *addr = uaddr + expected_size; + int res; if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ return -E2BIG; - if (unlikely(!access_ok(uaddr, actual_size))) - return -EFAULT; - if (actual_size <= expected_size) return 0; - addr = uaddr + expected_size; - end = uaddr + actual_size; - - for (; addr < end; addr++) { - err = get_user(val, addr); - if (err) - return err; - if (val) - return -E2BIG; - } - - return 0; + res = check_zeroed_user(addr, actual_size - expected_size); + if (res < 0) + return res; + return res ? 0 : -E2BIG; } const struct bpf_map_ops bpf_map_offload_ops = { |