bpf: program: Refuse non-O_RDWR flags in BPF_OBJ_GET

As for bpf_link, refuse creating a non-O_RDWR fd. Since program fds
currently don't allow modifications this is a precaution, not a
straight up bug fix.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210326160501.46234-2-lmb@cloudflare.com
This commit is contained in:
Lorenz Bauer 2021-03-26 16:05:01 +00:00 committed by Alexei Starovoitov
parent 25fc94b2f0
commit d37300ed18

View File

@ -543,7 +543,7 @@ int bpf_obj_get_user(const char __user *pathname, int flags)
return PTR_ERR(raw);
if (type == BPF_TYPE_PROG)
ret = bpf_prog_new_fd(raw);
ret = (f_flags != O_RDWR) ? -EINVAL : bpf_prog_new_fd(raw);
else if (type == BPF_TYPE_MAP)
ret = bpf_map_new_fd(raw, f_flags);
else if (type == BPF_TYPE_LINK)