[PATCH bpf] Revert "bpf: program: Refuse non-O_RDWR flags in BPF_OBJ_GET"

[Maciej Żenczykowski]

From: Maciej Żenczykowski <maze@xxxxxxxxxx>

This reverts commit d37300ed182131f1757895a62e556332857417e5.

This breaks Android userspace which expects to be able to
fetch programs with just read permissions.

See: https://cs.android.com/android/platform/superproject/+/master:frameworks/libs/net/common/native/bpf_syscall_wrappers/include/BpfSyscallWrappers.h;drc=7005c764be23d31fa1d69e826b4a2f6689a8c81e;l=124

Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxx>
Cc: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
Fixes: d37300ed1821 ("bpf: program: Refuse non-O_RDWR flags in BPF_OBJ_GET")
Signed-off-by: Maciej Żenczykowski <maze@xxxxxxxxxx>
---
 kernel/bpf/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index b4ebd60a6c16..80da1db47c68 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -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 = (f_flags != O_RDWR) ? -EINVAL : bpf_prog_new_fd(raw);
+		ret = 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)
-- 
2.32.0.288.g62a8d224e6-goog