bpftool: Use appropriate permissions for map access

Modify several functions in tools/bpf/bpftool/common.c to allow
specification of requested access for file descriptors, such as
read-only access.

Update bpftool to request only read access for maps when write
access is not required. This fixes errors when reading from maps
that are protected from modification via security_bpf_map.

Signed-off-by: Slava Imameev <slava.imameev@crowdstrike.com>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20250620151812.13952-1-slava.imameev@crowdstrike.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 96eea8a67225..deeaa5c1ed7d 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -1062,7 +1062,7 @@ static int parse_attach_detach_args(int argc, char **argv, int *progfd,
 	if (!REQ_ARGS(2))
 		return -EINVAL;
 
-	*mapfd = map_parse_fd(&argc, &argv);
+	*mapfd = map_parse_fd(&argc, &argv, 0);
 	if (*mapfd < 0)
 		return *mapfd;
 
@@ -1608,7 +1608,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
 			}
 			NEXT_ARG();
 
-			fd = map_parse_fd(&argc, &argv);
+			fd = map_parse_fd(&argc, &argv, 0);
 			if (fd < 0)
 				goto err_free_reuse_maps;