From: Hou Tao <houtao1@xxxxxxxxxx>
get_map_btf() gets the btf from the btf fd and ensure the btf is not a
kernel btf.
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
kernel/bpf/syscall.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 6e14208cca813..ba2df15ae0f1f 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1345,6 +1345,21 @@ static bool bpf_net_capable(void)
return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN);
}
+static struct btf *get_map_btf(int btf_fd)
+{
+ struct btf *btf = btf_get_by_fd(btf_fd);
+
+ if (IS_ERR(btf))
+ return btf;
+
+ if (btf_is_kernel(btf)) {
+ btf_put(btf);
+ return ERR_PTR(-EACCES);
+ }
+
+ return btf;
+}
+
#define BPF_MAP_CREATE_LAST_FIELD map_token_fd
/* called via syscall */
static int map_create(union bpf_attr *attr)
--
2.29.2
