[PATCH 5.4 074/270] bpf: Fix fds_example SIGSEGV error

[Greg Kroah-Hartman]

From: Wenbo Zhang <ethercflow@xxxxxxxxx>

[ Upstream commit eef8a42d6ce087d1c81c960ae0d14f955b742feb ]

The `BPF_LOG_BUF_SIZE`'s value is `UINT32_MAX >> 8`, so define an array
with it on stack caused an overflow.

Signed-off-by: Wenbo Zhang <ethercflow@xxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Andrii Nakryiko <andriin@xxxxxx>
Link: https://lore.kernel.org/bpf/20200710092035.28919-1-ethercflow@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 samples/bpf/fds_example.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c
index 2d4b717726b64..34b3fca788e8d 100644
--- a/samples/bpf/fds_example.c
+++ b/samples/bpf/fds_example.c
@@ -30,6 +30,8 @@
 #define BPF_M_MAP	1
 #define BPF_M_PROG	2
 
+char bpf_log_buf[BPF_LOG_BUF_SIZE];
+
 static void usage(void)
 {
 	printf("Usage: fds_example [...]\n");
@@ -57,7 +59,6 @@ static int bpf_prog_create(const char *object)
 		BPF_EXIT_INSN(),
 	};
 	size_t insns_cnt = sizeof(insns) / sizeof(struct bpf_insn);
-	char bpf_log_buf[BPF_LOG_BUF_SIZE];
 	struct bpf_object *obj;
 	int prog_fd;
 
-- 
2.25.1