From: Wenbo Zhang ethercflow@gmail.com
[ 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@gmail.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Andrii Nakryiko andriin@fb.com Link: https://lore.kernel.org/bpf/20200710092035.28919-1-ethercflow@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 d5992f7872328..59f45fef51109 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;