Commit eef8a42d authored Jul 10, 2020 by Wenbo Zhang Committed by Daniel Borkmann Jul 10, 2020

bpf: Fix fds_example SIGSEGV error



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

parent 5c3320d7

samples/bpf/fds_example.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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;

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