Commit acd143ee authored by Jean-Philippe Brucker's avatar Jean-Philippe Brucker Committed by Andrii Nakryiko
Browse files

selftests/bpf: Fix segfault in bpf_tcp_ca 



Since commit ad9a7f96 ("libbpf: Improve logging around BPF program
loading"), libbpf_debug_print() gets an additional prog_name parameter
but doesn't pass it to printf(). Since the format string now expects two
arguments, printf() may read uninitialized data and segfault. Pass
prog_name through.

Fixes: ad9a7f96 ("libbpf: Improve logging around BPF program loading")
Signed-off-by: default avatarJean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211213183058.346066-1-jean-philippe@linaro.org
parent c8064e5b

tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c

+3 −4
Original line number Diff line number Diff line
@@ -217,7 +217,7 @@ static bool found; 
static int libbpf_debug_print(enum libbpf_print_level level,

			      const char *format, va_list args)

{

	const char *log_buf;

	const char *prog_name, *log_buf;



	if (level != LIBBPF_WARN ||

	    !strstr(format, "-- BEGIN PROG LOAD LOG --")) {
@@ -225,15 +225,14 @@ static int libbpf_debug_print(enum libbpf_print_level level, 
		return 0;

	}



	/* skip prog_name */

	va_arg(args, char *);

	prog_name = va_arg(args, char *);

	log_buf = va_arg(args, char *);

	if (!log_buf)

		goto out;

	if (err_str && strstr(log_buf, err_str) != NULL)

		found = true;

out:

	printf(format, log_buf);

	printf(format, prog_name, log_buf);

	return 0;

}