Commit 082739aa authored May 25, 2015 by Daniel Borkmann Committed by David S. Miller May 27, 2015

tools: bpf_jit_disasm: fix segfault on disabled debugging log output

With recent debugging, I noticed that bpf_jit_disasm segfaults when
there's no debugging output from the JIT compiler to the kernel log.

Reason is that when regexec(3) doesn't match on anything, start/end
offsets are not being filled out and contain some uninitialized garbage
from stack. Thus, we need zero out offsets first.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent b48732e4

tools/net/bpf_jit_disasm.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -123,6 +123,8 @@ static int get_last_jit_image(char *haystack, size_t hlen,
	assert(ret == 0);		assert(ret == 0);

	ptr = haystack;		ptr = haystack;
			memset(pmatch, 0, sizeof(pmatch));

	while (1) {		while (1) {
	ret = regexec(&regex, ptr, 1, pmatch, 0);		ret = regexec(&regex, ptr, 1, pmatch, 0);
	if (ret == 0) {		if (ret == 0) {