apply: avoid possible bogus pointer

When parsing "index" lines from a git-diff, we look for a
space followed by the mode. If we don't have a space, then
we set our pointer to the end-of-line. However, we don't
double-check that our end-of-line pointer is valid (e.g., if
we got a truncated diff input), which could lead to some
wrap-around pointer arithmetic.

In most cases this would probably get caught by our "40 <
len" check later in the function, but to be on the safe
side, let's just use strchrnul to treat end-of-string the
same as end-of-line.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/apply.c b/builtin/apply.c
index 87439fad118a2671989120dd5993a17b4541e2db..5b7a3066adca5912b2ac2551a89f74531decb9aa 100644 (file)
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -1073,7 +1073,7 @@ static int gitdiff_index(const char *line, struct patch *patch)
 
        line = ptr + 2;
        ptr = strchr(line, ' ');
-       eol = strchr(line, '\n');
+       eol = strchrnul(line, '\n');
 
        if (!ptr || eol < ptr)
                ptr = eol;