Re: What's cooking in git.git (Apr 2014, #08; Fri, 25)

On Fri, Apr 25, 2014 at 03:50:26PM -0700, Junio C Hamano wrote:

quoted

* jk/external-diff-use-argv-array (2014-04-21) 6 commits
  (merged to 'next' on 2014-04-22 at e6d92d7)
 + run_external_diff: refactor cmdline setup logic
 + run_external_diff: hoist common bits out of conditional
 + run_external_diff: drop fflush(NULL)
 + run_external_diff: clean up error handling
 + run_external_diff: use an argv_array for the environment
 + run_external_diff: use an argv_array for the command line

 Code clean-up.

 Will keep in 'next' for the remainder of the cycle.

The first one does fix a possible stack overflow (albeit of one NULL,
not arbitrary content, so I don't think it's exploitable). We may want
to do:

diff --git a/diff.c b/diff.c
index 54d5308..a03744b 100644
--- a/diff.c
+++ b/diff.c

@@ -2894,7 +2894,7 @@ static void run_external_diff(const char *pgm,
 			      int complete_rewrite,
 			      struct diff_options *o)
 {
-	const char *spawn_arg[10];
+	const char *spawn_arg[11];
 	int retval;
 	const char **arg = &spawn_arg[0];
 	struct diff_queue_struct *q = &diff_queued_diff;

as a fix for maint/2.0.0 in the interim. I can write a commit message
for that if you're interested.