[PATCH 4/5] builtin/mv: don't use memory after free
- From
John Keeping <john@keeping.me.uk>
- Date
- Feb 16, 2014, 16:06 UTC
- Message-ID
- <4df594e05741b2bec1201556d34eb22bab2c235a.1392565571.git.john@keeping.me.uk>
- In-Reply-To
- <cover.1392565571.git.john@keeping.me.uk>
If 'src' already ends with a slash, then add_slash() will just return it, meaning that 'free(src_with_slash)' is actually 'free(src)'. Since we use 'src' later, this will result in use-after-free.
In fact, this cannot happen because 'src' comes from internal_copy_pathspec() without the KEEP_TRAILING_SLASH flag, so any trailing '/' will have been stripped; but static analysis tools are not clever enough to realise this and so warn that 'src' could be used after having been free'd. Fix this by checking that 'src_w_slash' is indeed newly allocated memory.
Signed-off-by: John Keeping <john@keeping.me.uk> --- builtin/mv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/builtin/mv.c b/builtin/mv.c index 21c46d1..7e26eb5 100644 --- a/builtin/mv.c +++ b/builtin/mv.c @@ -162,7 +162,8 @@ int cmd_mv(int argc, const char **argv, const char *prefix) if (strncmp(path, src_w_slash, len_w_slash)) break; } - free((char *)src_w_slash); + if (src_w_slash != src) + free((char *)src_w_slash); if (last - first < 1) bad = _("source directory is empty");
-- 1.9.rc0.187.g6292fff