Am 10.11.2017 um 20:05 schrieb Elijah Newren:
> +static struct dir_rename_entry *check_dir_renamed(const char *path,
> + struct hashmap *dir_renames) {
> + char temp[PATH_MAX];
> + char *end;
> + struct dir_rename_entry *entry;
> +
> + strcpy(temp, path);
> + while ((end = strrchr(temp, '/'))) {
> + *end = '\0';
> + entry = dir_rename_find_entry(dir_renames, temp);
> + if (entry)
> + return entry;
> + }
> + return NULL;
> +}
The value of PATH_MAX is platform-dependent, so it's easy to exceed when
doing cross-platform development. It's also not a hard limit on most
operating systems, not even on Windows. Further reading:
https://insanecoding.blogspot.com/2007/11/pathmax-simply-isnt.html
So using a fixed buffer is not a good idea, and writing to it without
checking is dangerous. Here's a fix:
-- >8 --
Subject: [PATCH] merge-recursive: use xstrdup() instead of fixed buffer
Paths can be longer than PATH_MAX. Avoid a buffer overrun in
check_dir_renamed() by using xstrdup() to make a private copy safely.
Signed-off-by: Rene Scharfe <[email protected]>
---
merge-recursive.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/merge-recursive.c b/merge-recursive.c
index ac27abbd4c..db708176c5 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -2211,18 +2211,18 @@ static struct hashmap *get_directory_renames(struct
diff_queue_struct *pairs,
static struct dir_rename_entry *check_dir_renamed(const char *path,
struct hashmap *dir_renames)
{
- char temp[PATH_MAX];
+ char *temp = xstrdup(path);
char *end;
- struct dir_rename_entry *entry;
+ struct dir_rename_entry *entry = NULL;;
- strcpy(temp, path);
while ((end = strrchr(temp, '/'))) {
*end = '\0';
entry = dir_rename_find_entry(dir_renames, temp);
if (entry)
- return entry;
+ break;
}
- return NULL;
+ free(temp);
+ return entry;
}
static void compute_collisions(struct hashmap *collisions,
--
2.17.1
