[PATCH 23/68] add_packed_git: convert strcpy into xsnprintf
From: Jeff King <hidden>
Date: 2016-06-15 23:06:41
Subsystem:
the rest · Maintainer:
Linus Torvalds
We have the path "foo.idx", and we create a buffer big enough to hold "foo.pack" and "foo.keep", and then strcpy straight into it. This isn't a bug (we have enough space), but it's very hard to tell from the strcpy that this is so. Let's instead use strip_suffix to take off the ".idx", record the size of our allocation, and use xsnprintf to make sure we don't violate our assumptions. Signed-off-by: Jeff King <redacted> --- cache.h | 2 +- sha1_file.c | 21 +++++++++++++-------- 2 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/cache.h b/cache.h
index 030b880..d206d64 100644
--- a/cache.h
+++ b/cache.h@@ -1309,7 +1309,7 @@ extern void close_pack_windows(struct packed_git *); extern void unuse_pack(struct pack_window **); extern void free_pack_by_name(const char *); extern void clear_delta_base_cache(void); -extern struct packed_git *add_packed_git(const char *, int, int); +extern struct packed_git *add_packed_git(const char *path, size_t path_len, int local); /* * Return the SHA-1 of the nth object within the specified packfile.
diff --git a/sha1_file.c b/sha1_file.c
index f106091..592226e 100644
--- a/sha1_file.c
+++ b/sha1_file.c@@ -1146,11 +1146,12 @@ static void try_to_free_pack_memory(size_t size) release_pack_memory(size); } -struct packed_git *add_packed_git(const char *path, int path_len, int local) +struct packed_git *add_packed_git(const char *path, size_t path_len, int local) { static int have_set_try_to_free_routine; struct stat st; - struct packed_git *p = alloc_packed_git(path_len + 2); + size_t alloc; + struct packed_git *p; if (!have_set_try_to_free_routine) { have_set_try_to_free_routine = 1;
@@ -1161,18 +1162,22 @@ struct packed_git *add_packed_git(const char *path, int path_len, int local) * Make sure a corresponding .pack file exists and that * the index looks sane. */ - path_len -= strlen(".idx"); - if (path_len < 1) { - free(p); + if (!strip_suffix_mem(path, &path_len, ".idx")) return NULL; - } + + /* + * ".pack" is long enough to hold any suffix we're adding (and + * the use xsnprintf double-checks that) + */ + alloc = path_len + strlen(".pack") + 1; + p = alloc_packed_git(alloc); memcpy(p->pack_name, path, path_len); - strcpy(p->pack_name + path_len, ".keep"); + xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep"); if (!access(p->pack_name, F_OK)) p->pack_keep = 1; - strcpy(p->pack_name + path_len, ".pack"); + xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack"); if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) { free(p); return NULL;
--
2.6.0.rc3.454.g204ad51