[PATCH] sha1_file: don't convert off_t to size_t too early to avoid potential die()
- From
Steffen Prohaska <prohaska@zib.de>
- Date
- Sep 21, 2014, 10:03 UTC
- Message-ID
- <1411293806-3087-1-git-send-email-prohaska@zib.de>
xsize_t() checks if an off_t argument can be safely converted to a size_t return value. If the check is executed too early, it could fail for large files on 32-bit architectures even if the size_t code path is not taken. Other paths might be able to handle the large file. Specifically, index_stream_convert_blob() is able to handle a large file if a filter is configured that returns a small result.
Signed-off-by: Steffen Prohaska <prohaska@zib.de> ---
This patch should be applied on top of sp/stream-clean-filter.
index_stream() might internally also be able to handle large files to some extent. But it uses size_t for its third argument, and we must already die() when calling it. It might be a good idea to convert its interface to use off_t and push the size checks further down the stack. In general, it might be good idea to carefully consider whether to use off_t or size_t when passing file-related sizes around. To me it looks like a separate issue for a separate patch series (I have no specific plans to prepare one).
sha1_file.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/sha1_file.c b/sha1_file.c index 5b0e67a..6f18c22 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -3180,17 +3180,22 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, enum object_type type, const char *path, unsigned flags) { int ret; - size_t size = xsize_t(st->st_size); + /* + * Call xsize_t() only when needed to avoid potentially unnecessary + * die() for large files. + */ if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path)) ret = index_stream_convert_blob(sha1, fd, path, flags); else if (!S_ISREG(st->st_mode)) ret = index_pipe(sha1, fd, type, path, flags); - else if (size <= big_file_threshold || type != OBJ_BLOB || + else if (st->st_size <= big_file_threshold || type != OBJ_BLOB || (path && would_convert_to_git(path))) - ret = index_core(sha1, fd, size, type, path, flags); + ret = index_core(sha1, fd, xsize_t(st->st_size), type, path, + flags); else - ret = index_stream(sha1, fd, size, type, path, flags); + ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path, + flags); close(fd); return ret; }
-- 2.1.0.139.g351b19f