From: Pavel Raiskup Subject: [Bug-cpio] [PATCH] fix 1-byte out-of-bounds write Date: Tue, 26 Jan 2016 23:17:54 +0100 Other calls to cpio_safer_name_suffix seem to be safe. * src/copyin.c (process_copy_in): Make sure that file_hdr.c_name has at least two bytes allocated. * src/util.c (cpio_safer_name_suffix): Document that use of this function requires to be careful. Signed-off-by: Gustavo Zacarias --- Patch status: fetched/submitted URL: https://lists.gnu.org/archive/html/bug-cpio/2016-01/msg00005.html src/copyin.c | 2 ++ src/util.c | 5 ++++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/src/copyin.c b/src/copyin.c index cde911e..032d35f 100644 --- a/src/copyin.c +++ b/src/copyin.c @@ -1385,6 +1385,8 @@ process_copy_in () break; } + if (file_hdr.c_namesize <= 1) + file_hdr.c_name = xrealloc(file_hdr.c_name, 2); cpio_safer_name_suffix (file_hdr.c_name, false, !no_abs_paths_flag, false); diff --git a/src/util.c b/src/util.c index 6ff6032..2763ac1 100644 --- a/src/util.c +++ b/src/util.c @@ -1411,7 +1411,10 @@ set_file_times (int fd, } /* Do we have to ignore absolute paths, and if so, does the filename - have an absolute path? */ + have an absolute path? + Before calling this function make sure that the allocated NAME buffer has + capacity at least 2 bytes to allow us to store the "." string inside. */ + void cpio_safer_name_suffix (char *name, bool link_target, bool absolute_names, bool strip_leading_dots) -- 2.5.0