From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1778) id 6A0623858C2C; Tue, 7 Dec 2021 22:33:07 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6A0623858C2C Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Aurelien Jarno To: glibc-cvs@sourceware.org Subject: [glibc] localedef: check magic value on archive load [BZ #28650] X-Act-Checkin: glibc X-Git-Author: Aurelien Jarno X-Git-Refname: refs/heads/master X-Git-Oldrev: ceeffe968c01b1202e482f4855cb6baf5c6cb713 X-Git-Newrev: cbab7f726877badc5059316e7248be7c3bff9d96 Message-Id: <20211207223307.6A0623858C2C@sourceware.org> Date: Tue, 7 Dec 2021 22:33:07 +0000 (GMT) X-BeenThere: glibc-cvs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Glibc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Dec 2021 22:33:07 -0000 https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=cbab7f726877badc5059316e7248be7c3bff9d96 commit cbab7f726877badc5059316e7248be7c3bff9d96 Author: Aurelien Jarno Date: Sun Dec 5 11:51:17 2021 +0100 localedef: check magic value on archive load [BZ #28650] localedef currently blindly trust the archive header. When passed an archive file with the wrong endianess, this leads to a segmentation fault: $ localedef --big-endian --list-archive /usr/lib/locale/locale-archive Segmentation fault (core dumped) When passed non-archive files, asserts are reported on the best case, but sometimes it can lead to a segmentation fault: $ localedef --list-archive /bin/true localedef: programs/locarchive.c:1643: show_archive_content: Assertion `used < GET (head->namehash_used)' failed. Aborted (core dumped) $ localedef --list-archive /usr/lib/locale/C.utf8/LC_COLLATE Segmentation fault (core dumped) This patch improves the user experience by looking at the magic value, which is always written, but never checked. It should still be possible to trigger a segmentation fault with crafted files, but this already catch many cases. Diff: --- locale/programs/locarchive.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/locale/programs/locarchive.c b/locale/programs/locarchive.c index eeec3ab648..477499bd40 100644 --- a/locale/programs/locarchive.c +++ b/locale/programs/locarchive.c @@ -654,6 +654,13 @@ open_archive (struct locarhandle *ah, bool readonly) error (EXIT_FAILURE, errno, _("cannot read archive header")); } + /* Check the magic value */ + if (GET (head.magic) != AR_MAGIC) + { + (void) lockf64 (fd, F_ULOCK, sizeof (struct locarhead)); + error (EXIT_FAILURE, 0, _("bad magic value in archive header")); + } + ah->fd = fd; ah->mmaped = st.st_size;