From 0d136425660428de8bcfaae372e7a2927cbe9124 Mon Sep 17 00:00:00 2001 From: GNU Libc Maintainers Date: Sun, 5 Dec 2021 15:46:21 +0000 Subject: [PATCH] submitted-localedef-check-magic commit 56ea4bed7369f32e3c7c935f9e33ee38e9f78143 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. Gbp-Pq: Topic any Gbp-Pq: Name submitted-localedef-check-magic.patch --- locale/programs/locarchive.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/locale/programs/locarchive.c b/locale/programs/locarchive.c index dccaf04e3..e2ae91189 100644 --- a/locale/programs/locarchive.c +++ b/locale/programs/locarchive.c @@ -655,6 +655,13 @@ 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; -- 2.30.2