From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: + fat-dont-allow-to-mount-if-the-fat-length-==-0.patch added to -mm tree Date: Wed, 08 Apr 2020 18:07:50 -0700 Message-ID: <20200409010750.t3QDF5_Lo%akpm@linux-foundation.org> References: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:46026 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726555AbgDIBHv (ORCPT ); Wed, 8 Apr 2020 21:07:51 -0400 In-Reply-To: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: dvyukov@google.com, elver@google.com, hirofumi@mail.parknet.co.jp, mm-commits@vger.kernel.org The patch titled Subject: fat: don't allow to mount if the FAT length == 0 has been added to the -mm tree. Its filename is fat-dont-allow-to-mount-if-the-fat-length-==-0.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/fat-dont-allow-to-mount-if-the-fat-length-%3D%3D-0.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/fat-dont-allow-to-mount-if-the-fat-length-%3D%3D-0.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: OGAWA Hirofumi Subject: fat: don't allow to mount if the FAT length == 0 If FAT length == 0, the image doesn't have any data. And it can be the cause of overlapping the root dir and FAT entries. Also Windows treats it as invalid format. Link: http://lkml.kernel.org/r/87r1wz8mrd.fsf@mail.parknet.co.jp Reported-by: syzbot+6f1624f937d9d6911e2d@syzkaller.appspotmail.com Signed-off-by: OGAWA Hirofumi Cc: Marco Elver Cc: Dmitry Vyukov Signed-off-by: Andrew Morton --- fs/fat/inode.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/fat/inode.c~fat-dont-allow-to-mount-if-the-fat-length-==-0 +++ a/fs/fat/inode.c @@ -1520,6 +1520,12 @@ static int fat_read_bpb(struct super_blo goto out; } + if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) { + if (!silent) + fat_msg(sb, KERN_ERR, "bogus number of FAT sectors"); + goto out; + } + error = 0; out: _ Patches currently in -mm which might be from hirofumi@mail.parknet.co.jp are fat-dont-allow-to-mount-if-the-fat-length-==-0.patch