From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B83FAC35669 for ; Sat, 22 Feb 2020 05:00:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8CBDC208C4 for ; Sat, 22 Feb 2020 05:00:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726329AbgBVFAK (ORCPT ); Sat, 22 Feb 2020 00:00:10 -0500 Received: from mail-io1-f72.google.com ([209.85.166.72]:35738 "EHLO mail-io1-f72.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id 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MIME-Version: 1.0 X-Received: by 2002:a92:7301:: with SMTP id o1mr40729644ilc.272.1582347609436; Fri, 21 Feb 2020 21:00:09 -0800 (PST) Date: Fri, 21 Feb 2020 21:00:09 -0800 In-Reply-To: <0000000000008a9e79059f1409f1@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000002bf78e059f2303c5@google.com> Subject: Re: KMSAN: uninit-value in fat_evict_inode From: syzbot To: akpm@linux-foundation.org, glider@google.com, hirofumi@mail.parknet.co.jp, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syzbot has found a reproducer for the following crash on: HEAD commit: 8bbbc5cf kmsan: don't compile memmove git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=11c3774ee00000 kernel config: https://syzkaller.appspot.com/x/.config?x=cd0e9a6b0e555cc3 dashboard link: https://syzkaller.appspot.com/bug?extid=9d82b8de2992579da5d0 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) userspace arch: i386 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=171ce265e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15bb1109e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+9d82b8de2992579da5d0@syzkaller.appspotmail.com FAT-fs (loop0): error, invalid access to FAT (entry 0x00006500) FAT-fs (loop0): Filesystem has been set read-only ===================================================== BUG: KMSAN: uninit-value in fat_free_eofblocks fs/fat/inode.c:628 [inline] BUG: KMSAN: uninit-value in fat_evict_inode+0x2f4/0x920 fs/fat/inode.c:658 CPU: 0 PID: 11199 Comm: syz-executor375 Not tainted 5.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 fat_free_eofblocks fs/fat/inode.c:628 [inline] fat_evict_inode+0x2f4/0x920 fs/fat/inode.c:658 evict+0x4ab/0xe10 fs/inode.c:575 iput_final fs/inode.c:1571 [inline] iput+0xa70/0xe10 fs/inode.c:1597 fat_build_inode+0x6a3/0x840 fs/fat/inode.c:610 vfat_mkdir+0x547/0x7d0 fs/fat/namei_vfat.c:871 vfs_mkdir+0x691/0x920 fs/namei.c:3889 do_mkdirat+0x39f/0x680 fs/namei.c:3912 __do_sys_mkdir fs/namei.c:3928 [inline] __se_sys_mkdir fs/namei.c:3926 [inline] __ia32_sys_mkdir+0x9f/0xd0 fs/namei.c:3926 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline] do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f1bd99 Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000ffb4ff4c EFLAGS: 00000292 ORIG_RAX: 0000000000000027 RAX: ffffffffffffffda RBX: 0000000020000740 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000ffb4ffbe RDI: 0000000000000001 RBP: 00000000000000c2 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144 kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:307 [inline] kmsan_alloc_page+0x12a/0x310 mm/kmsan/kmsan_shadow.c:336 __alloc_pages_nodemask+0x5712/0x5e80 mm/page_alloc.c:4775 alloc_pages_current+0x67d/0x990 mm/mempolicy.c:2211 alloc_pages include/linux/gfp.h:534 [inline] alloc_slab_page+0x111/0x12f0 mm/slub.c:1530 allocate_slab mm/slub.c:1675 [inline] new_slab+0x2bc/0x1130 mm/slub.c:1741 new_slab_objects mm/slub.c:2492 [inline] ___slab_alloc+0x1533/0x1f30 mm/slub.c:2643 __slab_alloc mm/slub.c:2683 [inline] slab_alloc_node mm/slub.c:2757 [inline] slab_alloc mm/slub.c:2802 [inline] kmem_cache_alloc+0xb23/0xd70 mm/slub.c:2807 fat_alloc_inode+0x58/0x120 fs/fat/inode.c:748 alloc_inode fs/inode.c:231 [inline] new_inode_pseudo+0xb1/0x590 fs/inode.c:927 new_inode+0x5a/0x3d0 fs/inode.c:956 fat_fill_super+0x634b/0x89b0 fs/fat/inode.c:1844 vfat_fill_super+0xa6/0xc0 fs/fat/namei_vfat.c:1050 mount_bdev+0x654/0x880 fs/super.c:1417 vfat_mount+0xc9/0xe0 fs/fat/namei_vfat.c:1057 legacy_get_tree+0x169/0x2e0 fs/fs_context.c:622 vfs_get_tree+0xdd/0x580 fs/super.c:1547 do_new_mount fs/namespace.c:2822 [inline] do_mount+0x365c/0x4ac0 fs/namespace.c:3107 __do_compat_sys_mount fs/compat.c:122 [inline] __se_compat_sys_mount+0x3a8/0xa10 fs/compat.c:89 __ia32_compat_sys_mount+0x157/0x1b0 fs/compat.c:89 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline] do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139 =====================================================