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=-8.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 5BA70C433E0 for ; Wed, 24 Mar 2021 10:02:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 23BED619EC for ; Wed, 24 Mar 2021 10:02:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230105AbhCXKBg (ORCPT ); Wed, 24 Mar 2021 06:01:36 -0400 Received: from mail-il1-f198.google.com ([209.85.166.198]:41353 "EHLO mail-il1-f198.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233079AbhCXKBH (ORCPT ); Wed, 24 Mar 2021 06:01:07 -0400 Received: by mail-il1-f198.google.com with SMTP id g11so1172475ilc.8 for ; Wed, 24 Mar 2021 03:01:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:in-reply-to:message-id:subject :from:to; bh=vD5Utbm9xmIIiZwit6EwguADyscXHMVaPMZvjoGzSHs=; b=rck4MUtrIW3oqISSxBQksMdFoSzETx5bJaqV2864e8i0y6KwL/UxJWQNgGUZUxznjB S3dH2rjbm2CRciW1rh3QQaSpw+IQPjQGTh5c1Dnxz9ENU+z1D7ocF7V20wL35qwz34iv b02Q96sLR2tdUKbI3plXJfDpa4B1OzNnKZqT2vwRBlxpBp9aqTFd2Olr4Hl9bBwYimmN 1wP7IK0ZWi5K86784YygOieDvMq80wDqxHh1tXb7iN9ulaJvPEB184b0xK4YpUFlCCE+ owKwl3YMuo29J4zYnRjLbFXMmhvxbUvPXB8Y0GzcuQs1qy9xirmewd57HsZxTlLyYgib jMsQ== X-Gm-Message-State: AOAM531vJ1TUETRJLphjaEZxXUGSGu5vqOYCCi+MsptLWA7E9Lu53pqx fmDm/AB8ZU/dYyEfabx4K3XmunZWfmGosg4HjmrEfRBurI8z X-Google-Smtp-Source: ABdhPJwDLJH1RJvr0AuYzPBYVjrSVu3L2BIouTVb3mGWZIG7WKeXCoGVFcN0VGONfxUhTWwoVhIcCOo30uORwW4WZuPjLiKvXRK+ MIME-Version: 1.0 X-Received: by 2002:a5e:db47:: with SMTP id r7mr1798485iop.47.1616580066656; Wed, 24 Mar 2021 03:01:06 -0700 (PDT) Date: Wed, 24 Mar 2021 03:01:06 -0700 In-Reply-To: <20210324094947.GA9252@lst.de> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000009fc38f05be456045@google.com> Subject: Re: [syzbot] KASAN: use-after-free Read in disk_part_iter_next (2) From: syzbot To: axboe@kernel.dk, hch@lst.de, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tj@kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: KASAN: use-after-free Read in bdgrab ================================================================== BUG: KASAN: use-after-free in bdgrab+0x4c/0x50 fs/block_dev.c:929 Read of size 8 at addr ffff88801639a2a8 by task syz-executor.0/10133 CPU: 1 PID: 10133 Comm: syz-executor.0 Not tainted 5.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 bdgrab+0x4c/0x50 fs/block_dev.c:929 first_partition+0xfa/0x230 block/partitions/core.c:538 blk_drop_partitions+0xb5/0xf0 block/partitions/core.c:555 bdev_disk_changed+0x238/0x430 fs/block_dev.c:1237 __loop_clr_fd+0x7c7/0xff0 drivers/block/loop.c:1271 lo_release+0x1ac/0x1f0 drivers/block/loop.c:1923 __blkdev_put+0x54e/0x800 fs/block_dev.c:1579 blkdev_put+0x92/0x580 fs/block_dev.c:1632 blkdev_close+0x8c/0xb0 fs/block_dev.c:1640 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:140 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x41926b Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007fff13e6a990 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 000000000041926b RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b2fb20070 R10: 0000000000000000 R11: 0000000000000293 R12: 000000000056c9e0 R13: 000000000056c9e0 R14: 000000000056bf60 R15: 000000000001383c Allocated by task 10136: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:427 [inline] __kasan_slab_alloc+0x75/0x90 mm/kasan/common.c:460 kasan_slab_alloc include/linux/kasan.h:223 [inline] slab_post_alloc_hook mm/slab.h:516 [inline] slab_alloc_node mm/slub.c:2907 [inline] slab_alloc mm/slub.c:2915 [inline] kmem_cache_alloc+0x155/0x370 mm/slub.c:2920 bdev_alloc_inode+0x18/0x80 fs/block_dev.c:786 alloc_inode+0x61/0x230 fs/inode.c:234 new_inode_pseudo fs/inode.c:928 [inline] new_inode+0x27/0x2f0 fs/inode.c:957 bdev_alloc+0x20/0x2f0 fs/block_dev.c:876 add_partition+0x1ab/0x8a0 block/partitions/core.c:348 bdev_add_partition+0xb6/0x130 block/partitions/core.c:451 blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43 blkpg_ioctl block/ioctl.c:60 [inline] blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548 block_ioctl+0xf9/0x140 fs/block_dev.c:1658 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 4849: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357 ____kasan_slab_free mm/kasan/common.c:360 [inline] ____kasan_slab_free mm/kasan/common.c:325 [inline] __kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:199 [inline] slab_free_hook mm/slub.c:1562 [inline] slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600 slab_free mm/slub.c:3161 [inline] kmem_cache_free+0x8a/0x740 mm/slub.c:3177 i_callback+0x3f/0x70 fs/inode.c:223 rcu_do_batch kernel/rcu/tree.c:2559 [inline] rcu_core+0x74a/0x12f0 kernel/rcu/tree.c:2794 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 Last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345 __call_rcu kernel/rcu/tree.c:3039 [inline] call_rcu+0xb1/0x740 kernel/rcu/tree.c:3114 destroy_inode+0x129/0x1b0 fs/inode.c:289 iput_final fs/inode.c:1654 [inline] iput.part.0+0x57e/0x810 fs/inode.c:1680 iput+0x58/0x70 fs/inode.c:1670 blk_drop_partitions+0x9d/0xf0 block/partitions/core.c:557 bdev_disk_changed+0x238/0x430 fs/block_dev.c:1237 loop_reread_partitions+0x29/0x50 drivers/block/loop.c:655 loop_set_status+0x704/0x1050 drivers/block/loop.c:1418 loop_set_status64 drivers/block/loop.c:1538 [inline] lo_ioctl+0x4ca/0x1620 drivers/block/loop.c:1706 blkdev_ioctl+0x2a1/0x6d0 block/ioctl.c:583 block_ioctl+0xf9/0x140 fs/block_dev.c:1658 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88801639a280 which belongs to the cache bdev_cache of size 2792 The buggy address is located 40 bytes inside of 2792-byte region [ffff88801639a280, ffff88801639ad68) The buggy address belongs to the page: page:ffffea000058e600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16398 head:ffffea000058e600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff8880101bdb40 raw: 0000000000000000 00000000800b000b 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801639a180: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ffff88801639a200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801639a280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801639a300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801639a380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Tested on: commit: 7b997e8f block: simplify partition removal git tree: git://git.infradead.org/users/hch/block.git part-iter-fix console output: https://syzkaller.appspot.com/x/log.txt?x=14d147aed00000 kernel config: https://syzkaller.appspot.com/x/.config?x=c000f42ea85d0228 dashboard link: https://syzkaller.appspot.com/bug?extid=8fede7e30c7cee0de139 compiler: