From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f198.google.com ([209.85.223.198]:46549 "EHLO mail-io0-f198.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934533AbeFMQ1D (ORCPT ); Wed, 13 Jun 2018 12:27:03 -0400 Received: by mail-io0-f198.google.com with SMTP id m15-v6so2589536ioj.13 for ; Wed, 13 Jun 2018 09:27:02 -0700 (PDT) MIME-Version: 1.0 Date: Wed, 13 Jun 2018 09:27:02 -0700 Message-ID: <000000000000e59aab056e8873ae@google.com> Subject: KASAN: use-after-free Read in blkdev_get From: syzbot To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Hello, syzbot found the following crash on: HEAD commit: f5b7769eb040 Revert "debugfs: inode: debugfs_create_dir us.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=171dc837800000 kernel config: https://syzkaller.appspot.com/x/.config?x=709f8187af941e84 dashboard link: https://syzkaller.appspot.com/bug?extid=eaeb616d85c9a0afec7d compiler: gcc (GCC) 8.0.1 20180413 (experimental) syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=177f898f800000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=147eb85f800000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+eaeb616d85c9a0afec7d@syzkaller.appspotmail.com reiserfs: using flush barriers REISERFS warning (device loop4): sh-2022 reiserfs_fill_super: unable to initialize journal space REISERFS (device loop3): using ordered data mode reiserfs: using flush barriers ================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3888/0x5140 kernel/locking/lockdep.c:3314 Read of size 8 at addr ffff8801a78932f8 by task syz-executor927/4536 CPU: 1 PID: 4536 Comm: syz-executor927 Not tainted 4.17.0+ #100 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+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __lock_acquire+0x3888/0x5140 kernel/locking/lockdep.c:3314 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3924 __mutex_lock_common kernel/locking/mutex.c:757 [inline] __mutex_lock+0x16d/0x17f0 kernel/locking/mutex.c:894 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909 blkdev_get+0x5d8/0xb30 fs/block_dev.c:1620 blkdev_get_by_dev+0x3f/0x80 fs/block_dev.c:1736 journal_init_dev fs/reiserfs/journal.c:2628 [inline] journal_init+0xcad/0x6a20 fs/reiserfs/journal.c:2775 reiserfs_fill_super+0xd59/0x3900 fs/reiserfs/super.c:2034 mount_bdev+0x30c/0x3e0 fs/super.c:1174 get_super_block+0x34/0x40 fs/reiserfs/super.c:2605 mount_fs+0xae/0x328 fs/super.c:1277 vfs_kern_mount.part.34+0xd4/0x4d0 fs/namespace.c:1037 vfs_kern_mount fs/namespace.c:1027 [inline] do_new_mount fs/namespace.c:2518 [inline] do_mount+0x564/0x30b0 fs/namespace.c:2848 ksys_mount+0x12d/0x140 fs/namespace.c:3064 __do_sys_mount fs/namespace.c:3078 [inline] __se_sys_mount fs/namespace.c:3075 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x446fda Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 1d aa fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 fa a9 fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007fffcf4ce188 EFLAGS: 00000297 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fffcf4ce1a0 RCX: 0000000000446fda RDX: 00007fffcf4ce1a0 RSI: 0000000020000100 RDI: 00007fffcf4ce1c0 RBP: 0000000000000001 R08: 00007fffcf4ce200 R09: 000000000000000a R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000003 R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000001 Allocated by task 4536: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554 bdev_alloc_inode+0x1b/0x40 fs/block_dev.c:727 alloc_inode+0x63/0x190 fs/inode.c:210 new_inode_pseudo+0x69/0x1a0 fs/inode.c:895 new_inode+0x1c/0x40 fs/inode.c:924 iget5_locked+0x126/0x190 fs/inode.c:1097 bdget+0xb1/0x5c0 fs/block_dev.c:868 blkdev_get_by_dev+0x24/0x80 fs/block_dev.c:1732 journal_init_dev fs/reiserfs/journal.c:2628 [inline] journal_init+0xcad/0x6a20 fs/reiserfs/journal.c:2775 reiserfs_fill_super+0xd59/0x3900 fs/reiserfs/super.c:2034 mount_bdev+0x30c/0x3e0 fs/super.c:1174 get_super_block+0x34/0x40 fs/reiserfs/super.c:2605 mount_fs+0xae/0x328 fs/super.c:1277 vfs_kern_mount.part.34+0xd4/0x4d0 fs/namespace.c:1037 vfs_kern_mount fs/namespace.c:1027 [inline] do_new_mount fs/namespace.c:2518 [inline] do_mount+0x564/0x30b0 fs/namespace.c:2848 ksys_mount+0x12d/0x140 fs/namespace.c:3064 __do_sys_mount fs/namespace.c:3078 [inline] __se_sys_mount fs/namespace.c:3075 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 2414: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x2d0 mm/slab.c:3756 bdev_i_callback+0x20/0x30 fs/block_dev.c:738 __rcu_reclaim kernel/rcu/rcu.h:178 [inline] rcu_do_batch kernel/rcu/tree.c:2558 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2818 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2785 [inline] rcu_process_callbacks+0xe9d/0x1760 kernel/rcu/tree.c:2802 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:284 The buggy address belongs to the object at ffff8801a7893280 which belongs to the cache bdev_cache of size 1352 The buggy address is located 120 bytes inside of 1352-byte region [ffff8801a7893280, ffff8801a78937c8) The buggy address belongs to the page: page:ffffea00069e24c0 count:1 mapcount:0 mapping:ffff8801da9874c0 index:0xffff8801a7893ffe flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea0006dfab08 ffffea00069e2508 ffff8801da9874c0 raw: ffff8801a7893ffe ffff8801a7893280 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801a7893180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801a7893200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801a7893280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801a7893300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801a7893380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches