From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 References: <000000000000e59aab056e8873ae@google.com> In-Reply-To: <000000000000e59aab056e8873ae@google.com> From: Dmitry Vyukov Date: Wed, 5 Dec 2018 20:50:03 +0100 Message-ID: Subject: Re: KASAN: use-after-free Read in blkdev_get To: syzbot+eaeb616d85c9a0afec7d@syzkaller.appspotmail.com Cc: linux-fsdevel , LKML , syzkaller-bugs , Al Viro Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: On Wed, Jun 13, 2018 at 6:27 PM syzbot wrote: > > 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 Was this fixed by something? This happened 108 times in Jun-Aug, then last time on Sep 2, and then stopped happened since then. > 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 > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000e59aab056e8873ae%40google.com. > For more options, visit https://groups.google.com/d/optout.