From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-f69.google.com ([209.85.166.69]:40518 "EHLO mail-io1-f69.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726052AbfF0GuH (ORCPT ); Thu, 27 Jun 2019 02:50:07 -0400 Received: by mail-io1-f69.google.com with SMTP id v11so1508136iop.7 for ; Wed, 26 Jun 2019 23:50:06 -0700 (PDT) MIME-Version: 1.0 Date: Wed, 26 Jun 2019 23:50:06 -0700 Message-ID: <000000000000783d99058c489257@google.com> Subject: KASAN: use-after-free Read in xlog_alloc_log From: syzbot Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: darrick.wong@oracle.com, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, syzkaller-bugs@googlegroups.com Hello, syzbot found the following crash on: HEAD commit: 1dd45f17 Add linux-next specific files for 20190626 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=172479e9a00000 kernel config: https://syzkaller.appspot.com/x/.config?x=c1222640552e42a5 dashboard link: https://syzkaller.appspot.com/bug?extid=b75afdbe271a0d7ac4f6 compiler: gcc (GCC) 9.0.0 20181231 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+b75afdbe271a0d7ac4f6@syzkaller.appspotmail.com XFS (loop5): Mounting V4 Filesystem ================================================================== BUG: KASAN: use-after-free in xlog_alloc_log+0x1266/0x1380 fs/xfs/xfs_log.c:1478 Read of size 8 at addr ffff8880693e2990 by task syz-executor.5/12241 CPU: 1 PID: 12241 Comm: syz-executor.5 Not tainted 5.2.0-rc6-next-20190626 #23 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x17 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 xlog_alloc_log+0x1266/0x1380 fs/xfs/xfs_log.c:1478 xfs_log_mount+0xdc/0x780 fs/xfs/xfs_log.c:580 xfs_mountfs+0xdb9/0x1be0 fs/xfs/xfs_mount.c:815 xfs_fs_fill_super+0xca6/0x16c0 fs/xfs/xfs_super.c:1740 mount_bdev+0x304/0x3c0 fs/super.c:1346 xfs_fs_mount+0x35/0x40 fs/xfs/xfs_super.c:1814 legacy_get_tree+0x108/0x220 fs/fs_context.c:661 vfs_get_tree+0x8e/0x390 fs/super.c:1476 do_new_mount fs/namespace.c:2791 [inline] do_mount+0x138c/0x1c00 fs/namespace.c:3111 ksys_mount+0xdb/0x150 fs/namespace.c:3320 __do_sys_mount fs/namespace.c:3334 [inline] __se_sys_mount fs/namespace.c:3331 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3331 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45bf6a Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 9d 8d 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 7a 8d fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007fac99605a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fac99605b40 RCX: 000000000045bf6a RDX: 00007fac99605ae0 RSI: 0000000020000000 RDI: 00007fac99605b00 RBP: 0000000000000001 R08: 00007fac99605b40 R09: 00007fac99605ae0 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000004 R13: 00000000004c858e R14: 00000000004df0e0 R15: 00000000ffffffff Allocated by task 12241: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x163/0x770 mm/slab.c:3665 kmalloc include/linux/slab.h:556 [inline] kmem_alloc+0xd2/0x200 fs/xfs/kmem.c:24 kmem_zalloc fs/xfs/kmem.h:73 [inline] xlog_alloc_log+0xbf4/0x1380 fs/xfs/xfs_log.c:1420 xfs_log_mount+0xdc/0x780 fs/xfs/xfs_log.c:580 xfs_mountfs+0xdb9/0x1be0 fs/xfs/xfs_mount.c:815 xfs_fs_fill_super+0xca6/0x16c0 fs/xfs/xfs_super.c:1740 mount_bdev+0x304/0x3c0 fs/super.c:1346 xfs_fs_mount+0x35/0x40 fs/xfs/xfs_super.c:1814 legacy_get_tree+0x108/0x220 fs/fs_context.c:661 vfs_get_tree+0x8e/0x390 fs/super.c:1476 do_new_mount fs/namespace.c:2791 [inline] do_mount+0x138c/0x1c00 fs/namespace.c:3111 ksys_mount+0xdb/0x150 fs/namespace.c:3320 __do_sys_mount fs/namespace.c:3334 [inline] __se_sys_mount fs/namespace.c:3331 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3331 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 12241: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 kvfree+0x61/0x70 mm/util.c:488 kmem_free fs/xfs/kmem.h:66 [inline] xlog_alloc_log+0xea9/0x1380 fs/xfs/xfs_log.c:1480 xfs_log_mount+0xdc/0x780 fs/xfs/xfs_log.c:580 xfs_mountfs+0xdb9/0x1be0 fs/xfs/xfs_mount.c:815 xfs_fs_fill_super+0xca6/0x16c0 fs/xfs/xfs_super.c:1740 mount_bdev+0x304/0x3c0 fs/super.c:1346 xfs_fs_mount+0x35/0x40 fs/xfs/xfs_super.c:1814 legacy_get_tree+0x108/0x220 fs/fs_context.c:661 vfs_get_tree+0x8e/0x390 fs/super.c:1476 do_new_mount fs/namespace.c:2791 [inline] do_mount+0x138c/0x1c00 fs/namespace.c:3111 ksys_mount+0xdb/0x150 fs/namespace.c:3320 __do_sys_mount fs/namespace.c:3334 [inline] __se_sys_mount fs/namespace.c:3331 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3331 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880693e2900 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 144 bytes inside of 1024-byte region [ffff8880693e2900, ffff8880693e2d00) The buggy address belongs to the page: page:ffffea0001a4f880 refcount:1 mapcount:0 mapping:ffff8880aa400c40 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00018ec788 ffffea0002473908 ffff8880aa400c40 raw: 0000000000000000 ffff8880693e2000 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880693e2880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880693e2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8880693e2980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880693e2a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880693e2a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This bug is generated by a bot. 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