From mboxrd@z Thu Jan 1 00:00:00 1970 From: syzbot Subject: KASAN: slab-out-of-bounds Read in build_segment_manager Date: Fri, 20 Apr 2018 09:55:02 -0700 Message-ID: <00000000000092512b056a4a8c76@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed"; DelSp="yes" Content-Transfer-Encoding: 7bit Return-path: Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from <3ZhvaWgkbAOEVbcNDOOHUDSSLG.JRRJOHXVHUFRQWHQW.FRP@M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com>) id 1f9ZJV-0001Nn-Lt for linux-f2fs-devel@lists.sourceforge.net; Fri, 20 Apr 2018 16:55:09 +0000 Received: from mail-io0-f199.google.com ([209.85.223.199]) by sfi-mx-4.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) id 1f9ZJT-0080xr-R4 for linux-f2fs-devel@lists.sourceforge.net; Fri, 20 Apr 2018 16:55:09 +0000 Received: by mail-io0-f199.google.com with SMTP id o17-v6so7679711iob.12 for ; Fri, 20 Apr 2018 09:55:07 -0700 (PDT) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: jaegeuk@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, yuchao0@huawei.com Hello, syzbot hit the following crash on upstream commit 87ef12027b9b1dd0e0b12cf311fbcb19f9d92539 (Wed Apr 18 19:48:17 2018 +0000) Merge tag 'ceph-for-4.17-rc2' of git://github.com/ceph/ceph-client syzbot dashboard link: https://syzkaller.appspot.com/bug?extid=0a725420475916460f12 C reproducer: https://syzkaller.appspot.com/x/repro.c?id=4726415475867648 syzkaller reproducer: https://syzkaller.appspot.com/x/repro.syz?id=5230577728880640 Raw console output: https://syzkaller.appspot.com/x/log.txt?id=4759744422084608 Kernel config: https://syzkaller.appspot.com/x/.config?id=1808800213120130118 compiler: gcc (GCC) 8.0.1 20180413 (experimental) IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+0a725420475916460f12@syzkaller.appspotmail.com It will help syzbot understand when the bug is fixed. See footer for details. If you forward the report, please keep this part and the footer. F2FS-fs (loop0): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock F2FS-fs (loop0): invalid crc value ================================================================== BUG: KASAN: slab-out-of-bounds in build_sit_entries fs/f2fs/segment.c:3653 [inline] BUG: KASAN: slab-out-of-bounds in build_segment_manager+0xb92d/0xbf70 fs/f2fs/segment.c:3852 Read of size 4 at addr ffff8801ac7b66e0 by task syzkaller806281/4519 CPU: 0 PID: 4519 Comm: syzkaller806281 Not tainted 4.17.0-rc1+ #8 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_load4_noabort+0x14/0x20 mm/kasan/report.c:432 build_sit_entries fs/f2fs/segment.c:3653 [inline] build_segment_manager+0xb92d/0xbf70 fs/f2fs/segment.c:3852 f2fs_fill_super+0x4095/0x7bf0 fs/f2fs/super.c:2803 mount_bdev+0x30c/0x3e0 fs/super.c:1165 f2fs_mount+0x34/0x40 fs/f2fs/super.c:3020 mount_fs+0xae/0x328 fs/super.c:1268 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:2517 [inline] do_mount+0x564/0x3070 fs/namespace.c:2847 ksys_mount+0x12d/0x140 fs/namespace.c:3063 __do_sys_mount fs/namespace.c:3077 [inline] __se_sys_mount fs/namespace.c:3074 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3074 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4477ca RSP: 002b:00007fff69213888 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000b70 RCX: 00000000004477ca RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fff692138c0 RBP: 0000000000000064 R08: 0000000020016600 R09: 000000000000000a R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000064 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 2845: 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 getname_flags+0xd0/0x5a0 fs/namei.c:140 getname+0x19/0x20 fs/namei.c:211 do_sys_open+0x39a/0x740 fs/open.c:1087 __do_sys_open fs/open.c:1111 [inline] __se_sys_open fs/open.c:1106 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1106 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 2845: 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 putname+0xf2/0x130 fs/namei.c:261 do_sys_open+0x554/0x740 fs/open.c:1102 __do_sys_open fs/open.c:1111 [inline] __se_sys_open fs/open.c:1106 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1106 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801ac7b69c0 which belongs to the cache names_cache of size 4096 The buggy address is located 736 bytes to the left of 4096-byte region [ffff8801ac7b69c0, ffff8801ac7b79c0) The buggy address belongs to the page: page:ffffea0006b1ed80 count:1 mapcount:0 mapping:ffff8801ac7b69c0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801ac7b69c0 0000000000000000 0000000100000001 raw: ffffea0006b1f7a0 ffffea0006b1eea0 ffff8801da988dc0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801ac7b6580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801ac7b6600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801ac7b6680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801ac7b6700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801ac7b6780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== --- This bug is generated by a dumb bot. 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