From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 Date: Sat, 09 Jun 2018 08:36:01 -0700 In-Reply-To: <000000000000973c2c056e0ecddd@google.com> Message-ID: <00000000000015df96056e374691@google.com> Subject: Re: general protection fault in __vfs_write From: syzbot To: alexei.starovoitov@gmail.com, ast@kernel.org, daniel@iogearbox.net, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk, willy@infradead.org Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: netdev-owner@vger.kernel.org List-ID: syzbot has found a reproducer for the following crash on: HEAD commit: 3a979e8c07e3 Merge tag 'mailbox-v4.18' of git://git.linaro.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=11e0c81f800000 kernel config: https://syzkaller.appspot.com/x/.config?x=412e35656a3f7c09 dashboard link: https://syzkaller.appspot.com/bug?extid=7ade6c94abb2774c0fee compiler: gcc (GCC) 8.0.1 20180413 (experimental) syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=1665abf7800000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+7ade6c94abb2774c0fee@syzkaller.appspotmail.com IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready 8021q: adding VLAN 0 to HW filter on device team0 8021q: adding VLAN 0 to HW filter on device team0 bpfilter: read fail -512 kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN CPU: 0 PID: 4546 Comm: syz-executor6 Not tainted 4.17.0+ #83 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:file_write_hint include/linux/fs.h:1932 [inline] RIP: 0010:init_sync_kiocb include/linux/fs.h:1942 [inline] RIP: 0010:new_sync_write fs/read_write.c:470 [inline] RIP: 0010:__vfs_write+0x4a6/0x960 fs/read_write.c:487 Code: c1 ea 03 80 3c 02 00 0f 85 1b 04 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 20 49 8d bc 24 c8 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e ec 02 00 00 41 8b 84 24 c8 00 RSP: 0018:ffff8801ae407850 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8801cd88f580 RCX: ffffffff81c0d6fb RDX: 0000000000000019 RSI: ffffffff81c0d70a RDI: 00000000000000c8 RBP: ffff8801ae4079c8 R08: ffff8801d88ee680 R09: fffffbfff130c5d9 R10: ffff8801ae407a10 R11: ffffffff89862ecb R12: 0000000000000000 R13: ffff8801ae4079a0 R14: 0000000000000000 R15: ffff8801ae407a88 FS: 000000000102f940(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5f52ac0518 CR3: 00000001d8d8a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __kernel_write+0x10c/0x380 fs/read_write.c:506 __bpfilter_process_sockopt+0x1d8/0x35b net/bpfilter/bpfilter_kern.c:66 bpfilter_mbox_request+0x4d/0xb0 net/ipv4/bpfilter/sockopt.c:25 bpfilter_ip_get_sockopt+0x6b/0x90 net/ipv4/bpfilter/sockopt.c:42 ip_getsockopt+0x238/0x2a0 net/ipv4/ip_sockglue.c:1563 tcp_getsockopt+0x93/0xe0 net/ipv4/tcp.c:3532 sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:3012 __sys_getsockopt+0x1a5/0x370 net/socket.c:1972 __do_sys_getsockopt net/socket.c:1983 [inline] __se_sys_getsockopt net/socket.c:1980 [inline] __x64_sys_getsockopt+0xbe/0x150 net/socket.c:1980 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4584ea Code: b8 34 01 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 1d 8f fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 fa 8e fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:0000000000a3e328 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 0000000000a3e350 RCX: 00000000004584ea RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000706f20 R08: 0000000000a3e34c R09: 0000000000004000 R10: 0000000000a3e350 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000706860 Modules linked in: Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace 9a583fc95516c106 ]--- RIP: 0010:file_write_hint include/linux/fs.h:1932 [inline] RIP: 0010:init_sync_kiocb include/linux/fs.h:1942 [inline] RIP: 0010:new_sync_write fs/read_write.c:470 [inline] RIP: 0010:__vfs_write+0x4a6/0x960 fs/read_write.c:487 Code: c1 ea 03 80 3c 02 00 0f 85 1b 04 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 20 49 8d bc 24 c8 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e ec 02 00 00 41 8b 84 24 c8 00 RSP: 0018:ffff8801ae407850 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8801cd88f580 RCX: ffffffff81c0d6fb RDX: 0000000000000019 RSI: ffffffff81c0d70a RDI: 00000000000000c8 RBP: ffff8801ae4079c8 R08: ffff8801d88ee680 R09: fffffbfff130c5d9 R10: ffff8801ae407a10 R11: ffffffff89862ecb R12: 0000000000000000 R13: ffff8801ae4079a0 R14: 0000000000000000 R15: ffff8801ae407a88 FS: 000000000102f940(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5f52ac0518 CR3: 00000001d8d8a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400