From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Pismenny Subject: Re: KASAN: use-after-free Write in tls_push_record (2) Date: Thu, 12 Jul 2018 06:44:55 -0400 Message-ID: References: <000000000000ae783b0570c2ba09@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit To: syzbot , aviadye@mellanox.com, davejwatson@fb.com, davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Return-path: In-Reply-To: <000000000000ae783b0570c2ba09@google.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org It seems to me that the crash here is due to write_space being called after the close system call. Maybe the correct solution is to move the TX software state to be released in sk_destruct. As we already do for the device state (see tls_device.c). Is anyone looking into this one? On 7/11/2018 8:49 PM, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit:    1e09177acae3 Merge tag 'mips_fixes_4.18_3' of > git://git.ke.. > git tree:       upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=128903b2400000 > kernel config:  https://syzkaller.appspot.com/x/.config?x=25856fac4e580aa7 > dashboard link: > https://syzkaller.appspot.com/bug?extid=6c4e6ecbf9a2797be67c > compiler:       gcc (GCC) 8.0.1 20180413 (experimental) > syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=12312678400000 > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13ef76c2400000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+6c4e6ecbf9a2797be67c@syzkaller.appspotmail.com > > RDX: 00000000fffffdef RSI: 00000000200005c0 RDI: 0000000000000003 > RBP: 00000000006cb018 R08: 0000000020000000 R09: 000000000000001c > R10: 0000000000000040 R11: 0000000000000212 R12: 0000000000000005 > R13: ffffffffffffffff R14: 0000000000000000 R15: 0000000000000000 > ================================================================== > BUG: KASAN: use-after-free in tls_fill_prepend include/net/tls.h:339 > [inline] > BUG: KASAN: use-after-free in tls_push_record+0x1091/0x1400 > net/tls/tls_sw.c:239 > Write of size 1 at addr ffff8801ae430000 by task syz-executor589/4567 > > CPU: 0 PID: 4567 Comm: syz-executor589 Not tainted 4.18.0-rc4+ #141 > 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+0x1c9/0x2b4 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_store1_noabort+0x17/0x20 mm/kasan/report.c:435 >  tls_fill_prepend include/net/tls.h:339 [inline] >  tls_push_record+0x1091/0x1400 net/tls/tls_sw.c:239 >  tls_sw_push_pending_record+0x22/0x30 net/tls/tls_sw.c:276 >  tls_handle_open_record net/tls/tls_main.c:164 [inline] >  tls_sk_proto_close+0x74c/0xae0 net/tls/tls_main.c:264 >  inet_release+0x104/0x1f0 net/ipv4/af_inet.c:427 >  inet6_release+0x50/0x70 net/ipv6/af_inet6.c:459 >  __sock_release+0xd7/0x260 net/socket.c:599 >  sock_close+0x19/0x20 net/socket.c:1150 >  __fput+0x355/0x8b0 fs/file_table.c:209 >  ____fput+0x15/0x20 fs/file_table.c:243 >  task_work_run+0x1ec/0x2a0 kernel/task_work.c:113 >  exit_task_work include/linux/task_work.h:22 [inline] >  do_exit+0x1b08/0x2750 kernel/exit.c:865 >  do_group_exit+0x177/0x440 kernel/exit.c:968 >  __do_sys_exit_group kernel/exit.c:979 [inline] >  __se_sys_exit_group kernel/exit.c:977 [inline] >  __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:977 >  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 >  entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x43f358 > Code: Bad RIP value. > RSP: 002b:00007fff51750198 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043f358 > RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 > RBP: 00000000004bf448 R08: 00000000000000e7 R09: ffffffffffffffd0 > R10: 0000000000000040 R11: 0000000000000246 R12: 0000000000000001 > R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 > > The buggy address belongs to the page: > page:ffffea0006b90c00 count:0 mapcount:-128 mapping:0000000000000000 > index:0x0 > flags: 0x2fffc0000000000() > raw: 02fffc0000000000 ffffea0006b96408 ffff88021fffac18 0000000000000000 > raw: 0000000000000000 0000000000000003 00000000ffffff7f 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: >  ffff8801ae42ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >  ffff8801ae42ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >> ffff8801ae430000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >                    ^ >  ffff8801ae430080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >  ffff8801ae430100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ================================================================== > > > --- > 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