From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: KASAN: use-after-free Read in do_exit Date: Wed, 24 Oct 2018 08:54:52 -0500 Message-ID: <87k1m7phzn.fsf@xmission.com> References: <000000000000f6512e0578f70944@google.com> Mime-Version: 1.0 Content-Type: text/plain Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux@dominikbrodowski.net, mark.rutland@arm.com, paulmck@linux.vnet.ibm.com, sudipm.mukherjee@gmail.com, syzkaller-bugs@googlegroups.com, , Boris Pismenny , Daniel Borkmann , Eric Dumazet , Ilya Lesokhin , Aviad Yehezkel To: syzbot Return-path: In-Reply-To: <000000000000f6512e0578f70944@google.com> (syzbot's message of "Wed, 24 Oct 2018 03:35:02 -0700") Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Adding netdev and some likely suspects as this appears to happen in tls_sk_proto_close. syzbot writes: > Hello, > > syzbot found the following crash on: > > HEAD commit: 58a022870787 Merge tag 'acpi-4.20-rc1' of git://git.kernel.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=12a0f939400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=414a8e66ba2c6789 > dashboard link: https://syzkaller.appspot.com/bug?extid=71a06dcf7e167c30ab9d > compiler: gcc (GCC) 8.0.1 20180413 (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+71a06dcf7e167c30ab9d@syzkaller.appspotmail.com > > TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. > Check SNMP counters. > input: syz1 as /devices/virtual/input/input1084 > netlink: 20 bytes leftover after parsing attributes in process `syz-executor2'. > kasan: CONFIG_KASAN_INLINE enabled > ================================================================== > BUG: KASAN: use-after-free in stack_not_used > include/linux/sched/task_stack.h:101 [inline] > BUG: KASAN: use-after-free in check_stack_usage kernel/exit.c:748 [inline] > BUG: KASAN: use-after-free in do_exit+0x2196/0x26d0 kernel/exit.c:916 > Read of size 8 at addr ffff8801c2b90008 by task blkid/5862 > > CPU: 1 PID: 5862 Comm: blkid Not tainted 4.19.0+ #299 > 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+0x1c4/0x2b6 lib/dump_stack.c:113 > print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > stack_not_used include/linux/sched/task_stack.h:101 [inline] > check_stack_usage kernel/exit.c:748 [inline] > do_exit+0x2196/0x26d0 kernel/exit.c:916 > kasan: GPF could be caused by NULL-ptr deref or user memory access > general protection fault: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 5797 Comm: syz-executor4 Not tainted 4.19.0+ #299 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google > 01/01/2011 > RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] > RIP: 0010:compound_head include/linux/page-flags.h:142 [inline] > RIP: 0010:put_page include/linux/mm.h:931 [inline] > RIP: 0010:tls_sk_proto_close+0x419/0xbb0 net/tls/tls_main.c:277 > Code: 8d e8 fe ff ff 48 89 85 f0 fe ff ff e8 b0 55 db fa 48 8b 85 f0 fe ff ff 49 > 83 e5 fc 49 8d 7d 08 c6 00 00 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 ad 06 > 00 00 48 8b 85 f0 fe ff ff 4d 8b 75 08 > RSP: 0018:ffff88018c2e6f70 EFLAGS: 00010202 > RAX: 0000000000000001 RBX: ffff88018566ae40 RCX: ffffffff86a36050 > RDX: 0000000000000000 RSI: ffffffff86a35e10 RDI: 0000000000000008 > RBP: ffff88018c2e70d0 R08: ffff880182d0c580 R09: 0000000000000006 > R10: 0000000000000000 R11: ffff880182d0c580 R12: dffffc0000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88018ba82740 > FS: 00007f2e39ea9700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000001b32334000 CR3: 00000001ccbdb000 CR4: 00000000001426f0 > Call Trace: > inet_release+0x104/0x1f0 net/ipv4/af_inet.c:428 > inet6_release+0x50/0x70 net/ipv6/af_inet6.c:457 > __sock_release+0xd7/0x250 net/socket.c:579 > sock_close+0x19/0x20 net/socket.c:1141 > __fput+0x385/0xa30 fs/file_table.c:278 > do_group_exit+0x177/0x440 kernel/exit.c:970 > ____fput+0x15/0x20 fs/file_table.c:309 > task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 > __do_sys_exit_group kernel/exit.c:981 [inline] > __se_sys_exit_group kernel/exit.c:979 [inline] > __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > exit_task_work include/linux/task_work.h:22 [inline] > do_exit+0x1ad6/0x26d0 kernel/exit.c:867 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x7f564809d1e8 > Code: Bad RIP value. > RSP: 002b:00007ffd77478cc8 EFLAGS: 00000246 > ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f564809d1e8 > RDX: 0000000000000002 RSI: 000000000000003c RDI: 0000000000000002 > RBP: 00007f5648372840 R08: 00000000000000e7 R09: ffffffffffffffa8 > R10: 00007f5648378740 R11: 0000000000000246 R12: 00007f5648372840 > R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 > > Allocated by task 5279: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 > kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 > kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554 > kmem_cache_zalloc include/linux/slab.h:697 [inline] > locks_alloc_lock+0x8e/0x270 fs/locks.c:303 > fcntl_setlk+0xc8/0xfb0 fs/locks.c:2246 > do_fcntl+0xa6f/0x1500 fs/fcntl.c:370 > __do_sys_fcntl fs/fcntl.c:463 [inline] > __se_sys_fcntl fs/fcntl.c:448 [inline] > __x64_sys_fcntl+0x177/0x1f0 fs/fcntl.c:448 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 5279: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > __kasan_slab_free+0x102/0x150 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+0x83/0x290 mm/slab.c:3756 > locks_free_lock+0x209/0x340 fs/locks.c:339 > fcntl_setlk+0x79f/0xfb0 fs/locks.c:2323 > do_fcntl+0xa6f/0x1500 fs/fcntl.c:370 > __do_sys_fcntl fs/fcntl.c:463 [inline] > __se_sys_fcntl fs/fcntl.c:448 [inline] > __x64_sys_fcntl+0x177/0x1f0 fs/fcntl.c:448 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8801c2b90000 > which belongs to the cache file_lock_cache of size 248 > The buggy address is located 8 bytes inside of > 248-byte region [ffff8801c2b90000, ffff8801c2b900f8) > The buggy address belongs to the page: > do_group_exit+0x177/0x440 kernel/exit.c:970 > page:ffffea00070ae400 count:1 mapcount:0 mapping:ffff8801d9bf5b00 index:0x0 > get_signal+0x8b0/0x1980 kernel/signal.c:2513 > flags: 0x2fffc0000000100(slab) > raw: 02fffc0000000100 ffffea000709e388 ffffea0006039548 ffff8801d9bf5b00 > raw: 0000000000000000 ffff8801c2b90000 000000010000000d 0000000000000000 > page dumped because: kasan: bad access detected > do_signal+0x9c/0x21e0 arch/x86/kernel/signal.c:816 > > Memory state around the buggy address: > ffff8801c2b8ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffff8801c2b8ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >> ffff8801c2b90000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8801c2b90080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc > ffff8801c2b90100: fc fc fc fc fc fc fc 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.