syzbot


KASAN: use-after-free Read in vhost_transport_cancel_pkt

Status: fixed on 2018/12/18 11:30
Subsystems: kvm net virt
[Documentation on labels]
Reported-by: syzbot+e3e074963495f92a89ed@syzkaller.appspotmail.com
Fix commit: 834e772c8db0 vhost/vsock: fix use-after-free in network stack callers
First crash: 2076d, last: 2026d
Discussions (7)
Title Replies (including bot) Last reply
[PATCH 4.19 000/118] 4.19.9-stable review 132 (132) 2018/12/17 08:30
[PATCH 4.14 00/67] 4.14.88-stable review 73 (73) 2018/12/12 18:50
[PATCH 4.9 00/51] 4.9.145-stable review 56 (56) 2018/12/12 18:49
[PULL] virtio/vhost: last minute fixes 1 (1) 2018/12/07 21:53
[PATCH net V2] vhost-vsock: fix use after free 6 (6) 2018/10/08 02:20
KASAN: use-after-free Read in vhost_transport_cancel_pkt 0 (2) 2018/10/06 15:47
[PATCH net] vhost-vsock: fix use after free 3 (3) 2018/09/27 12:21

Sample crash report:
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x37c2/0x4ec0 kernel/locking/lockdep.c:3290
Read of size 8 at addr ffff8801b05ac910 by task syz-executor0/6345

CPU: 0 PID: 6345 Comm: syz-executor0 Not tainted 4.19.0-rc8+ #71
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
 __lock_acquire+0x37c2/0x4ec0 kernel/locking/lockdep.c:3290
 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3900
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
 spin_lock_bh include/linux/spinlock.h:334 [inline]
 vhost_transport_cancel_pkt+0x15e/0x910 drivers/vhost/vsock.c:244
 vsock_transport_cancel_pkt net/vmw_vsock/af_vsock.c:1114 [inline]
 vsock_stream_connect+0x903/0xe40 net/vmw_vsock/af_vsock.c:1241
 __sys_connect+0x37d/0x4c0 net/socket.c:1664
 __do_sys_connect net/socket.c:1675 [inline]
 __se_sys_connect net/socket.c:1672 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1672
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fedaf41fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 0000000000000010 RSI: 0000000020000080 RDI: 0000000000000006
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fedaf4206d4
R13: 00000000004bdb1a R14: 00000000004cc670 R15: 00000000ffffffff

Allocated by task 6345:
 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
 __do_kmalloc_node mm/slab.c:3682 [inline]
 __kmalloc_node+0x47/0x70 mm/slab.c:3689
 kmalloc_node include/linux/slab.h:555 [inline]
 kvmalloc_node+0xb9/0xf0 mm/util.c:423
 kvmalloc include/linux/mm.h:577 [inline]
 vhost_vsock_dev_open+0xa2/0x5a0 drivers/vhost/vsock.c:511
 misc_open+0x3ca/0x560 drivers/char/misc.c:141
 chrdev_open+0x25a/0x710 fs/char_dev.c:417
 do_dentry_open+0x499/0x1250 fs/open.c:771
 vfs_open+0xa0/0xd0 fs/open.c:880
 do_last fs/namei.c:3418 [inline]
 path_openat+0x12bf/0x5160 fs/namei.c:3534
 do_filp_open+0x255/0x380 fs/namei.c:3564
 do_sys_open+0x568/0x700 fs/open.c:1063
 __do_sys_openat fs/open.c:1090 [inline]
 __se_sys_openat fs/open.c:1084 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1084
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 6343:
 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]
 kfree+0xcf/0x230 mm/slab.c:3813
 kvfree+0x61/0x70 mm/util.c:452
 vhost_vsock_free drivers/vhost/vsock.c:499 [inline]
 vhost_vsock_dev_release+0x4f4/0x720 drivers/vhost/vsock.c:604
 __fput+0x385/0xa30 fs/file_table.c:278
 ____fput+0x15/0x20 fs/file_table.c:309
 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801b05a3c00
 which belongs to the cache kmalloc-65536 of size 65536
The buggy address is located 36112 bytes inside of
 65536-byte region [ffff8801b05a3c00, ffff8801b05b3c00)
The buggy address belongs to the page:
page:ffffea0006c16800 count:1 mapcount:0 mapping:ffff8801da802500 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea0006c16008 ffffea0006c17008 ffff8801da802500
raw: 0000000000000000 ffff8801b05a3c00 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b05ac800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801b05ac880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801b05ac900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8801b05ac980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801b05aca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (17):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/10/21 10:35 upstream b0d04fb56b31 ecb386fe .config console log report syz ci-upstream-kasan-gce-smack-root
2018/10/21 03:19 upstream b0d04fb56b31 ecb386fe .config console log report syz ci-upstream-kasan-gce
2018/10/07 20:13 upstream fb1c592cf4c9 8b311eaf .config console log report syz ci-upstream-kasan-gce-smack-root
2018/10/06 16:18 upstream 091a1eaa0e30 8b311eaf .config console log report syz ci-upstream-kasan-gce
2018/10/06 16:17 upstream 091a1eaa0e30 8b311eaf .config console log report syz ci-upstream-kasan-gce-root
2018/10/06 15:46 upstream 091a1eaa0e30 8b311eaf .config console log report syz ci-upstream-kasan-gce-smack-root
2018/10/06 16:16 upstream 091a1eaa0e30 8b311eaf .config console log report syz ci-upstream-kasan-gce-386
2018/10/20 09:34 linux-next 8c60c36d0b8c ecb386fe .config console log report syz ci-upstream-linux-next-kasan-gce-root
2018/11/09 17:24 upstream 24ccea7e102d 8fd01d3a .config console log report ci-upstream-kasan-gce-smack-root
2018/10/23 16:52 upstream 58a022870787 24fa2ad8 .config console log report ci-upstream-kasan-gce-smack-root
2018/10/18 03:11 upstream c343db455eb3 b2695b95 .config console log report ci-upstream-kasan-gce-root
2018/10/08 10:37 upstream 0238df646e62 8b311eaf .config console log report ci-upstream-kasan-gce-root
2018/10/07 23:14 upstream fb1c592cf4c9 8b311eaf .config console log report ci-upstream-kasan-gce
2018/10/07 19:04 upstream fb1c592cf4c9 8b311eaf .config console log report ci-upstream-kasan-gce
2018/10/06 15:28 upstream 091a1eaa0e30 8b311eaf .config console log report ci-upstream-kasan-gce-smack-root
2018/09/20 04:07 upstream 4ca719a338d5 7f125108 .config console log report ci-upstream-kasan-gce-386
2018/10/20 08:45 linux-next 8c60c36d0b8c ecb386fe .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.