syzbot


KASAN: use-after-free Read in __list_add_valid (3)

Status: fixed on 2018/02/04 11:35
Subsystems: kvm net virt
[Documentation on labels]
Reported-by: syzbot+fbbedb95ed1d1e95781e@syzkaller.appspotmail.com
Fix commit: 4cd879515d68 vhost_net: stop device during reset owner
First crash: 2332d, last: 2324d
Discussions (2)
Title Replies (including bot) Last reply
Re: KASAN: use-after-free Read in __list_add_valid (3) 1 (1) 2018/02/02 23:55
Re: KASAN: use-after-free Read in __list_add_valid (3) 1 (1) 2018/01/25 10:02
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in __list_add_valid (5) rdma C 16 2264d 2271d 11/28 fixed on 2019/02/21 08:43
upstream KASAN: use-after-free Read in __list_add_valid (2) net 1 2390d 2390d 0/28 closed as invalid on 2018/01/19 22:57
upstream KASAN: use-after-free Read in __list_add_valid (4) rdma C 61 2273d 2288d 0/28 closed as dup on 2018/03/22 15:30
upstream KASAN: use-after-free Read in __list_add_valid syz 26 2427d 2474d 3/28 fixed on 2017/10/24 22:03

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __list_add_valid+0xb1/0xd0 lib/list_debug.c:23
Read of size 8 at addr ffff8801bfccdfd0 by task syz-executor3/8573

CPU: 1 PID: 8573 Comm: syz-executor3 Not tainted 4.15.0+ #288
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 __list_add_valid+0xb1/0xd0 lib/list_debug.c:23
 __list_add include/linux/list.h:60 [inline]
 list_add include/linux/list.h:79 [inline]
 __add_wait_queue include/linux/wait.h:156 [inline]
 add_wait_queue+0xcf/0x290 kernel/sched/wait.c:30
 vhost_poll_func+0x3d/0x50 drivers/vhost/vhost.c:165
 poll_wait include/linux/poll.h:46 [inline]
 eventfd_poll+0xe8/0x1f0 fs/eventfd.c:123
 vhost_poll_start+0x93/0x1c0 drivers/vhost/vhost.c:212
 vhost_vring_ioctl+0xe28/0x19b0 drivers/vhost/vhost.c:1560
 vhost_net_ioctl+0x9df/0x1910 drivers/vhost/net.c:1320
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x453299
RSP: 002b:00007f391f4f0c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000071bf58 RCX: 0000000000453299
RDX: 00000000208ffff8 RSI: 000000004008af20 RDI: 0000000000000013
RBP: 0000000000000342 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f3ed0
R13: 00000000ffffffff R14: 00007f391f4f16d4 R15: 0000000000000002

Allocated by task 8567:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 __do_kmalloc_node mm/slab.c:3672 [inline]
 __kmalloc_node+0x47/0x70 mm/slab.c:3679
 kmalloc_node include/linux/slab.h:541 [inline]
 kvmalloc_node+0x64/0xd0 mm/util.c:397
 kvmalloc include/linux/mm.h:541 [inline]
 vhost_net_open+0x27/0x670 drivers/vhost/net.c:902
 misc_open+0x382/0x500 drivers/char/misc.c:154
 chrdev_open+0x257/0x730 fs/char_dev.c:417
 do_dentry_open+0x667/0xd40 fs/open.c:752
 vfs_open+0x107/0x220 fs/open.c:866
 do_last fs/namei.c:3397 [inline]
 path_openat+0x1151/0x3530 fs/namei.c:3537
 do_filp_open+0x25b/0x3b0 fs/namei.c:3572
 do_sys_open+0x502/0x6d0 fs/open.c:1059
 SYSC_openat fs/open.c:1086 [inline]
 SyS_openat+0x30/0x40 fs/open.c:1080
 entry_SYSCALL_64_fastpath+0x29/0xa0

Freed by task 8567:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3488 [inline]
 kfree+0xd6/0x260 mm/slab.c:3803
 kvfree+0x36/0x60 mm/util.c:416
 vhost_net_release+0x159/0x190 drivers/vhost/net.c:1012
 __fput+0x327/0x7e0 fs/file_table.c:210
 ____fput+0x15/0x20 fs/file_table.c:244
 task_work_run+0x199/0x270 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
 entry_SYSCALL_64_fastpath+0x9e/0xa0

The buggy address belongs to the object at ffff8801bfccdd40
 which belongs to the cache kmalloc-65536 of size 65536
The buggy address is located 656 bytes inside of
 65536-byte region [ffff8801bfccdd40, ffff8801bfcddd40)
The buggy address belongs to the page:
page:ffffea0006ff3000 count:1 mapcount:0 mapping:ffff8801bfccdd40 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801bfccdd40 0000000000000000 0000000100000001
raw: ffffea00071f7820 ffffea00076d1820 ffff8801db002500 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801bfccde80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801bfccdf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801bfccdf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff8801bfcce000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801bfcce080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (16):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/01/31 14:18 upstream 3da90b159b14 02553e22 .config console log report ci-upstream-kasan-gce
2018/01/30 11:45 upstream 6304672b7f0a 08d47756 .config console log report ci-upstream-kasan-gce
2018/01/29 02:29 upstream 24b1cccf9229 08d47756 .config console log report ci-upstream-kasan-gce
2018/01/26 19:44 upstream 993ca2068b04 1d18b112 .config console log report ci-upstream-kasan-gce
2018/01/26 16:20 upstream 993ca2068b04 1d18b112 .config console log report ci-upstream-kasan-gce
2018/01/25 17:43 upstream 5b7d27967dab 6b2a715e .config console log report ci-upstream-kasan-gce
2018/01/24 13:48 upstream 1f07476ec143 a5b7566c .config console log report ci-upstream-kasan-gce
2018/01/24 08:55 upstream 1f07476ec143 a5b7566c .config console log report ci-upstream-kasan-gce
2018/01/24 07:58 upstream 1f07476ec143 a5b7566c .config console log report ci-upstream-kasan-gce
2018/01/24 07:28 upstream 1f07476ec143 a5b7566c .config console log report ci-upstream-kasan-gce
2018/01/23 11:03 upstream a0ec1ded22e6 228e3d95 .config console log report ci-upstream-kasan-gce
2018/02/01 00:44 upstream 3da90b159b14 02553e22 .config console log report ci-upstream-kasan-gce-386
2018/01/30 16:34 upstream 6304672b7f0a a899be78 .config console log report ci-upstream-kasan-gce-386
2018/01/30 09:12 upstream 6304672b7f0a 08d47756 .config console log report ci-upstream-kasan-gce-386
2018/01/27 07:36 upstream c4e0ca7fa241 1d18b112 .config console log report ci-upstream-kasan-gce-386
2018/01/25 06:46 upstream 5132ede0fe80 866f1102 .config console log report ci-upstream-kasan-gce-386
* Struck through repros no longer work on HEAD.