Hello,
syzbot found the following crash on:
HEAD commit: acb1872577b3 Linux 4.18-rc7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14eb932c400000
kernel config: https://syzkaller.appspot.com/x/.config?x=2dc0cd7c2eefb46f
dashboard link: https://syzkaller.appspot.com/bug?extid=bd391451452fb0b93039
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: [email protected]
netlink: 'syz-executor5': attribute type 2 has an invalid length.
binder: 28577:28588 transaction failed 29189/-22, size 0-0 line 2852
==================================================================
BUG: KASAN: use-after-free in debug_spin_lock_before
kernel/locking/spinlock_debug.c:83 [inline]
BUG: KASAN: use-after-free in do_raw_spin_lock+0x1c0/0x200
kernel/locking/spinlock_debug.c:112
Read of size 4 at addr ffff880194d0ec6c by task syz-executor4/28583
CPU: 1 PID: 28583 Comm: syz-executor4 Not tainted 4.18.0-rc7+ #169
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_load4_noabort+0x14/0x20 mm/kasan/report.c:432
debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
do_raw_spin_lock+0x1c0/0x200 kernel/locking/spinlock_debug.c:112
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
_raw_spin_lock_bh+0x39/0x40 kernel/locking/spinlock.c:168
spin_lock_bh include/linux/spinlock.h:315 [inline]
vhost_transport_send_pkt+0x12e/0x380 drivers/vhost/vsock.c:223
virtio_transport_send_pkt_info+0x31d/0x460
net/vmw_vsock/virtio_transport_common.c:190
virtio_transport_connect+0x17c/0x220
net/vmw_vsock/virtio_transport_common.c:588
vsock_stream_connect+0x4fb/0xfc0 net/vmw_vsock/af_vsock.c:1197
__sys_connect+0x37d/0x4c0 net/socket.c:1673
__do_sys_connect net/socket.c:1684 [inline]
__se_sys_connect net/socket.c:1681 [inline]
__x64_sys_connect+0x73/0xb0 net/socket.c:1681
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: fd b4 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 b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fa4aee5bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007fa4aee5c6d4 RCX: 0000000000456a09
RDX: 0000000000000010 RSI: 0000000020000200 RDI: 0000000000000016
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004ca838 R14: 00000000004c25fb R15: 0000000000000000
Allocated by task 28583:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xc4/0xe0 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:573 [inline]
vhost_vsock_dev_open+0xa2/0x5a0 drivers/vhost/vsock.c:511
misc_open+0x3ca/0x560 drivers/char/misc.c:141
chrdev_open+0x25a/0x770 fs/char_dev.c:417
do_dentry_open+0x818/0xe40 fs/open.c:794
vfs_open+0x139/0x230 fs/open.c:908
do_last fs/namei.c:3399 [inline]
path_openat+0x174a/0x4e10 fs/namei.c:3540
do_filp_open+0x255/0x380 fs/namei.c:3574
do_sys_open+0x584/0x760 fs/open.c:1101
__do_sys_openat fs/open.c:1128 [inline]
__se_sys_openat fs/open.c:1122 [inline]
__x64_sys_openat+0x9d/0x100 fs/open.c:1122
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 28579:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3498 [inline]
kfree+0xd9/0x260 mm/slab.c:3813
kvfree+0x61/0x70 mm/util.c:442
vhost_vsock_free drivers/vhost/vsock.c:499 [inline]
vhost_vsock_dev_release+0x4fd/0x750 drivers/vhost/vsock.c:604
__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
tracehook_notify_resume include/linux/tracehook.h:192 [inline]
exit_to_usermode_loop+0x313/0x370 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 ffff880194d05f80
which belongs to the cache kmalloc-65536 of size 65536
The buggy address is located 36076 bytes inside of
65536-byte region [ffff880194d05f80, ffff880194d15f80)
The buggy address belongs to the page:
page:ffffea0006534000 count:1 mapcount:0 mapping:ffff8801dac02500 index:0x0
compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea0006599808 ffff8801dac01e48 ffff8801dac02500
raw: 0000000000000000 ffff880194d05f80 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff880194d0eb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff880194d0eb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff880194d0ec00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff880194d0ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff880194d0ed00: fb fb fb fb fb fb fb 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 [email protected].
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.
On Mon, Jul 30, 2018 at 11:15:03AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: acb1872577b3 Linux 4.18-rc7
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=14eb932c400000
> kernel config: https://syzkaller.appspot.com/x/.config?x=2dc0cd7c2eefb46f
> dashboard link: https://syzkaller.appspot.com/bug?extid=bd391451452fb0b93039
> 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: [email protected]
>
> netlink: 'syz-executor5': attribute type 2 has an invalid length.
> binder: 28577:28588 transaction failed 29189/-22, size 0-0 line 2852
> ==================================================================
> BUG: KASAN: use-after-free in debug_spin_lock_before
> kernel/locking/spinlock_debug.c:83 [inline]
> BUG: KASAN: use-after-free in do_raw_spin_lock+0x1c0/0x200
> kernel/locking/spinlock_debug.c:112
> Read of size 4 at addr ffff880194d0ec6c by task syz-executor4/28583
>
> CPU: 1 PID: 28583 Comm: syz-executor4 Not tainted 4.18.0-rc7+ #169
> 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_load4_noabort+0x14/0x20 mm/kasan/report.c:432
> debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
> do_raw_spin_lock+0x1c0/0x200 kernel/locking/spinlock_debug.c:112
> __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
> _raw_spin_lock_bh+0x39/0x40 kernel/locking/spinlock.c:168
> spin_lock_bh include/linux/spinlock.h:315 [inline]
> vhost_transport_send_pkt+0x12e/0x380 drivers/vhost/vsock.c:223
Thanks for the vsock fuzzing. This is a useful bug report.
It looks like vhost_vsock_get() needs to involve a reference count so
that vhost_vsock instances cannot be freed while something is still
using them.
The reproducer probably involves racing close() with connect().
I am looking into a fix.
Stefan
> virtio_transport_send_pkt_info+0x31d/0x460
> net/vmw_vsock/virtio_transport_common.c:190
> virtio_transport_connect+0x17c/0x220
> net/vmw_vsock/virtio_transport_common.c:588
> vsock_stream_connect+0x4fb/0xfc0 net/vmw_vsock/af_vsock.c:1197
> __sys_connect+0x37d/0x4c0 net/socket.c:1673
> __do_sys_connect net/socket.c:1684 [inline]
> __se_sys_connect net/socket.c:1681 [inline]
> __x64_sys_connect+0x73/0xb0 net/socket.c:1681
> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x456a09
> Code: fd b4 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 b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007fa4aee5bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
> RAX: ffffffffffffffda RBX: 00007fa4aee5c6d4 RCX: 0000000000456a09
> RDX: 0000000000000010 RSI: 0000000020000200 RDI: 0000000000000016
> RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
> R13: 00000000004ca838 R14: 00000000004c25fb R15: 0000000000000000
>
> Allocated by task 28583:
> save_stack+0x43/0xd0 mm/kasan/kasan.c:448
> set_track mm/kasan/kasan.c:460 [inline]
> kasan_kmalloc+0xc4/0xe0 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:573 [inline]
> vhost_vsock_dev_open+0xa2/0x5a0 drivers/vhost/vsock.c:511
> misc_open+0x3ca/0x560 drivers/char/misc.c:141
> chrdev_open+0x25a/0x770 fs/char_dev.c:417
> do_dentry_open+0x818/0xe40 fs/open.c:794
> vfs_open+0x139/0x230 fs/open.c:908
> do_last fs/namei.c:3399 [inline]
> path_openat+0x174a/0x4e10 fs/namei.c:3540
> do_filp_open+0x255/0x380 fs/namei.c:3574
> do_sys_open+0x584/0x760 fs/open.c:1101
> __do_sys_openat fs/open.c:1128 [inline]
> __se_sys_openat fs/open.c:1122 [inline]
> __x64_sys_openat+0x9d/0x100 fs/open.c:1122
> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> Freed by task 28579:
> save_stack+0x43/0xd0 mm/kasan/kasan.c:448
> set_track mm/kasan/kasan.c:460 [inline]
> __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
> kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
> __cache_free mm/slab.c:3498 [inline]
> kfree+0xd9/0x260 mm/slab.c:3813
> kvfree+0x61/0x70 mm/util.c:442
> vhost_vsock_free drivers/vhost/vsock.c:499 [inline]
> vhost_vsock_dev_release+0x4fd/0x750 drivers/vhost/vsock.c:604
> __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
> tracehook_notify_resume include/linux/tracehook.h:192 [inline]
> exit_to_usermode_loop+0x313/0x370 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 ffff880194d05f80
> which belongs to the cache kmalloc-65536 of size 65536
> The buggy address is located 36076 bytes inside of
> 65536-byte region [ffff880194d05f80, ffff880194d15f80)
> The buggy address belongs to the page:
> page:ffffea0006534000 count:1 mapcount:0 mapping:ffff8801dac02500 index:0x0
> compound_mapcount: 0
> flags: 0x2fffc0000008100(slab|head)
> raw: 02fffc0000008100 ffffea0006599808 ffff8801dac01e48 ffff8801dac02500
> raw: 0000000000000000 ffff880194d05f80 0000000100000001 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff880194d0eb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff880194d0eb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff880194d0ec00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff880194d0ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff880194d0ed00: fb fb fb fb fb fb fb 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 [email protected].
>
> syzbot will keep track of this bug report. See:
> https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
> syzbot.
On Tue, Jul 31, 2018 at 5:43 PM, Stefan Hajnoczi <[email protected]> wrote:
> On Mon, Jul 30, 2018 at 11:15:03AM -0700, syzbot wrote:
>> Hello,
>>
>> syzbot found the following crash on:
>>
>> HEAD commit: acb1872577b3 Linux 4.18-rc7
>> git tree: upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=14eb932c400000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=2dc0cd7c2eefb46f
>> dashboard link: https://syzkaller.appspot.com/bug?extid=bd391451452fb0b93039
>> 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: [email protected]
>>
>> netlink: 'syz-executor5': attribute type 2 has an invalid length.
>> binder: 28577:28588 transaction failed 29189/-22, size 0-0 line 2852
>> ==================================================================
>> BUG: KASAN: use-after-free in debug_spin_lock_before
>> kernel/locking/spinlock_debug.c:83 [inline]
>> BUG: KASAN: use-after-free in do_raw_spin_lock+0x1c0/0x200
>> kernel/locking/spinlock_debug.c:112
>> Read of size 4 at addr ffff880194d0ec6c by task syz-executor4/28583
>>
>> CPU: 1 PID: 28583 Comm: syz-executor4 Not tainted 4.18.0-rc7+ #169
>> 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_load4_noabort+0x14/0x20 mm/kasan/report.c:432
>> debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
>> do_raw_spin_lock+0x1c0/0x200 kernel/locking/spinlock_debug.c:112
>> __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
>> _raw_spin_lock_bh+0x39/0x40 kernel/locking/spinlock.c:168
>> spin_lock_bh include/linux/spinlock.h:315 [inline]
>> vhost_transport_send_pkt+0x12e/0x380 drivers/vhost/vsock.c:223
>
> Thanks for the vsock fuzzing. This is a useful bug report.
Thanks. But note that syzkaller descriptions for vsock were written by
people who have no idea what is vsock whatsoever:
https://github.com/google/syzkaller/blob/master/sys/linux/socket_vnet.txt
So most likely fuzzing is inefficient and does not test the most
interesting parts of vsock.
> It looks like vhost_vsock_get() needs to involve a reference count so
> that vhost_vsock instances cannot be freed while something is still
> using them.
>
> The reproducer probably involves racing close() with connect().
>
> I am looking into a fix.
>
> Stefan
>
>> virtio_transport_send_pkt_info+0x31d/0x460
>> net/vmw_vsock/virtio_transport_common.c:190
>> virtio_transport_connect+0x17c/0x220
>> net/vmw_vsock/virtio_transport_common.c:588
>> vsock_stream_connect+0x4fb/0xfc0 net/vmw_vsock/af_vsock.c:1197
>> __sys_connect+0x37d/0x4c0 net/socket.c:1673
>> __do_sys_connect net/socket.c:1684 [inline]
>> __se_sys_connect net/socket.c:1681 [inline]
>> __x64_sys_connect+0x73/0xb0 net/socket.c:1681
>> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>> RIP: 0033:0x456a09
>> Code: fd b4 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 b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
>> RSP: 002b:00007fa4aee5bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
>> RAX: ffffffffffffffda RBX: 00007fa4aee5c6d4 RCX: 0000000000456a09
>> RDX: 0000000000000010 RSI: 0000000020000200 RDI: 0000000000000016
>> RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
>> R13: 00000000004ca838 R14: 00000000004c25fb R15: 0000000000000000
>>
>> Allocated by task 28583:
>> save_stack+0x43/0xd0 mm/kasan/kasan.c:448
>> set_track mm/kasan/kasan.c:460 [inline]
>> kasan_kmalloc+0xc4/0xe0 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:573 [inline]
>> vhost_vsock_dev_open+0xa2/0x5a0 drivers/vhost/vsock.c:511
>> misc_open+0x3ca/0x560 drivers/char/misc.c:141
>> chrdev_open+0x25a/0x770 fs/char_dev.c:417
>> do_dentry_open+0x818/0xe40 fs/open.c:794
>> vfs_open+0x139/0x230 fs/open.c:908
>> do_last fs/namei.c:3399 [inline]
>> path_openat+0x174a/0x4e10 fs/namei.c:3540
>> do_filp_open+0x255/0x380 fs/namei.c:3574
>> do_sys_open+0x584/0x760 fs/open.c:1101
>> __do_sys_openat fs/open.c:1128 [inline]
>> __se_sys_openat fs/open.c:1122 [inline]
>> __x64_sys_openat+0x9d/0x100 fs/open.c:1122
>> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>>
>> Freed by task 28579:
>> save_stack+0x43/0xd0 mm/kasan/kasan.c:448
>> set_track mm/kasan/kasan.c:460 [inline]
>> __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
>> kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
>> __cache_free mm/slab.c:3498 [inline]
>> kfree+0xd9/0x260 mm/slab.c:3813
>> kvfree+0x61/0x70 mm/util.c:442
>> vhost_vsock_free drivers/vhost/vsock.c:499 [inline]
>> vhost_vsock_dev_release+0x4fd/0x750 drivers/vhost/vsock.c:604
>> __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
>> tracehook_notify_resume include/linux/tracehook.h:192 [inline]
>> exit_to_usermode_loop+0x313/0x370 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 ffff880194d05f80
>> which belongs to the cache kmalloc-65536 of size 65536
>> The buggy address is located 36076 bytes inside of
>> 65536-byte region [ffff880194d05f80, ffff880194d15f80)
>> The buggy address belongs to the page:
>> page:ffffea0006534000 count:1 mapcount:0 mapping:ffff8801dac02500 index:0x0
>> compound_mapcount: 0
>> flags: 0x2fffc0000008100(slab|head)
>> raw: 02fffc0000008100 ffffea0006599808 ffff8801dac01e48 ffff8801dac02500
>> raw: 0000000000000000 ffff880194d05f80 0000000100000001 0000000000000000
>> page dumped because: kasan: bad access detected
>>
>> Memory state around the buggy address:
>> ffff880194d0eb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff880194d0eb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> > ffff880194d0ec00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ^
>> ffff880194d0ec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>> ffff880194d0ed00: fb fb fb fb fb fb fb 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 [email protected].
>>
>> syzbot will keep track of this bug report. See:
>> https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
>> syzbot.
>
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syzbot has found a reproducer for the following crash on:
HEAD commit: 10dc890d4228 Merge tag 'pinctrl-v4.19-3' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11be7111400000
kernel config: https://syzkaller.appspot.com/x/.config?x=5fa12be50bca08d8
dashboard link: https://syzkaller.appspot.com/bug?extid=bd391451452fb0b93039
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=127cbf99400000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email protected]
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
hrtimer: interrupt took 32480 ns
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x37c2/0x4ec0
kernel/locking/lockdep.c:3290
Read of size 8 at addr ffff8801b192a110 by task syz-executor0/7102
CPU: 0 PID: 7102 Comm: syz-executor0 Not tainted 4.19.0-rc4+ #249
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+0x1c4/0x2b4 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_send_pkt+0x12e/0x380 drivers/vhost/vsock.c:223
virtio_transport_send_pkt_info+0x31d/0x460
net/vmw_vsock/virtio_transport_common.c:190
virtio_transport_connect+0x17c/0x220
net/vmw_vsock/virtio_transport_common.c:588
vsock_stream_connect+0x4ed/0xe40 net/vmw_vsock/af_vsock.c:1200
__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: 0033:0x457679
Code: 1d b4 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 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff9deebf38 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 000000000141d914 RCX: 0000000000457679
RDX: 0000000000000010 RSI: 0000000020000200 RDI: 0000000000000009
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cc658 R14: 00000000004bdcb3 R15: 0000000000000000
Allocated by task 7102:
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 7104:
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 ffff8801b1921400
which belongs to the cache kmalloc-65536 of size 65536
The buggy address is located 36112 bytes inside of
65536-byte region [ffff8801b1921400, ffff8801b1931400)
The buggy address belongs to the page:
page:ffffea0006c64800 count:1 mapcount:0 mapping:ffff8801da802500 index:0x0
compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea0006c64008 ffffea0006c69008 ffff8801da802500
raw: 0000000000000000 ffff8801b1921400 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8801b192a000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801b192a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8801b192a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8801b192a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801b192a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================