Re: net/kcm: use-after-free in kcm_wq

2017-03-23 Thread Dmitry Vyukov 
On Fri, Mar 3, 2017 at 9:03 PM, Cong Wang  wrote:
> On Fri, Mar 3, 2017 at 2:11 AM, Dmitry Vyukov  wrote:
>> Also like this one:
>>
>> ==
>> BUG: KASAN: use-after-free in atomic_long_read
>> include/linux/compiler.h:254 [inline] at addr 8800538aba60
>> BUG: KASAN: use-after-free in get_work_pool+0x2f2/0x340
>> kernel/workqueue.c:709 at addr 8800538aba60
>> Read of size 8 by task syz-executor6/7965
>> CPU: 2 PID: 7965 Comm: syz-executor6 Not tainted 4.10.0+ #248
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> Call Trace:
>>  __dump_stack lib/dump_stack.c:15 [inline]
>>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>>  print_address_description mm/kasan/report.c:204 [inline]
>>  kasan_report_error mm/kasan/report.c:288 [inline]
>>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>>  kasan_report mm/kasan/report.c:331 [inline]
>>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>>  atomic_long_read include/linux/compiler.h:254 [inline]
>>  get_work_pool+0x2f2/0x340 kernel/workqueue.c:709
>>  __queue_work+0x2b3/0x1210 kernel/workqueue.c:1401
>>  queue_work_on+0x2e9/0x330 kernel/workqueue.c:1486
>>  queue_work include/linux/workqueue.h:487 [inline]
>>  strp_check_rcv+0x25/0x30 net/strparser/strparser.c:494
>
>
> It is not kcm_wq, it is strp_wq, and the work struct is strp->rx_work
> which lives in struct kcm_psock. The work is cancelled by strp_done(),
> it seems get queued again after strp_done()...


on 093b995e3b55a0ae0670226ddfcb05bfbf0099ae:

==
BUG: KASAN: use-after-free in worker_thread+0x1024/0x1340
kernel/workqueue.c:2229 at addr 88006d164ae0
Read of size 8 by task kworker/u8:3/25139
CPU: 2 PID: 25139 Comm: kworker/u8:3 Not tainted 4.11.0-rc3+ #364
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x1b8/0x28d lib/dump_stack.c:52
 kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
 print_address_description mm/kasan/report.c:210 [inline]
 kasan_report_error mm/kasan/report.c:294 [inline]
 kasan_report.part.2+0x1be/0x480 mm/kasan/report.c:316
 kasan_report mm/kasan/report.c:337 [inline]
 __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:337
 worker_thread+0x1024/0x1340 kernel/workqueue.c:2229
 kthread+0x359/0x420 kernel/kthread.c:229
 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
Object at 88006d1649c0, in cache kcm_psock_cache size: 616
Allocated:
PID = 25123
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:517
 set_track mm/kasan/kasan.c:529 [inline]
 kasan_kmalloc+0xbc/0xf0 mm/kasan/kasan.c:620
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:559
 kmem_cache_alloc+0x110/0x720 mm/slab.c:3572
 kmem_cache_zalloc include/linux/slab.h:653 [inline]
 kcm_attach net/kcm/kcmsock.c:1386 [inline]
 kcm_attach_ioctl net/kcm/kcmsock.c:1457 [inline]
 kcm_ioctl+0x2bc/0x17e0 net/kcm/kcmsock.c:1692
 sock_do_ioctl+0x65/0xb0 net/socket.c:895
 sock_ioctl+0x2c2/0x440 net/socket.c:993
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1af/0x16d0 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xc2
Freed:
PID = 25139
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:517
 set_track mm/kasan/kasan.c:529 [inline]
 kasan_slab_free+0x81/0xc0 mm/kasan/kasan.c:593
 __cache_free mm/slab.c:3514 [inline]
 kmem_cache_free+0x71/0x240 mm/slab.c:3774
 unreserve_psock+0x5d4/0x7b0 net/kcm/kcmsock.c:547
 kcm_write_msgs+0xba6/0x1ba0 net/kcm/kcmsock.c:590
 kcm_tx_work+0x32/0x1f0 net/kcm/kcmsock.c:731
 process_one_work+0xb20/0x1b40 kernel/workqueue.c:2097
 worker_thread+0x1b4/0x1340 kernel/workqueue.c:2231
 kthread+0x359/0x420 kernel/kthread.c:229
 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
Memory state around the buggy address:
 88006d164980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 88006d164a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>88006d164a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
   ^
 88006d164b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 88006d164b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==

Re: net/kcm: use-after-free in kcm_wq

2017-03-23 Thread Dmitry Vyukov 
On Fri, Mar 3, 2017 at 9:03 PM, Cong Wang  wrote:
> On Fri, Mar 3, 2017 at 2:11 AM, Dmitry Vyukov  wrote:
>> Also like this one:
>>
>> ==
>> BUG: KASAN: use-after-free in atomic_long_read
>> include/linux/compiler.h:254 [inline] at addr 8800538aba60
>> BUG: KASAN: use-after-free in get_work_pool+0x2f2/0x340
>> kernel/workqueue.c:709 at addr 8800538aba60
>> Read of size 8 by task syz-executor6/7965
>> CPU: 2 PID: 7965 Comm: syz-executor6 Not tainted 4.10.0+ #248
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> Call Trace:
>>  __dump_stack lib/dump_stack.c:15 [inline]
>>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>>  print_address_description mm/kasan/report.c:204 [inline]
>>  kasan_report_error mm/kasan/report.c:288 [inline]
>>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>>  kasan_report mm/kasan/report.c:331 [inline]
>>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>>  atomic_long_read include/linux/compiler.h:254 [inline]
>>  get_work_pool+0x2f2/0x340 kernel/workqueue.c:709
>>  __queue_work+0x2b3/0x1210 kernel/workqueue.c:1401
>>  queue_work_on+0x2e9/0x330 kernel/workqueue.c:1486
>>  queue_work include/linux/workqueue.h:487 [inline]
>>  strp_check_rcv+0x25/0x30 net/strparser/strparser.c:494
>
>
> It is not kcm_wq, it is strp_wq, and the work struct is strp->rx_work
> which lives in struct kcm_psock. The work is cancelled by strp_done(),
> it seems get queued again after strp_done()...


on 093b995e3b55a0ae0670226ddfcb05bfbf0099ae:

==
BUG: KASAN: use-after-free in worker_thread+0x1024/0x1340
kernel/workqueue.c:2229 at addr 88006d164ae0
Read of size 8 by task kworker/u8:3/25139
CPU: 2 PID: 25139 Comm: kworker/u8:3 Not tainted 4.11.0-rc3+ #364
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x1b8/0x28d lib/dump_stack.c:52
 kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
 print_address_description mm/kasan/report.c:210 [inline]
 kasan_report_error mm/kasan/report.c:294 [inline]
 kasan_report.part.2+0x1be/0x480 mm/kasan/report.c:316
 kasan_report mm/kasan/report.c:337 [inline]
 __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:337
 worker_thread+0x1024/0x1340 kernel/workqueue.c:2229
 kthread+0x359/0x420 kernel/kthread.c:229
 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
Object at 88006d1649c0, in cache kcm_psock_cache size: 616
Allocated:
PID = 25123
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:517
 set_track mm/kasan/kasan.c:529 [inline]
 kasan_kmalloc+0xbc/0xf0 mm/kasan/kasan.c:620
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:559
 kmem_cache_alloc+0x110/0x720 mm/slab.c:3572
 kmem_cache_zalloc include/linux/slab.h:653 [inline]
 kcm_attach net/kcm/kcmsock.c:1386 [inline]
 kcm_attach_ioctl net/kcm/kcmsock.c:1457 [inline]
 kcm_ioctl+0x2bc/0x17e0 net/kcm/kcmsock.c:1692
 sock_do_ioctl+0x65/0xb0 net/socket.c:895
 sock_ioctl+0x2c2/0x440 net/socket.c:993
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1af/0x16d0 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xc2
Freed:
PID = 25139
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:517
 set_track mm/kasan/kasan.c:529 [inline]
 kasan_slab_free+0x81/0xc0 mm/kasan/kasan.c:593
 __cache_free mm/slab.c:3514 [inline]
 kmem_cache_free+0x71/0x240 mm/slab.c:3774
 unreserve_psock+0x5d4/0x7b0 net/kcm/kcmsock.c:547
 kcm_write_msgs+0xba6/0x1ba0 net/kcm/kcmsock.c:590
 kcm_tx_work+0x32/0x1f0 net/kcm/kcmsock.c:731
 process_one_work+0xb20/0x1b40 kernel/workqueue.c:2097
 worker_thread+0x1b4/0x1340 kernel/workqueue.c:2231
 kthread+0x359/0x420 kernel/kthread.c:229
 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
Memory state around the buggy address:
 88006d164980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 88006d164a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>88006d164a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
   ^
 88006d164b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 88006d164b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==

Re: net/kcm: use-after-free in kcm_wq

2017-03-03 Thread Cong Wang 
On Fri, Mar 3, 2017 at 2:11 AM, Dmitry Vyukov  wrote:
> Also like this one:
>
> ==
> BUG: KASAN: use-after-free in atomic_long_read
> include/linux/compiler.h:254 [inline] at addr 8800538aba60
> BUG: KASAN: use-after-free in get_work_pool+0x2f2/0x340
> kernel/workqueue.c:709 at addr 8800538aba60
> Read of size 8 by task syz-executor6/7965
> CPU: 2 PID: 7965 Comm: syz-executor6 Not tainted 4.10.0+ #248
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:15 [inline]
>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>  print_address_description mm/kasan/report.c:204 [inline]
>  kasan_report_error mm/kasan/report.c:288 [inline]
>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>  kasan_report mm/kasan/report.c:331 [inline]
>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>  atomic_long_read include/linux/compiler.h:254 [inline]
>  get_work_pool+0x2f2/0x340 kernel/workqueue.c:709
>  __queue_work+0x2b3/0x1210 kernel/workqueue.c:1401
>  queue_work_on+0x2e9/0x330 kernel/workqueue.c:1486
>  queue_work include/linux/workqueue.h:487 [inline]
>  strp_check_rcv+0x25/0x30 net/strparser/strparser.c:494


It is not kcm_wq, it is strp_wq, and the work struct is strp->rx_work
which lives in struct kcm_psock. The work is cancelled by strp_done(),
it seems get queued again after strp_done()...


>  kcm_attach net/kcm/kcmsock.c:1434 [inline]
>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>  kcm_ioctl+0x8bb/0x1800 net/kcm/kcmsock.c:1690
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>  SYSC_ioctl fs/ioctl.c:698 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>  entry_SYSCALL_64_fastpath+0x1f/0xc2
> RIP: 0033:0x4458d9
> RSP: 002b:7f1dce9d1b58 EFLAGS: 0286 ORIG_RAX: 0010
> RAX: ffda RBX: 0024 RCX: 004458d9
> RDX: 20b68000 RSI: 89e0 RDI: 0024
> RBP: 006e0220 R08:  R09: 
> R10:  R11: 0286 R12: 007080a8
> R13:  R14: 7f1dce9d29c0 R15: 7f1dce9d2700
> Object at 8800538ab940, in cache kcm_psock_cache size: 616
> Allocated:
> PID = 7965
>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>  set_track mm/kasan/kasan.c:514 [inline]
>  kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605
>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
>  kmem_cache_alloc+0x102/0x680 mm/slab.c:3571
>  kmem_cache_zalloc include/linux/slab.h:653 [inline]
>  kcm_attach net/kcm/kcmsock.c:1384 [inline]
>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>  kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>  SYSC_ioctl fs/ioctl.c:698 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>  entry_SYSCALL_64_fastpath+0x1f/0xc2
> Freed:
> PID = 7982
>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>  set_track mm/kasan/kasan.c:514 [inline]
>  kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:578
>  __cache_free mm/slab.c:3513 [inline]
>  kmem_cache_free+0x71/0x240 mm/slab.c:3773
>  kcm_unattach+0xee7/0x1520 net/kcm/kcmsock.c:1558
>  kcm_unattach_ioctl net/kcm/kcmsock.c:1603 [inline]
>  kcm_ioctl+0xfae/0x1800 net/kcm/kcmsock.c:1700
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>  SYSC_ioctl fs/ioctl.c:698 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>  entry_SYSCALL_64_fastpath+0x1f/0xc2
> Memory state around the buggy address:
>  8800538ab900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>  8800538ab980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>8800538aba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>^
>  8800538aba80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  8800538abb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==

Re: net/kcm: use-after-free in kcm_wq

2017-03-03 Thread Cong Wang 
On Fri, Mar 3, 2017 at 2:11 AM, Dmitry Vyukov  wrote:
> Also like this one:
>
> ==
> BUG: KASAN: use-after-free in atomic_long_read
> include/linux/compiler.h:254 [inline] at addr 8800538aba60
> BUG: KASAN: use-after-free in get_work_pool+0x2f2/0x340
> kernel/workqueue.c:709 at addr 8800538aba60
> Read of size 8 by task syz-executor6/7965
> CPU: 2 PID: 7965 Comm: syz-executor6 Not tainted 4.10.0+ #248
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:15 [inline]
>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>  print_address_description mm/kasan/report.c:204 [inline]
>  kasan_report_error mm/kasan/report.c:288 [inline]
>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>  kasan_report mm/kasan/report.c:331 [inline]
>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>  atomic_long_read include/linux/compiler.h:254 [inline]
>  get_work_pool+0x2f2/0x340 kernel/workqueue.c:709
>  __queue_work+0x2b3/0x1210 kernel/workqueue.c:1401
>  queue_work_on+0x2e9/0x330 kernel/workqueue.c:1486
>  queue_work include/linux/workqueue.h:487 [inline]
>  strp_check_rcv+0x25/0x30 net/strparser/strparser.c:494


It is not kcm_wq, it is strp_wq, and the work struct is strp->rx_work
which lives in struct kcm_psock. The work is cancelled by strp_done(),
it seems get queued again after strp_done()...


>  kcm_attach net/kcm/kcmsock.c:1434 [inline]
>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>  kcm_ioctl+0x8bb/0x1800 net/kcm/kcmsock.c:1690
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>  SYSC_ioctl fs/ioctl.c:698 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>  entry_SYSCALL_64_fastpath+0x1f/0xc2
> RIP: 0033:0x4458d9
> RSP: 002b:7f1dce9d1b58 EFLAGS: 0286 ORIG_RAX: 0010
> RAX: ffda RBX: 0024 RCX: 004458d9
> RDX: 20b68000 RSI: 89e0 RDI: 0024
> RBP: 006e0220 R08:  R09: 
> R10:  R11: 0286 R12: 007080a8
> R13:  R14: 7f1dce9d29c0 R15: 7f1dce9d2700
> Object at 8800538ab940, in cache kcm_psock_cache size: 616
> Allocated:
> PID = 7965
>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>  set_track mm/kasan/kasan.c:514 [inline]
>  kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605
>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
>  kmem_cache_alloc+0x102/0x680 mm/slab.c:3571
>  kmem_cache_zalloc include/linux/slab.h:653 [inline]
>  kcm_attach net/kcm/kcmsock.c:1384 [inline]
>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>  kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>  SYSC_ioctl fs/ioctl.c:698 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>  entry_SYSCALL_64_fastpath+0x1f/0xc2
> Freed:
> PID = 7982
>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>  set_track mm/kasan/kasan.c:514 [inline]
>  kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:578
>  __cache_free mm/slab.c:3513 [inline]
>  kmem_cache_free+0x71/0x240 mm/slab.c:3773
>  kcm_unattach+0xee7/0x1520 net/kcm/kcmsock.c:1558
>  kcm_unattach_ioctl net/kcm/kcmsock.c:1603 [inline]
>  kcm_ioctl+0xfae/0x1800 net/kcm/kcmsock.c:1700
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>  SYSC_ioctl fs/ioctl.c:698 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>  entry_SYSCALL_64_fastpath+0x1f/0xc2
> Memory state around the buggy address:
>  8800538ab900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>  8800538ab980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>8800538aba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>^
>  8800538aba80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  8800538abb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==

Re: net/kcm: use-after-free in kcm_wq

2017-03-03 Thread Dmitry Vyukov 
On Fri, Mar 3, 2017 at 11:09 AM, Dmitry Vyukov  wrote:
> Hello,
>
> I am getting the following use-after-free reports while running
> syzkaller fuzzer on 86292b33d4b79ee03e2f43ea0381ef85f077c760. Seems
> that work items are not properly cancelled.
>
> ==
> BUG: KASAN: use-after-free in worker_thread+0x190f/0x1990
> kernel/workqueue.c:2228 at addr 880063de5a20
> Read of size 8 by task kworker/u8:0/5
> CPU: 1 PID: 5 Comm: kworker/u8:0 Not tainted 4.10.0+ #260
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:15 [inline]
>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>  print_address_description mm/kasan/report.c:204 [inline]
>  kasan_report_error mm/kasan/report.c:288 [inline]
>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>  kasan_report mm/kasan/report.c:331 [inline]
>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>  worker_thread+0x190f/0x1990 kernel/workqueue.c:2228
>  kthread+0x326/0x3f0 kernel/kthread.c:227
>  ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
> Object at 880063de5900, in cache kcm_psock_cache size: 616
> Allocated:
> PID = 11085
>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>  set_track mm/kasan/kasan.c:514 [inline]
>  kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605
>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
>  kmem_cache_alloc+0x102/0x680 mm/slab.c:3571
>  kmem_cache_zalloc include/linux/slab.h:653 [inline]
>  kcm_attach net/kcm/kcmsock.c:1384 [inline]
>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>  kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>  SYSC_ioctl fs/ioctl.c:698 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>  entry_SYSCALL_64_fastpath+0x1f/0xc2
> Freed:
> PID = 11095
>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>  set_track mm/kasan/kasan.c:514 [inline]
>  kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:578
>  __cache_free mm/slab.c:3513 [inline]
>  kmem_cache_free+0x71/0x240 mm/slab.c:3773
>  kcm_unattach+0xee7/0x1520 net/kcm/kcmsock.c:1558
>  kcm_unattach_ioctl net/kcm/kcmsock.c:1603 [inline]
>  kcm_ioctl+0xfae/0x1800 net/kcm/kcmsock.c:1700
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>  SYSC_ioctl fs/ioctl.c:698 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>  entry_SYSCALL_64_fastpath+0x1f/0xc2
> Memory state around the buggy address:
>  880063de5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  880063de5980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>880063de5a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>^
>  880063de5a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  880063de5b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
> ==
>
>
> ==
> BUG: KASAN: use-after-free in worker_thread+0x190f/0x1990
> kernel/workqueue.c:2228 at addr 88005378ed20
> Read of size 8 by task kworker/u8:2/6942
> CPU: 3 PID: 6942 Comm: kworker/u8:2 Not tainted 4.10.0+ #260
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:15 [inline]
>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>  print_address_description mm/kasan/report.c:204 [inline]
>  kasan_report_error mm/kasan/report.c:288 [inline]
>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>  kasan_report mm/kasan/report.c:331 [inline]
>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>  worker_thread+0x190f/0x1990 kernel/workqueue.c:2228
>  kthread+0x326/0x3f0 kernel/kthread.c:227
>  ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
> Object at 88005378ec00, in cache kcm_psock_cache size: 616
> Allocated:
> PID = 3023
>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>  set_track mm/kasan/kasan.c:514 [inline]
>  kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605
>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
>  kmem_cache_alloc+0x102/0x680 mm/slab.c:3571
>  kmem_cache_zalloc include/linux/slab.h:653 [inline]
>  kcm_attach net/kcm/kcmsock.c:1384 [inline]
>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>  kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43

Re: net/kcm: use-after-free in kcm_wq

2017-03-03 Thread Dmitry Vyukov 
On Fri, Mar 3, 2017 at 11:09 AM, Dmitry Vyukov  wrote:
> Hello,
>
> I am getting the following use-after-free reports while running
> syzkaller fuzzer on 86292b33d4b79ee03e2f43ea0381ef85f077c760. Seems
> that work items are not properly cancelled.
>
> ==
> BUG: KASAN: use-after-free in worker_thread+0x190f/0x1990
> kernel/workqueue.c:2228 at addr 880063de5a20
> Read of size 8 by task kworker/u8:0/5
> CPU: 1 PID: 5 Comm: kworker/u8:0 Not tainted 4.10.0+ #260
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:15 [inline]
>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>  print_address_description mm/kasan/report.c:204 [inline]
>  kasan_report_error mm/kasan/report.c:288 [inline]
>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>  kasan_report mm/kasan/report.c:331 [inline]
>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>  worker_thread+0x190f/0x1990 kernel/workqueue.c:2228
>  kthread+0x326/0x3f0 kernel/kthread.c:227
>  ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
> Object at 880063de5900, in cache kcm_psock_cache size: 616
> Allocated:
> PID = 11085
>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>  set_track mm/kasan/kasan.c:514 [inline]
>  kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605
>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
>  kmem_cache_alloc+0x102/0x680 mm/slab.c:3571
>  kmem_cache_zalloc include/linux/slab.h:653 [inline]
>  kcm_attach net/kcm/kcmsock.c:1384 [inline]
>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>  kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>  SYSC_ioctl fs/ioctl.c:698 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>  entry_SYSCALL_64_fastpath+0x1f/0xc2
> Freed:
> PID = 11095
>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>  set_track mm/kasan/kasan.c:514 [inline]
>  kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:578
>  __cache_free mm/slab.c:3513 [inline]
>  kmem_cache_free+0x71/0x240 mm/slab.c:3773
>  kcm_unattach+0xee7/0x1520 net/kcm/kcmsock.c:1558
>  kcm_unattach_ioctl net/kcm/kcmsock.c:1603 [inline]
>  kcm_ioctl+0xfae/0x1800 net/kcm/kcmsock.c:1700
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>  SYSC_ioctl fs/ioctl.c:698 [inline]
>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>  entry_SYSCALL_64_fastpath+0x1f/0xc2
> Memory state around the buggy address:
>  880063de5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  880063de5980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>880063de5a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>^
>  880063de5a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  880063de5b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
> ==
>
>
> ==
> BUG: KASAN: use-after-free in worker_thread+0x190f/0x1990
> kernel/workqueue.c:2228 at addr 88005378ed20
> Read of size 8 by task kworker/u8:2/6942
> CPU: 3 PID: 6942 Comm: kworker/u8:2 Not tainted 4.10.0+ #260
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:15 [inline]
>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>  print_address_description mm/kasan/report.c:204 [inline]
>  kasan_report_error mm/kasan/report.c:288 [inline]
>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>  kasan_report mm/kasan/report.c:331 [inline]
>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>  worker_thread+0x190f/0x1990 kernel/workqueue.c:2228
>  kthread+0x326/0x3f0 kernel/kthread.c:227
>  ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
> Object at 88005378ec00, in cache kcm_psock_cache size: 616
> Allocated:
> PID = 3023
>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>  set_track mm/kasan/kasan.c:514 [inline]
>  kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605
>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
>  kmem_cache_alloc+0x102/0x680 mm/slab.c:3571
>  kmem_cache_zalloc include/linux/slab.h:653 [inline]
>  kcm_attach net/kcm/kcmsock.c:1384 [inline]
>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>  kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690
>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>  vfs_ioctl fs/ioctl.c:43 [inline]
>

Re: net/kcm: use-after-free in kcm_wq

2017-03-03 Thread Dmitry Vyukov 
On Fri, Mar 3, 2017 at 11:11 AM, Dmitry Vyukov  wrote:
> On Fri, Mar 3, 2017 at 11:09 AM, Dmitry Vyukov  wrote:
>> Hello,
>>
>> I am getting the following use-after-free reports while running
>> syzkaller fuzzer on 86292b33d4b79ee03e2f43ea0381ef85f077c760. Seems
>> that work items are not properly cancelled.
>>
>> ==
>> BUG: KASAN: use-after-free in worker_thread+0x190f/0x1990
>> kernel/workqueue.c:2228 at addr 880063de5a20
>> Read of size 8 by task kworker/u8:0/5
>> CPU: 1 PID: 5 Comm: kworker/u8:0 Not tainted 4.10.0+ #260
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> Call Trace:
>>  __dump_stack lib/dump_stack.c:15 [inline]
>>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>>  print_address_description mm/kasan/report.c:204 [inline]
>>  kasan_report_error mm/kasan/report.c:288 [inline]
>>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>>  kasan_report mm/kasan/report.c:331 [inline]
>>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>>  worker_thread+0x190f/0x1990 kernel/workqueue.c:2228
>>  kthread+0x326/0x3f0 kernel/kthread.c:227
>>  ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
>> Object at 880063de5900, in cache kcm_psock_cache size: 616
>> Allocated:
>> PID = 11085
>>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>>  set_track mm/kasan/kasan.c:514 [inline]
>>  kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605
>>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
>>  kmem_cache_alloc+0x102/0x680 mm/slab.c:3571
>>  kmem_cache_zalloc include/linux/slab.h:653 [inline]
>>  kcm_attach net/kcm/kcmsock.c:1384 [inline]
>>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>>  kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690
>>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>>  vfs_ioctl fs/ioctl.c:43 [inline]
>>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>>  SYSC_ioctl fs/ioctl.c:698 [inline]
>>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>>  entry_SYSCALL_64_fastpath+0x1f/0xc2
>> Freed:
>> PID = 11095
>>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>>  set_track mm/kasan/kasan.c:514 [inline]
>>  kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:578
>>  __cache_free mm/slab.c:3513 [inline]
>>  kmem_cache_free+0x71/0x240 mm/slab.c:3773
>>  kcm_unattach+0xee7/0x1520 net/kcm/kcmsock.c:1558
>>  kcm_unattach_ioctl net/kcm/kcmsock.c:1603 [inline]
>>  kcm_ioctl+0xfae/0x1800 net/kcm/kcmsock.c:1700
>>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>>  vfs_ioctl fs/ioctl.c:43 [inline]
>>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>>  SYSC_ioctl fs/ioctl.c:698 [inline]
>>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>>  entry_SYSCALL_64_fastpath+0x1f/0xc2
>> Memory state around the buggy address:
>>  880063de5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>  880063de5980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>>880063de5a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>^
>>  880063de5a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>  880063de5b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
>> ==
>>
>>
>> ==
>> BUG: KASAN: use-after-free in worker_thread+0x190f/0x1990
>> kernel/workqueue.c:2228 at addr 88005378ed20
>> Read of size 8 by task kworker/u8:2/6942
>> CPU: 3 PID: 6942 Comm: kworker/u8:2 Not tainted 4.10.0+ #260
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> Call Trace:
>>  __dump_stack lib/dump_stack.c:15 [inline]
>>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>>  print_address_description mm/kasan/report.c:204 [inline]
>>  kasan_report_error mm/kasan/report.c:288 [inline]
>>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>>  kasan_report mm/kasan/report.c:331 [inline]
>>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>>  worker_thread+0x190f/0x1990 kernel/workqueue.c:2228
>>  kthread+0x326/0x3f0 kernel/kthread.c:227
>>  ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
>> Object at 88005378ec00, in cache kcm_psock_cache size: 616
>> Allocated:
>> PID = 3023
>>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>>  set_track mm/kasan/kasan.c:514 [inline]
>>  kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605
>>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
>>  kmem_cache_alloc+0x102/0x680 mm/slab.c:3571
>>  kmem_cache_zalloc include/linux/slab.h:653 [inline]
>>  kcm_attach net/kcm/kcmsock.c:1384 [inline]
>>  kcm_attach_ioctl

Re: net/kcm: use-after-free in kcm_wq

2017-03-03 Thread Dmitry Vyukov 
On Fri, Mar 3, 2017 at 11:11 AM, Dmitry Vyukov  wrote:
> On Fri, Mar 3, 2017 at 11:09 AM, Dmitry Vyukov  wrote:
>> Hello,
>>
>> I am getting the following use-after-free reports while running
>> syzkaller fuzzer on 86292b33d4b79ee03e2f43ea0381ef85f077c760. Seems
>> that work items are not properly cancelled.
>>
>> ==
>> BUG: KASAN: use-after-free in worker_thread+0x190f/0x1990
>> kernel/workqueue.c:2228 at addr 880063de5a20
>> Read of size 8 by task kworker/u8:0/5
>> CPU: 1 PID: 5 Comm: kworker/u8:0 Not tainted 4.10.0+ #260
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> Call Trace:
>>  __dump_stack lib/dump_stack.c:15 [inline]
>>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>>  print_address_description mm/kasan/report.c:204 [inline]
>>  kasan_report_error mm/kasan/report.c:288 [inline]
>>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>>  kasan_report mm/kasan/report.c:331 [inline]
>>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>>  worker_thread+0x190f/0x1990 kernel/workqueue.c:2228
>>  kthread+0x326/0x3f0 kernel/kthread.c:227
>>  ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
>> Object at 880063de5900, in cache kcm_psock_cache size: 616
>> Allocated:
>> PID = 11085
>>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>>  set_track mm/kasan/kasan.c:514 [inline]
>>  kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605
>>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
>>  kmem_cache_alloc+0x102/0x680 mm/slab.c:3571
>>  kmem_cache_zalloc include/linux/slab.h:653 [inline]
>>  kcm_attach net/kcm/kcmsock.c:1384 [inline]
>>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>>  kcm_ioctl+0x303/0x1800 net/kcm/kcmsock.c:1690
>>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>>  vfs_ioctl fs/ioctl.c:43 [inline]
>>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>>  SYSC_ioctl fs/ioctl.c:698 [inline]
>>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>>  entry_SYSCALL_64_fastpath+0x1f/0xc2
>> Freed:
>> PID = 11095
>>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>>  set_track mm/kasan/kasan.c:514 [inline]
>>  kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:578
>>  __cache_free mm/slab.c:3513 [inline]
>>  kmem_cache_free+0x71/0x240 mm/slab.c:3773
>>  kcm_unattach+0xee7/0x1520 net/kcm/kcmsock.c:1558
>>  kcm_unattach_ioctl net/kcm/kcmsock.c:1603 [inline]
>>  kcm_ioctl+0xfae/0x1800 net/kcm/kcmsock.c:1700
>>  sock_do_ioctl+0x65/0xb0 net/socket.c:895
>>  sock_ioctl+0x2c2/0x440 net/socket.c:993
>>  vfs_ioctl fs/ioctl.c:43 [inline]
>>  do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
>>  SYSC_ioctl fs/ioctl.c:698 [inline]
>>  SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
>>  entry_SYSCALL_64_fastpath+0x1f/0xc2
>> Memory state around the buggy address:
>>  880063de5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>  880063de5980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>>880063de5a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>^
>>  880063de5a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>>  880063de5b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
>> ==
>>
>>
>> ==
>> BUG: KASAN: use-after-free in worker_thread+0x190f/0x1990
>> kernel/workqueue.c:2228 at addr 88005378ed20
>> Read of size 8 by task kworker/u8:2/6942
>> CPU: 3 PID: 6942 Comm: kworker/u8:2 Not tainted 4.10.0+ #260
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> Call Trace:
>>  __dump_stack lib/dump_stack.c:15 [inline]
>>  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
>>  kasan_object_err+0x1c/0x70 mm/kasan/report.c:166
>>  print_address_description mm/kasan/report.c:204 [inline]
>>  kasan_report_error mm/kasan/report.c:288 [inline]
>>  kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310
>>  kasan_report mm/kasan/report.c:331 [inline]
>>  __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331
>>  worker_thread+0x190f/0x1990 kernel/workqueue.c:2228
>>  kthread+0x326/0x3f0 kernel/kthread.c:227
>>  ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
>> Object at 88005378ec00, in cache kcm_psock_cache size: 616
>> Allocated:
>> PID = 3023
>>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
>>  save_stack+0x43/0xd0 mm/kasan/kasan.c:502
>>  set_track mm/kasan/kasan.c:514 [inline]
>>  kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605
>>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
>>  kmem_cache_alloc+0x102/0x680 mm/slab.c:3571
>>  kmem_cache_zalloc include/linux/slab.h:653 [inline]
>>  kcm_attach net/kcm/kcmsock.c:1384 [inline]
>>  kcm_attach_ioctl net/kcm/kcmsock.c:1455 [inline]
>>  kcm_ioctl+0x303/0x1800