Re: KASAN: use-after-free Read in work_is_static_object

2018-05-08 Thread Eric Biggers 
On Mon, Jan 08, 2018 at 12:58:11PM +0100, 'Dmitry Vyukov' via syzkaller-bugs 
wrote:
> On Mon, Jan 8, 2018 at 12:55 PM, Dmitry Vyukov  wrote:
> > On Mon, Jan 8, 2018 at 12:43 PM, syzbot
> >  wrote:
> >> Hello,
> >>
> >> syzkaller hit the following crash on
> >> f66faae2f80a45feafc04ce63ef744ac4b6e8c05
> >> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
> >> compiler: gcc (GCC) 7.1.1 20170620
> >> .config is attached
> >> Raw console output is attached.
> >> Unfortunately, I don't have any reproducer for this bug yet.
> >>
> >>
> >> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> >> Reported-by: syzbot+40396d275b34b0dd5...@syzkaller.appspotmail.com
> >> It will help syzbot understand when the bug is fixed. See footer for
> >> details.
> >> If you forward the report, please keep this part and the footer.
> >
> >
> > This looks like an issue in kcm sockets, so +kcm maintainers.
> 
> FTR, guilty file extraction was fixed to ignore kernel/workqueue.c:
> https://github.com/google/syzkaller/commit/1014e5506e35965f3bad13fabb08666134d0b273
> Presumably for bugs in workqueue usually the caller is guilty.
> 
> 
> >> device ip6_vti0 entered promiscuous mode
> >> ==
> >> BUG: KASAN: use-after-free in constant_test_bit
> >> arch/x86/include/asm/bitops.h:325 [inline]
> >> BUG: KASAN: use-after-free in work_is_static_object+0x39/0x40
> >> kernel/workqueue.c:443
> >> Read of size 8 at addr 8801beca5788 by task syz-executor2/12922
> >>
> >> CPU: 0 PID: 12922 Comm: syz-executor2 Not tainted 4.15.0-rc5+ #178
> >> 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
> >>  constant_test_bit arch/x86/include/asm/bitops.h:325 [inline]
> >>  work_is_static_object+0x39/0x40 kernel/workqueue.c:443
> >>  debug_object_activate+0x36f/0x730 lib/debugobjects.c:470
> >>  debug_work_activate kernel/workqueue.c:492 [inline]
> >>  __queue_work+0x163/0x1230 kernel/workqueue.c:1381
> >>  queue_work_on+0x16a/0x1c0 kernel/workqueue.c:1487
> >>  queue_work include/linux/workqueue.h:488 [inline]
> >>  strp_check_rcv+0x25/0x30 net/strparser/strparser.c:552
> >>  kcm_attach net/kcm/kcmsock.c:1439 [inline]
> >>  kcm_attach_ioctl net/kcm/kcmsock.c:1460 [inline]
> >>  kcm_ioctl+0x82f/0x1690 net/kcm/kcmsock.c:1665
> >>  sock_do_ioctl+0x65/0xb0 net/socket.c:956
> >>  sock_ioctl+0x2c2/0x440 net/socket.c:1053
> >>  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+0x23/0x9a
> >> RIP: 0033:0x452ac9
> >> RSP: 002b:7f1bbd860c58 EFLAGS: 0212 ORIG_RAX: 0010
> >> RAX: ffda RBX: 0071bea0 RCX: 00452ac9
> >> RDX: 20954ff8 RSI: 89e0 RDI: 0017
> >> RBP: 057b R08:  R09: 
> >> R10:  R11: 0212 R12: 006f6428
> >> R13:  R14: 7f1bbd8616d4 R15: 
> >>
> >> Allocated by task 12922:
> >>  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
> >>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
> >>  kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544
> >>  kmem_cache_zalloc include/linux/slab.h:678 [inline]
> >>  kcm_attach net/kcm/kcmsock.c:1394 [inline]
> >>  kcm_attach_ioctl net/kcm/kcmsock.c:1460 [inline]
> >>  kcm_ioctl+0x2d2/0x1690 net/kcm/kcmsock.c:1665
> >>  sock_do_ioctl+0x65/0xb0 net/socket.c:956
> >>  sock_ioctl+0x2c2/0x440 net/socket.c:1053
> >>  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+0x23/0x9a
> >>
> >> Freed by task 12929:
> >>  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]
> >>  kmem_cache_free+0x83/0x2a0 mm/slab.c:3746
> >>  kcm_unattach+0xe53/0x1510 net/kcm/kcmsock.c:1563
> >>  kcm_unattach_ioctl net/kcm/kcmsock.c:1608 [inline]
> >>  kcm_ioctl+0xe54/0x1690 net/kcm/kcmsock.c:1675
> >>  sock_do_ioctl+0x65/0xb0 net/socket.c:956
> >>  sock_ioctl+0x2c2/0x440 net/socket.c:1053
> >>  vfs_ioctl fs/ioctl.c:46 [inline]
> >>  do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686
> >>  SYSC_ioctl

Re: KASAN: use-after-free Read in work_is_static_object

2018-01-08 Thread Dmitry Vyukov 
On Mon, Jan 8, 2018 at 12:55 PM, Dmitry Vyukov  wrote:
> On Mon, Jan 8, 2018 at 12:43 PM, syzbot
>  wrote:
>> Hello,
>>
>> syzkaller hit the following crash on
>> f66faae2f80a45feafc04ce63ef744ac4b6e8c05
>> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
>> compiler: gcc (GCC) 7.1.1 20170620
>> .config is attached
>> Raw console output is attached.
>> Unfortunately, I don't have any reproducer for this bug yet.
>>
>>
>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>> Reported-by: syzbot+40396d275b34b0dd5...@syzkaller.appspotmail.com
>> It will help syzbot understand when the bug is fixed. See footer for
>> details.
>> If you forward the report, please keep this part and the footer.
>
>
> This looks like an issue in kcm sockets, so +kcm maintainers.

FTR, guilty file extraction was fixed to ignore kernel/workqueue.c:
https://github.com/google/syzkaller/commit/1014e5506e35965f3bad13fabb08666134d0b273
Presumably for bugs in workqueue usually the caller is guilty.


>> device ip6_vti0 entered promiscuous mode
>> ==
>> BUG: KASAN: use-after-free in constant_test_bit
>> arch/x86/include/asm/bitops.h:325 [inline]
>> BUG: KASAN: use-after-free in work_is_static_object+0x39/0x40
>> kernel/workqueue.c:443
>> Read of size 8 at addr 8801beca5788 by task syz-executor2/12922
>>
>> CPU: 0 PID: 12922 Comm: syz-executor2 Not tainted 4.15.0-rc5+ #178
>> 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
>>  constant_test_bit arch/x86/include/asm/bitops.h:325 [inline]
>>  work_is_static_object+0x39/0x40 kernel/workqueue.c:443
>>  debug_object_activate+0x36f/0x730 lib/debugobjects.c:470
>>  debug_work_activate kernel/workqueue.c:492 [inline]
>>  __queue_work+0x163/0x1230 kernel/workqueue.c:1381
>>  queue_work_on+0x16a/0x1c0 kernel/workqueue.c:1487
>>  queue_work include/linux/workqueue.h:488 [inline]
>>  strp_check_rcv+0x25/0x30 net/strparser/strparser.c:552
>>  kcm_attach net/kcm/kcmsock.c:1439 [inline]
>>  kcm_attach_ioctl net/kcm/kcmsock.c:1460 [inline]
>>  kcm_ioctl+0x82f/0x1690 net/kcm/kcmsock.c:1665
>>  sock_do_ioctl+0x65/0xb0 net/socket.c:956
>>  sock_ioctl+0x2c2/0x440 net/socket.c:1053
>>  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+0x23/0x9a
>> RIP: 0033:0x452ac9
>> RSP: 002b:7f1bbd860c58 EFLAGS: 0212 ORIG_RAX: 0010
>> RAX: ffda RBX: 0071bea0 RCX: 00452ac9
>> RDX: 20954ff8 RSI: 89e0 RDI: 0017
>> RBP: 057b R08:  R09: 
>> R10:  R11: 0212 R12: 006f6428
>> R13:  R14: 7f1bbd8616d4 R15: 
>>
>> Allocated by task 12922:
>>  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
>>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
>>  kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544
>>  kmem_cache_zalloc include/linux/slab.h:678 [inline]
>>  kcm_attach net/kcm/kcmsock.c:1394 [inline]
>>  kcm_attach_ioctl net/kcm/kcmsock.c:1460 [inline]
>>  kcm_ioctl+0x2d2/0x1690 net/kcm/kcmsock.c:1665
>>  sock_do_ioctl+0x65/0xb0 net/socket.c:956
>>  sock_ioctl+0x2c2/0x440 net/socket.c:1053
>>  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+0x23/0x9a
>>
>> Freed by task 12929:
>>  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]
>>  kmem_cache_free+0x83/0x2a0 mm/slab.c:3746
>>  kcm_unattach+0xe53/0x1510 net/kcm/kcmsock.c:1563
>>  kcm_unattach_ioctl net/kcm/kcmsock.c:1608 [inline]
>>  kcm_ioctl+0xe54/0x1690 net/kcm/kcmsock.c:1675
>>  sock_do_ioctl+0x65/0xb0 net/socket.c:956
>>  sock_ioctl+0x2c2/0x440 net/socket.c:1053
>>  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+0x23/0x9a
>>
>> The buggy address belongs to the object at 8801beca56c0
>>  which belongs to the cache kcm_psock_cache of size 544
>> The buggy address is located 200 bytes inside of
>>  544-byte region

Re: KASAN: use-after-free Read in work_is_static_object

2018-01-08 Thread Dmitry Vyukov 
On Mon, Jan 8, 2018 at 12:43 PM, syzbot
 wrote:
> Hello,
>
> syzkaller hit the following crash on
> f66faae2f80a45feafc04ce63ef744ac4b6e8c05
> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> Unfortunately, I don't have any reproducer for this bug yet.
>
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+40396d275b34b0dd5...@syzkaller.appspotmail.com
> It will help syzbot understand when the bug is fixed. See footer for
> details.
> If you forward the report, please keep this part and the footer.


This looks like an issue in kcm sockets, so +kcm maintainers.


> device ip6_vti0 entered promiscuous mode
> ==
> BUG: KASAN: use-after-free in constant_test_bit
> arch/x86/include/asm/bitops.h:325 [inline]
> BUG: KASAN: use-after-free in work_is_static_object+0x39/0x40
> kernel/workqueue.c:443
> Read of size 8 at addr 8801beca5788 by task syz-executor2/12922
>
> CPU: 0 PID: 12922 Comm: syz-executor2 Not tainted 4.15.0-rc5+ #178
> 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
>  constant_test_bit arch/x86/include/asm/bitops.h:325 [inline]
>  work_is_static_object+0x39/0x40 kernel/workqueue.c:443
>  debug_object_activate+0x36f/0x730 lib/debugobjects.c:470
>  debug_work_activate kernel/workqueue.c:492 [inline]
>  __queue_work+0x163/0x1230 kernel/workqueue.c:1381
>  queue_work_on+0x16a/0x1c0 kernel/workqueue.c:1487
>  queue_work include/linux/workqueue.h:488 [inline]
>  strp_check_rcv+0x25/0x30 net/strparser/strparser.c:552
>  kcm_attach net/kcm/kcmsock.c:1439 [inline]
>  kcm_attach_ioctl net/kcm/kcmsock.c:1460 [inline]
>  kcm_ioctl+0x82f/0x1690 net/kcm/kcmsock.c:1665
>  sock_do_ioctl+0x65/0xb0 net/socket.c:956
>  sock_ioctl+0x2c2/0x440 net/socket.c:1053
>  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+0x23/0x9a
> RIP: 0033:0x452ac9
> RSP: 002b:7f1bbd860c58 EFLAGS: 0212 ORIG_RAX: 0010
> RAX: ffda RBX: 0071bea0 RCX: 00452ac9
> RDX: 20954ff8 RSI: 89e0 RDI: 0017
> RBP: 057b R08:  R09: 
> R10:  R11: 0212 R12: 006f6428
> R13:  R14: 7f1bbd8616d4 R15: 
>
> Allocated by task 12922:
>  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
>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
>  kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544
>  kmem_cache_zalloc include/linux/slab.h:678 [inline]
>  kcm_attach net/kcm/kcmsock.c:1394 [inline]
>  kcm_attach_ioctl net/kcm/kcmsock.c:1460 [inline]
>  kcm_ioctl+0x2d2/0x1690 net/kcm/kcmsock.c:1665
>  sock_do_ioctl+0x65/0xb0 net/socket.c:956
>  sock_ioctl+0x2c2/0x440 net/socket.c:1053
>  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+0x23/0x9a
>
> Freed by task 12929:
>  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]
>  kmem_cache_free+0x83/0x2a0 mm/slab.c:3746
>  kcm_unattach+0xe53/0x1510 net/kcm/kcmsock.c:1563
>  kcm_unattach_ioctl net/kcm/kcmsock.c:1608 [inline]
>  kcm_ioctl+0xe54/0x1690 net/kcm/kcmsock.c:1675
>  sock_do_ioctl+0x65/0xb0 net/socket.c:956
>  sock_ioctl+0x2c2/0x440 net/socket.c:1053
>  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+0x23/0x9a
>
> The buggy address belongs to the object at 8801beca56c0
>  which belongs to the cache kcm_psock_cache of size 544
> The buggy address is located 200 bytes inside of
>  544-byte region [8801beca56c0, 8801beca58e0)
> The buggy address belongs to the page:
> page:5180a80a count:1 mapcount:0 mapping:58aa9a5c index:0x0
> compound_mapcount: 0
> flags: 0x2fffc008100(slab|head)
> raw: 02fffc008100 8801beca40c0  0001000b
> raw: 8801d31e8a48 8801d31e8a48 8801d3f6a380 
> page dumped because: kasan: