KASAN: global-out-of-bounds Read in dvb_pll_attach

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 7829a896 usb-fuzzer: main usb gadget fuzzer driver
git tree: https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=150f8c47a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=f6d4561982f71f63
dashboard link: https://syzkaller.appspot.com/bug?extid=8a8f48672560c8ca59dd
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16384e27a00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16056038600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+8a8f48...@syzkaller.appspotmail.com

usb 1-1: dvb_usb_v2: will pass the complete MPEG2 transport stream to the
software demuxer
dvbdev: DVB: registering new adapter (774 Friio White ISDB-T USB2.0)
usb 1-1: media controller created
dvbdev: dvb_create_media_entity: media entity 'dvb-demux' registered.
tc90522 0-0018: Toshiba TC90522 attached.
usb 1-1: DVB: registering adapter 0 frontend 0 (Toshiba TC90522 ISDB-T
module)...
dvbdev: dvb_create_media_entity: media entity 'Toshiba TC90522 ISDB-T
module' registered.
==================================================================
BUG: KASAN: global-out-of-bounds in dvb_pll_attach+0x6c5/0x830
drivers/media/dvb-frontends/dvb-pll.c:798
Read of size 4 at addr ffffffff89c9e5e0 by task kworker/0:1/12

CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.2.0-rc6+ #13
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
print_address_description+0x67/0x231 mm/kasan/report.c:188
__kasan_report.cold+0x1a/0x32 mm/kasan/report.c:317
kasan_report+0xe/0x20 mm/kasan/common.c:614
dvb_pll_attach+0x6c5/0x830 drivers/media/dvb-frontends/dvb-pll.c:798
dvb_pll_probe+0xfe/0x174 drivers/media/dvb-frontends/dvb-pll.c:877
i2c_device_probe+0x790/0xaa0 drivers/i2c/i2c-core-base.c:389
really_probe+0x281/0x660 drivers/base/dd.c:509
driver_probe_device+0x104/0x210 drivers/base/dd.c:670
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:777
bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
__device_attach+0x217/0x360 drivers/base/dd.c:843
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
device_add+0xae6/0x16f0 drivers/base/core.c:2111
i2c_new_client_device+0x5b3/0xc40 drivers/i2c/i2c-core-base.c:778
i2c_new_device+0x19/0x50 drivers/i2c/i2c-core-base.c:821
dvb_module_probe+0xf9/0x220 drivers/media/dvb-core/dvbdev.c:985
friio_tuner_attach+0x125/0x1d0 drivers/media/usb/dvb-usb-v2/gl861.c:536
dvb_usbv2_adapter_frontend_init
drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:675 [inline]
dvb_usbv2_adapter_init drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:804
[inline]
dvb_usbv2_init drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:865 [inline]
dvb_usbv2_probe.cold+0x24dc/0x255d
drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:980
usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
really_probe+0x281/0x660 drivers/base/dd.c:509
driver_probe_device+0x104/0x210 drivers/base/dd.c:670
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:777
bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
__device_attach+0x217/0x360 drivers/base/dd.c:843
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
device_add+0xae6/0x16f0 drivers/base/core.c:2111
usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
really_probe+0x281/0x660 drivers/base/dd.c:509
driver_probe_device+0x104/0x210 drivers/base/dd.c:670
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:777
bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
__device_attach+0x217/0x360 drivers/base/dd.c:843
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
device_add+0xae6/0x16f0 drivers/base/core.c:2111
usb_new_device.cold+0x8c1/0x1016 drivers/usb/core/hub.c:2534
hub_port_connect drivers/usb/core/hub.c:5089 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
port_event drivers/usb/core/hub.c:5350 [inline]
hub_event+0x1ada/0x3590 drivers/usb/core/hub.c:5432
process_one_work+0x905/0x1570 kernel/workqueue.c:2269
process_scheduled_works kernel/workqueue.c:2331 [inline]
worker_thread+0x7ab/0xe20 kernel/workqueue.c:2417
kthread+0x30b/0x410 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the variable:
id+0x100/0x120

Memory state around the buggy address:
ffffffff89c9e480: fa fa fa fa 00 00 fa fa fa fa fa fa 00 00 00 00
ffffffff89c9e500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffffffff89c9e580: 00 00 00 00 00 00 00 00 00 00 00 00 fa fa fa fa
^
ffffffff89c9e600: 04 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa
ffffffff89c9e680: 04 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa
==================================================================


---
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 syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

[bnva...@gmail.com]

#syz test https://github.com/vandanabn/linux 44eb5beb9da4e49b4b2237522b619a0e059a06bd

On Wednesday, July 10, 2019 at 10:48:09 PM UTC+5:30, syzbot wrote:

Hello,

syzbot found the following crash on:

HEAD commit:    7829a896 usb-fuzzer: main usb gadget fuzzer driver
git tree:       https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=150f8c47a00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f6d4561982f71f63
dashboard link: https://syzkaller.appspot.com/bug?extid=8a8f48672560c8ca59dd
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16384e27a00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16056038600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:

Reported-by: syz...@syzkaller.appspotmail.com

[syzbot]

> #syz test https://github.com/vandanabn/linux

I see the command but can't find the corresponding bug.
Please resend the email to syzbo...@syzkaller.appspotmail.com address
that is the sender of the bug report (also present in the Reported-by tag).

> 44eb5beb9da4e49b4b2237522b619a0e059a06bd

> On Wednesday, July 10, 2019 at 10:48:09 PM UTC+5:30, syzbot wrote:

>> Hello,

>> syzbot found the following crash on:

>> HEAD commit: 7829a896 usb-fuzzer: main usb gadget fuzzer driver
>> git tree: https://github.com/google/kasan.git usb-fuzzer
>> console output: https://syzkaller.appspot.com/x/log.txt?x=150f8c47a00000
>> kernel config:
>> https://syzkaller.appspot.com/x/.config?x=f6d4561982f71f63
>> dashboard link:
>> https://syzkaller.appspot.com/bug?extid=8a8f48672560c8ca59dd
>> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
>> syz repro:
>> https://syzkaller.appspot.com/x/repro.syz?x=16384e27a00000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16056038600000

>> IMPORTANT: if you fix the bug, please add the following tag to the
>> commit:

>> Reported-by: syz...@syzkaller.appspotmail.com <javascript:>

>> <javascript:>.

>> syzbot will keep track of this bug report. See:
>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>> syzbot can test patches for this bug, for details see:
>> https://goo.gl/tpsmEJ#testing-patches

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[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger
crash:

Reported-and-tested-by:
syzbot+8a8f48...@syzkaller.appspotmail.com

Tested on:

commit: e9f92f26 media:dvb-frontend: fix syzbot global out of boun..
git tree: https://github.com/vandanabn/linux
kernel config: https://syzkaller.appspot.com/x/.config?x=e966d7d1bdbee4ed

compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Note: testing is done by a robot and is best-effort only.

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger
crash:

Reported-and-tested-by:
syzbot+8a8f48...@syzkaller.appspotmail.com

Tested on:

commit: 6a3599ce usb-fuzzer: main usb gadget fuzzer driver

git tree: https://github.com/google/kasan.git usb-fuzzer

kernel config: https://syzkaller.appspot.com/x/.config?x=d90745bdf884fc0a

compiler: gcc (GCC) 9.0.0 20181231 (experimental)

patch: https://syzkaller.appspot.com/x/patch.diff?x=15bfccd0600000

[Andrey Konovalov]

On Wed, Jul 10, 2019 at 7:18 PM syzbot
<syzbot+8a8f48...@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 7829a896 usb-fuzzer: main usb gadget fuzzer driver
> git tree: https://github.com/google/kasan.git usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=150f8c47a00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=f6d4561982f71f63
> dashboard link: https://syzkaller.appspot.com/bug?extid=8a8f48672560c8ca59dd
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16384e27a00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16056038600000

You need to keep the bot in the recipients and also USB bugs can only
be tested on the usb-fuzzer tree.

#syz test: https://github.com/google/kasan.git usb-fuzzer

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger
crash:

Reported-and-tested-by:
syzbot+8a8f48...@syzkaller.appspotmail.com

Tested on:

commit: 6a3599ce usb-fuzzer: main usb gadget fuzzer driver

git tree: https://github.com/google/kasan.git usb-fuzzer

kernel config: https://syzkaller.appspot.com/x/.config?x=d90745bdf884fc0a

compiler: gcc (GCC) 9.0.0 20181231 (experimental)

patch: https://syzkaller.appspot.com/x/patch.diff?x=1454f4d0600000

[Vandana BN]

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger
crash:

Reported-and-tested-by:
syzbot+8a8f48...@syzkaller.appspotmail.com

Tested on:

commit: 6a3599ce usb-fuzzer: main usb gadget fuzzer driver
git tree: https://github.com/google/kasan.git usb-fuzzer
kernel config: https://syzkaller.appspot.com/x/.config?x=d90745bdf884fc0a
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

patch: https://syzkaller.appspot.com/x/patch.diff?x=145eaa34600000

[Andrey Konovalov]

Hi bnvandana,

Could you submit this patch? Syzbot testing shows that is fixes the issue.

Thanks!

[Sean Young]

The patch had issues (see discussion in the thread). I created this patch
but I see now I did not include the correct Reported-by: tag.

https://www.mail-archive.com/linux...@vger.kernel.org/msg148889.html

Thanks

Sean

[Andrey Konovalov]

No problem, we can mark the fix manually:

#syz fix: media: dvb-frontends: use ida for pll number

Thanks!