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* KASAN: use-after-free Read in cpia2_usb_disconnect
@ 2019-04-16 11:16 syzbot
  2019-07-03  1:01 ` syzbot
  0 siblings, 1 reply; 5+ messages in thread
From: syzbot @ 2019-04-16 11:16 UTC (permalink / raw)
  To: andreyknvl, hverkuil-cisco, keescook, linux-kernel, linux-media,
	linux-usb, mchehab, sakari.ailus, syzkaller-bugs

Hello,

syzbot found the following crash on:

HEAD commit:    9a33b369 usb-fuzzer: main usb gadget fuzzer driver
git tree:       https://github.com/google/kasan/tree/usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=1463a267200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15
dashboard link: https://syzkaller.appspot.com/bug?extid=0c90fc937c84f97d0aa6
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13af9c23200000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0c90fc937c84f97d0aa6@syzkaller.appspotmail.com

cpia2: Control message failed, err val = -19
cpia2: Message: request = 0x1, start = 0xA9
cpia2: Message: count = 1, register[0] = 0x0
cpia2: Unexpected error: -19
==================================================================
BUG: KASAN: use-after-free in cpia2_usb_disconnect+0x1a9/0x1c0  
drivers/media/usb/cpia2/cpia2_usb.c:907
Read of size 8 at addr ffff8880a09f0a58 by task kworker/0:1/12

CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.1.0-rc4-319354-g9a33b36 #3
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+0xe8/0x16e lib/dump_stack.c:113
  print_address_description+0x6c/0x236 mm/kasan/report.c:187
  kasan_report.cold+0x1a/0x3c mm/kasan/report.c:317
  cpia2_usb_disconnect+0x1a9/0x1c0 drivers/media/usb/cpia2/cpia2_usb.c:907
  usb_unbind_interface+0x1c9/0x980 drivers/usb/core/driver.c:423
  __device_release_driver drivers/base/dd.c:1082 [inline]
  device_release_driver_internal+0x436/0x4f0 drivers/base/dd.c:1113
  bus_remove_device+0x302/0x5c0 drivers/base/bus.c:556
  device_del+0x467/0xb90 drivers/base/core.c:2269
  usb_disable_device+0x242/0x790 drivers/usb/core/message.c:1235
  usb_disconnect+0x298/0x870 drivers/usb/core/hub.c:2197
  hub_port_connect drivers/usb/core/hub.c:4940 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
  port_event drivers/usb/core/hub.c:5350 [inline]
  hub_event+0xcd2/0x3b00 drivers/usb/core/hub.c:5432
  process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
  process_scheduled_works kernel/workqueue.c:2331 [inline]
  worker_thread+0x7b0/0xe20 kernel/workqueue.c:2417
  kthread+0x313/0x420 kernel/kthread.c:253
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Allocated by task 12:
  set_track mm/kasan/common.c:87 [inline]
  __kasan_kmalloc mm/kasan/common.c:497 [inline]
  __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:470
  kmalloc include/linux/slab.h:547 [inline]
  kzalloc include/linux/slab.h:742 [inline]
  cpia2_init_camera_struct+0x45/0x110  
drivers/media/usb/cpia2/cpia2_core.c:2185
  cpia2_usb_probe.cold+0x37/0x45a drivers/media/usb/cpia2/cpia2_usb.c:842
  usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
  really_probe+0x2da/0xb10 drivers/base/dd.c:509
  driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
  __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
  bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
  __device_attach+0x223/0x3a0 drivers/base/dd.c:844
  bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
  device_add+0xad2/0x16e0 drivers/base/core.c:2106
  usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
  generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
  usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
  really_probe+0x2da/0xb10 drivers/base/dd.c:509
  driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
  __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
  bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
  __device_attach+0x223/0x3a0 drivers/base/dd.c:844
  bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
  device_add+0xad2/0x16e0 drivers/base/core.c:2106
  usb_new_device.cold+0x537/0xccf 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+0x138e/0x3b00 drivers/usb/core/hub.c:5432
  process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
  worker_thread+0x9b/0xe20 kernel/workqueue.c:2415
  kthread+0x313/0x420 kernel/kthread.c:253
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Freed by task 12:
  set_track mm/kasan/common.c:87 [inline]
  __kasan_slab_free+0x130/0x180 mm/kasan/common.c:459
  slab_free_hook mm/slub.c:1429 [inline]
  slab_free_freelist_hook+0x5e/0x140 mm/slub.c:1456
  slab_free mm/slub.c:3003 [inline]
  kfree+0xce/0x290 mm/slub.c:3958
  v4l2_device_release drivers/media/v4l2-core/v4l2-device.c:67 [inline]
  kref_put include/linux/kref.h:67 [inline]
  v4l2_device_put+0x7e/0xa0 drivers/media/v4l2-core/v4l2-device.c:72
  cpia2_usb_disconnect+0x7e/0x1c0 drivers/media/usb/cpia2/cpia2_usb.c:905
  usb_unbind_interface+0x1c9/0x980 drivers/usb/core/driver.c:423
  __device_release_driver drivers/base/dd.c:1082 [inline]
  device_release_driver_internal+0x436/0x4f0 drivers/base/dd.c:1113
  bus_remove_device+0x302/0x5c0 drivers/base/bus.c:556
  device_del+0x467/0xb90 drivers/base/core.c:2269
  usb_disable_device+0x242/0x790 drivers/usb/core/message.c:1235
  usb_disconnect+0x298/0x870 drivers/usb/core/hub.c:2197
  hub_port_connect drivers/usb/core/hub.c:4940 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
  port_event drivers/usb/core/hub.c:5350 [inline]
  hub_event+0xcd2/0x3b00 drivers/usb/core/hub.c:5432
  process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
  process_scheduled_works kernel/workqueue.c:2331 [inline]
  worker_thread+0x7b0/0xe20 kernel/workqueue.c:2417
  kthread+0x313/0x420 kernel/kthread.c:253
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8880a09f0000
  which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 2648 bytes inside of
  4096-byte region [ffff8880a09f0000, ffff8880a09f1000)
The buggy address belongs to the page:
page:ffffea0002827c00 count:1 mapcount:0 mapping:ffff88812c3f4600 index:0x0  
compound_mapcount: 0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 dead000000000100 dead000000000200 ffff88812c3f4600
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8880a09f0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8880a09f0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8880a09f0a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                     ^
  ffff8880a09f0a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8880a09f0b00: 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 syzkaller@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

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: KASAN: use-after-free Read in cpia2_usb_disconnect
  2019-04-16 11:16 KASAN: use-after-free Read in cpia2_usb_disconnect syzbot
@ 2019-07-03  1:01 ` syzbot
  2019-07-03  7:42   ` Oliver Neukum
  0 siblings, 1 reply; 5+ messages in thread
From: syzbot @ 2019-07-03  1:01 UTC (permalink / raw)
  To: allison, andreyknvl, hverkuil-cisco, keescook, kstewart,
	linux-kernel, linux-media, linux-usb, mchehab, sakari.ailus,
	syzkaller-bugs, tglx

syzbot has found a reproducer for 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=11e19043a00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f6d4561982f71f63
dashboard link: https://syzkaller.appspot.com/bug?extid=0c90fc937c84f97d0aa6
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=147d42eda00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=104c268ba00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0c90fc937c84f97d0aa6@syzkaller.appspotmail.com

cpia2: Message: count = 1, register[0] = 0x0
cpia2: Unexpected error: -19
==================================================================
BUG: KASAN: use-after-free in cpia2_usb_disconnect+0x1a4/0x1c0  
drivers/media/usb/cpia2/cpia2_usb.c:898
Read of size 8 at addr ffff8881cf6c4e50 by task kworker/1:1/22

CPU: 1 PID: 22 Comm: kworker/1:1 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
  cpia2_usb_disconnect+0x1a4/0x1c0 drivers/media/usb/cpia2/cpia2_usb.c:898
  usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:423
  __device_release_driver drivers/base/dd.c:1081 [inline]
  device_release_driver_internal+0x404/0x4c0 drivers/base/dd.c:1112
  bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:556
  device_del+0x460/0xb80 drivers/base/core.c:2274
  usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237
  usb_disconnect+0x284/0x830 drivers/usb/core/hub.c:2197
  hub_port_connect drivers/usb/core/hub.c:4940 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
  port_event drivers/usb/core/hub.c:5350 [inline]
  hub_event+0x1409/0x3590 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

Allocated by task 22:
  save_stack+0x1b/0x80 mm/kasan/common.c:71
  set_track mm/kasan/common.c:79 [inline]
  __kasan_kmalloc mm/kasan/common.c:489 [inline]
  __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:462
  kmalloc include/linux/slab.h:547 [inline]
  kzalloc include/linux/slab.h:742 [inline]
  cpia2_init_camera_struct+0x40/0x110  
drivers/media/usb/cpia2/cpia2_core.c:2176
  cpia2_usb_probe.cold+0x37/0x45a drivers/media/usb/cpia2/cpia2_usb.c:833
  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
  worker_thread+0x96/0xe20 kernel/workqueue.c:2415
  kthread+0x30b/0x410 kernel/kthread.c:255
  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 22:
  save_stack+0x1b/0x80 mm/kasan/common.c:71
  set_track mm/kasan/common.c:79 [inline]
  __kasan_slab_free+0x130/0x180 mm/kasan/common.c:451
  slab_free_hook mm/slub.c:1421 [inline]
  slab_free_freelist_hook mm/slub.c:1448 [inline]
  slab_free mm/slub.c:2994 [inline]
  kfree+0xd7/0x280 mm/slub.c:3949
  v4l2_device_release drivers/media/v4l2-core/v4l2-device.c:55 [inline]
  kref_put include/linux/kref.h:65 [inline]
  v4l2_device_put+0x76/0x90 drivers/media/v4l2-core/v4l2-device.c:60
  cpia2_usb_disconnect+0x79/0x1c0 drivers/media/usb/cpia2/cpia2_usb.c:896
  usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:423
  __device_release_driver drivers/base/dd.c:1081 [inline]
  device_release_driver_internal+0x404/0x4c0 drivers/base/dd.c:1112
  bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:556
  device_del+0x460/0xb80 drivers/base/core.c:2274
  usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237
  usb_disconnect+0x284/0x830 drivers/usb/core/hub.c:2197
  hub_port_connect drivers/usb/core/hub.c:4940 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
  port_event drivers/usb/core/hub.c:5350 [inline]
  hub_event+0x1409/0x3590 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 object at ffff8881cf6c4400
  which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 2640 bytes inside of
  4096-byte region [ffff8881cf6c4400, ffff8881cf6c5400)
The buggy address belongs to the page:
page:ffffea00073db000 refcount:1 mapcount:0 mapping:ffff8881dac02600  
index:0x0 compound_mapcount: 0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 0000000000000000 0000000100000001 ffff8881dac02600
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8881cf6c4d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8881cf6c4d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8881cf6c4e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                  ^
  ffff8881cf6c4e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8881cf6c4f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: KASAN: use-after-free Read in cpia2_usb_disconnect
  2019-07-03  1:01 ` syzbot
@ 2019-07-03  7:42   ` Oliver Neukum
  2019-07-03 17:10     ` Eric Biggers
  0 siblings, 1 reply; 5+ messages in thread
From: Oliver Neukum @ 2019-07-03  7:42 UTC (permalink / raw)
  To: syzbot, keescook, andreyknvl, syzkaller-bugs, mchehab, tglx,
	sakari.ailus, kstewart, allison, linux-kernel, linux-media,
	linux-usb, hverkuil-cisco

Am Dienstag, den 02.07.2019, 18:01 -0700 schrieb syzbot:
> syzbot has found a reproducer for 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=11e19043a00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=f6d4561982f71f63
> dashboard link: https://syzkaller.appspot.com/bug?extid=0c90fc937c84f97d0aa6
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=147d42eda00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=104c268ba00000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+0c90fc937c84f97d0aa6@syzkaller.appspotmail.com
> 
> cpia2: Message: count = 1, register[0] = 0x0
> cpia2: Unexpected error: -19
> ==================================================================
> BUG: KASAN: use-after-free in cpia2_usb_disconnect+0x1a4/0x1c0  
> drivers/media/usb/cpia2/cpia2_usb.c:898
> Read of size 8 at addr ffff8881cf6c4e50 by task kworker/1:1/22

Please try this:

From a0a73298fc23acb95e7b6487e960be707563eb34 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@suse.com>
Date: Wed, 8 May 2019 12:36:40 +0200
Subject: [PATCH] cpia2_usb: first wake up, then free in disconnect

Kasan reported a use after free in cpia2_usb_disconnect()
It first freed everything and then woke up those waiting.
The reverse order is correct.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reported-by: syzbot+0c90fc937c84f97d0aa6@syzkaller.appspotmail.com
Fixes: 6c493f8b28c67 ("[media] cpia2: major overhaul to get it in a working state again")
---
 drivers/media/usb/cpia2/cpia2_usb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/cpia2/cpia2_usb.c b/drivers/media/usb/cpia2/cpia2_usb.c
index e5d8dee38fe4..44bd7e5ad3eb 100644
--- a/drivers/media/usb/cpia2/cpia2_usb.c
+++ b/drivers/media/usb/cpia2/cpia2_usb.c
@@ -902,7 +902,6 @@ static void cpia2_usb_disconnect(struct usb_interface *intf)
 	cpia2_unregister_camera(cam);
 	v4l2_device_disconnect(&cam->v4l2_dev);
 	mutex_unlock(&cam->v4l2_lock);
-	v4l2_device_put(&cam->v4l2_dev);
 
 	if(cam->buffers) {
 		DBG("Wakeup waiting processes\n");
@@ -911,6 +910,8 @@ static void cpia2_usb_disconnect(struct usb_interface *intf)
 		wake_up_interruptible(&cam->wq_stream);
 	}
 
+	v4l2_device_put(&cam->v4l2_dev);
+
 	LOG("CPiA2 camera disconnected.\n");
 }
 
-- 
2.16.4


^ permalink raw reply related	[flat|nested] 5+ messages in thread
* Re: KASAN: use-after-free Read in cpia2_usb_disconnect
  2019-07-03  7:42   ` Oliver Neukum
@ 2019-07-03 17:10     ` Eric Biggers
  2019-07-04  9:36       ` Oliver Neukum
  0 siblings, 1 reply; 5+ messages in thread
From: Eric Biggers @ 2019-07-03 17:10 UTC (permalink / raw)
  To: Oliver Neukum
  Cc: syzbot, keescook, andreyknvl, syzkaller-bugs, mchehab, tglx,
	sakari.ailus, kstewart, allison, linux-kernel, linux-media,
	linux-usb, hverkuil-cisco

On Wed, Jul 03, 2019 at 09:42:09AM +0200, Oliver Neukum wrote:
> Am Dienstag, den 02.07.2019, 18:01 -0700 schrieb syzbot:
> > syzbot has found a reproducer for 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=11e19043a00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=f6d4561982f71f63
> > dashboard link: https://syzkaller.appspot.com/bug?extid=0c90fc937c84f97d0aa6
> > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=147d42eda00000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=104c268ba00000
> > 
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+0c90fc937c84f97d0aa6@syzkaller.appspotmail.com
> > 
> > cpia2: Message: count = 1, register[0] = 0x0
> > cpia2: Unexpected error: -19
> > ==================================================================
> > BUG: KASAN: use-after-free in cpia2_usb_disconnect+0x1a4/0x1c0  
> > drivers/media/usb/cpia2/cpia2_usb.c:898
> > Read of size 8 at addr ffff8881cf6c4e50 by task kworker/1:1/22
> 
> Please try this:
> 
> From a0a73298fc23acb95e7b6487e960be707563eb34 Mon Sep 17 00:00:00 2001
> From: Oliver Neukum <oneukum@suse.com>
> Date: Wed, 8 May 2019 12:36:40 +0200
> Subject: [PATCH] cpia2_usb: first wake up, then free in disconnect
> 

Who are you talking to?  If you want syzbot to test your patch, follow the
directions at https://github.com/google/syzkaller/blob/master/docs/syzbot.md#testing-patches

- Eric

^ permalink raw reply	[flat|nested] 5+ messages in thread
* Re: KASAN: use-after-free Read in cpia2_usb_disconnect
  2019-07-03 17:10     ` Eric Biggers
@ 2019-07-04  9:36       ` Oliver Neukum
  0 siblings, 0 replies; 5+ messages in thread
From: Oliver Neukum @ 2019-07-04  9:36 UTC (permalink / raw)
  To: Eric Biggers
  Cc: keescook, andreyknvl, syzkaller-bugs, mchehab, tglx,
	sakari.ailus, kstewart, allison, syzbot, linux-kernel,
	linux-media, linux-usb, hverkuil-cisco

Am Mittwoch, den 03.07.2019, 10:10 -0700 schrieb Eric Biggers:
> 
> Who are you talking to?  If you want syzbot to test your patch, follow the
> directions at https://github.com/google/syzkaller/blob/master/docs/syzbot.md#testing-patches

Thanks. I am trying this out now.

	Regards
		Oliver


^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-07-04  9:36 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-04-16 11:16 KASAN: use-after-free Read in cpia2_usb_disconnect syzbot
2019-07-03  1:01 ` syzbot
2019-07-03  7:42   ` Oliver Neukum
2019-07-03 17:10     ` Eric Biggers
2019-07-04  9:36       ` Oliver Neukum

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