WARNING: ODEBUG bug in input_ff_destroy

WARNING: ODEBUG bug in input_ff_destroy

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    3183c037 usb: gadget: add raw-gadget interface
git tree:       https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=17cf5e72e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=79de80330003b5f7
dashboard link: https://syzkaller.appspot.com/bug?extid=b6c55daa701fc389e286
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10b4e53ae00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1173fe72e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+b6c55daa701fc389e286@syzkaller.appspotmail.com

------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint:  
ml_effect_timer+0x0/0x70 drivers/input/ff-memless.c:421
WARNING: CPU: 0 PID: 1918 at lib/debugobjects.c:481  
debug_print_object+0x160/0x250 lib/debugobjects.c:481
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 1918 Comm: syz-executor941 Not tainted 5.4.0-rc6+ #0
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+0xca/0x13e lib/dump_stack.c:113
  panic+0x2aa/0x6e1 kernel/panic.c:221
  __warn.cold+0x2f/0x33 kernel/panic.c:582
  report_bug+0x27b/0x2f0 lib/bug.c:195
  fixup_bug arch/x86/kernel/traps.c:179 [inline]
  fixup_bug arch/x86/kernel/traps.c:174 [inline]
  do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:272
  do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:291
  invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:debug_print_object+0x160/0x250 lib/debugobjects.c:481
Code: dd 00 c8 da 85 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 bf 00 00 00 48  
8b 14 dd 00 c8 da 85 48 c7 c7 a0 bd da 85 e8 25 15 30 ff <0f> 0b 83 05 9b  
bd a2 05 01 48 83 c4 20 5b 5d 41 5c 41 5d c3 48 89
RSP: 0018:ffff8881d731f738 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8128c9cd RDI: ffffed103ae63ed9
RBP: 0000000000000001 R08: ffff8881d23bc800 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff86d0b500
R13: ffffffff812ed560 R14: ffff8881cfb18310 R15: ffff8881ca291d90
  __debug_check_no_obj_freed lib/debugobjects.c:963 [inline]
  debug_check_no_obj_freed+0x2df/0x443 lib/debugobjects.c:994
  slab_free_hook mm/slub.c:1421 [inline]
  slab_free_freelist_hook mm/slub.c:1475 [inline]
  slab_free mm/slub.c:3025 [inline]
  kfree+0x20b/0x320 mm/slub.c:3977
  input_ff_destroy+0xb9/0x150 drivers/input/ff-core.c:373
  input_dev_release+0x19/0xd0 drivers/input/input.c:1537
  device_release+0x71/0x200 drivers/base/core.c:1101
  kobject_cleanup lib/kobject.c:693 [inline]
  kobject_release lib/kobject.c:722 [inline]
  kref_put include/linux/kref.h:65 [inline]
  kobject_put+0x171/0x280 lib/kobject.c:739
  put_device+0x1b/0x30 drivers/base/core.c:2301
  input_put_device include/linux/input.h:363 [inline]
  evdev_free+0x4c/0x70 drivers/input/evdev.c:347
  device_release+0x71/0x200 drivers/base/core.c:1101
  kobject_cleanup lib/kobject.c:693 [inline]
  kobject_release lib/kobject.c:722 [inline]
  kref_put include/linux/kref.h:65 [inline]
  kobject_put+0x171/0x280 lib/kobject.c:739
  kobject_cleanup lib/kobject.c:693 [inline]
  kobject_release lib/kobject.c:722 [inline]
  kref_put include/linux/kref.h:65 [inline]
  kobject_put+0x171/0x280 lib/kobject.c:739
  cdev_put.part.0+0x32/0x50 fs/char_dev.c:365
  cdev_put fs/char_dev.c:363 [inline]
  chrdev_open+0x296/0x5c0 fs/char_dev.c:422
  do_dentry_open+0x494/0x1120 fs/open.c:797
  do_last fs/namei.c:3408 [inline]
  path_openat+0x1430/0x3ff0 fs/namei.c:3525
  do_filp_open+0x1a1/0x280 fs/namei.c:3555
  do_sys_open+0x3c0/0x580 fs/open.c:1097
  do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x402000
Code: 01 f0 ff ff 0f 83 40 0e 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f  
44 00 00 83 3d 6d 84 2d 00 00 75 14 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 14 0e 00 00 c3 48 83 ec 08 e8 7a 03 00 00
RSP: 002b:00007ffff4b02e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000402000
RDX: 0000000000000000 RSI: 000000000000107d RDI: 00007ffff4b02f00
RBP: 000000000000d9d1 R08: 00007ffff4b02e60 R09: 000000000000d9d1
R10: 00007ffff4b02e60 R11: 0000000000000246 R12: 00000000004032a0
R13: 0000000000403330 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
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Re: WARNING: ODEBUG bug in input_ff_destroy

[Oliver Neukum]

Am Mittwoch, den 13.11.2019, 04:35 -0800 schrieb syzbot:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    3183c037 usb: gadget: add raw-gadget interface
> git tree:       https://github.com/google/kasan.git usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=17cf5e72e00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=79de80330003b5f7
> dashboard link: https://syzkaller.appspot.com/bug?extid=b6c55daa701fc389e286
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10b4e53ae00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1173fe72e00000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+b6c55daa701fc389e286@syzkaller.appspotmail.com

#syz test: https://github.com/google/kasan.git 3183c037

asix: fix information leak on short answersFrom b72ba3305d1e0405bfff5b6fc936d3769cd46c42 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@suse.com>
Date: Thu, 14 Nov 2019 11:03:45 +0100
Subject: [PATCH] ff-memless: kill timer in destroy()

No timer must be left running when the device goes away.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/input/ff-memless.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/input/ff-memless.c b/drivers/input/ff-memless.c
index 1cb40c7475af..e72543d831cd 100644
--- a/drivers/input/ff-memless.c
+++ b/drivers/input/ff-memless.c
@@ -489,6 +489,7 @@ static void ml_ff_destroy(struct ff_device *ff)
 {
 	struct ml_device *ml = ff->private;
 
+	del_timer_sync(&ml->timer);
 	kfree(ml->private);
 }
 
-- 
2.16.4

Re: WARNING: ODEBUG bug in input_ff_destroy

[syzbot]

Hello,

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

Reported-and-tested-by:  
syzbot+b6c55daa701fc389e286@syzkaller.appspotmail.com

Tested on:

commit:         3183c037 usb: gadget: add raw-gadget interface
git tree:       https://github.com/google/kasan.git
kernel config:  https://syzkaller.appspot.com/x/.config?x=79de80330003b5f7
dashboard link: https://syzkaller.appspot.com/bug?extid=b6c55daa701fc389e286
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12c2e254e00000

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