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Date:   Sat, 28 May 2022 10:02:12 -0700
In-Reply-To: <YpJNQN6++raKTXS5@rowland.harvard.edu>
Message-ID: <0000000000005b7a1b05e0156265@google.com>
Subject: Re: [syzbot] WARNING in driver_unregister
From:   syzbot <syzbot+02b16343704b3af1667e@syzkaller.appspotmail.com>
To:     andreyknvl@gmail.com, gregkh@linuxfoundation.org,
        linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
        stern@rowland.harvard.edu, syzkaller-bugs@googlegroups.com
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Precedence: bulk

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in driver_unregister

------------[ cut here ]------------
Unexpected driver unregister!
WARNING: CPU: 0 PID: 2335 at drivers/base/driver.c:194 driver_unregister drivers/base/driver.c:194 [inline]
WARNING: CPU: 0 PID: 2335 at drivers/base/driver.c:194 driver_unregister+0x8c/0xb0 drivers/base/driver.c:191
Modules linked in:
CPU: 0 PID: 2335 Comm: syz-executor.0 Not tainted 5.18.0-rc5-syzkaller-00157-g97fa5887cf28-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:driver_unregister drivers/base/driver.c:194 [inline]
RIP: 0010:driver_unregister+0x8c/0xb0 drivers/base/driver.c:191
Code: 68 4c 89 e7 e8 65 b9 db fe 48 89 ef e8 fd a0 ff ff 5d 41 5c e9 75 fa 78 fe e8 70 fa 78 fe 48 c7 c7 80 7a 81 86 e8 12 96 ee 02 <0f> 0b 5d 41 5c e9 5a fa 78 fe e8 75 93 ad fe eb 96 e8 6e 93 ad fe
RSP: 0018:ffffc9000267fa78 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888118006050 RCX: 0000000000000000
RDX: ffff888114fe8000 RSI: ffffffff812bdce8 RDI: fffff520004cff41
RBP: ffff888118006098 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff812b86be R11: 0000000000000000 R12: 0000000000000000
R13: ffff888118006008 R14: ffff88811785e7a8 R15: ffff888100219ca0
FS:  0000000000000000(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc6f40b3718 CR3: 0000000007825000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 usb_gadget_unregister_driver+0x48/0x70 drivers/usb/gadget/udc/core.c:1590
 raw_release+0x18b/0x290 drivers/usb/gadget/legacy/raw_gadget.c:412
 __fput+0x277/0x9d0 fs/file_table.c:317
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:37 [inline]
 do_exit+0xaff/0x2980 kernel/exit.c:795
 do_group_exit+0xd2/0x2f0 kernel/exit.c:925
 get_signal+0x22df/0x24c0 kernel/signal.c:2864
 arch_do_signal_or_restart+0x82/0x20f0 arch/x86/kernel/signal.c:867
 exit_to_user_mode_loop kernel/entry/common.c:166 [inline]
 exit_to_user_mode_prepare+0x156/0x200 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:294
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc6f417f0e9
Code: Unable to access opcode bytes at RIP 0x7fc6f417f0bf.
RSP: 002b:00007fc6f40b3218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fc6f4292108 RCX: 00007fc6f417f0e9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc6f4292108
RBP: 00007fc6f4292100 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc6f429210c
R13: 00007ffd64cd846f R14: 00007fc6f40b3300 R15: 0000000000022000
 </TASK>


Tested on:

commit:         97fa5887 USB: new quirk for Dell Gen 2 devices
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
console output: https://syzkaller.appspot.com/x/log.txt?x=16effa13f00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d7b232ec3adf5c8d
dashboard link: https://syzkaller.appspot.com/bug?extid=02b16343704b3af1667e
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13e750ddf00000