From: Johan Hovold <johan@kernel.org>
To: syzbot <syzbot+66935bec147fbf68d9f8@syzkaller.appspotmail.com>
Cc: andreyknvl@google.com, gregkh@linuxfoundation.org,
legousb-devel@lists.sourceforge.net,
linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
starblue@users.sourceforge.net, syzkaller-bugs@googlegroups.com
Subject: Re: possible deadlock in tower_open
Date: Thu, 19 Sep 2019 10:23:59 +0200 [thread overview]
Message-ID: <20190919082359.GA30545@localhost> (raw)
In-Reply-To: <000000000000e669b80592ab96fc@google.com>
On Mon, Sep 16, 2019 at 06:29:12AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: f0df5c1b 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=13c8d14e600000
> kernel config: https://syzkaller.appspot.com/x/.config?x=5c6633fa4ed00be5
> dashboard link: https://syzkaller.appspot.com/bug?extid=66935bec147fbf68d9f8
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+66935bec147fbf68d9f8@syzkaller.appspotmail.com
>
> ======================================================
> WARNING: possible circular locking dependency detected
> 5.3.0-rc7+ #0 Not tainted
> ------------------------------------------------------
> syz-executor.1/8155 is trying to acquire lock:
> 0000000086c1bdfc (open_disc_mutex){+.+.}, at: tower_open+0xce/0x9b0
> drivers/usb/misc/legousbtower.c:335
>
> but task is already holding lock:
> 000000000f520f73 (minor_rwsem){++++}, at: usb_open+0x23/0x270
> drivers/usb/core/file.c:39
>
> which lock already depends on the new lock.
This looks like a duplicate of
https://lkml.kernel.org/r/000000000000d58eb90592add24e@google.com
Not sure if this is the right way to report this (quoting needed?):
#syz dup: possible deadlock in usb_deregister_dev (2)
Johan
next prev parent reply other threads:[~2019-09-19 8:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-16 13:29 possible deadlock in tower_open syzbot
2019-09-19 8:23 ` Johan Hovold [this message]
2019-09-19 13:09 ` Andrey Konovalov
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