From: Alan Stern <stern@rowland.harvard.edu>
To: syzbot <syzbot+ada0f7d3d9fd2016d927@syzkaller.appspotmail.com>
Cc: gregkh@linuxfoundation.org, johan@kernel.org,
linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
mathias.nyman@linux.intel.com, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] INFO: task hung in do_proc_bulk
Date: Sat, 28 Aug 2021 14:03:58 -0400 [thread overview]
Message-ID: <20210828180358.GA291431@rowland.harvard.edu> (raw)
In-Reply-To: <000000000000a83c6a05caa09572@google.com>
On Sat, Aug 28, 2021 at 08:52:17AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: d5ae8d7f85b7 Revert "media: dvb header files: move some he..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=155fa21e300000
> kernel config: https://syzkaller.appspot.com/x/.config?x=2fd902af77ff1e56
> dashboard link: https://syzkaller.appspot.com/bug?extid=ada0f7d3d9fd2016d927
> compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11a1ab0e300000
>
> Bisection is inconclusive: the issue happens on the oldest tested release.
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15662ee1300000
> final oops: https://syzkaller.appspot.com/x/report.txt?x=17662ee1300000
> console output: https://syzkaller.appspot.com/x/log.txt?x=13662ee1300000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+ada0f7d3d9fd2016d927@syzkaller.appspotmail.com
>
> INFO: task syz-executor.0:8700 blocked for more than 143 seconds.
> Not tainted 5.14.0-rc7-syzkaller #0
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> task:syz-executor.0 state:D stack:23192 pid: 8700 ppid: 8455 flags:0x00004004
> Call Trace:
> context_switch kernel/sched/core.c:4681 [inline]
> __schedule+0xc07/0x11f0 kernel/sched/core.c:5938
> schedule+0x14b/0x210 kernel/sched/core.c:6017
> schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1857
> do_wait_for_common+0x2da/0x480 kernel/sched/completion.c:85
> __wait_for_common kernel/sched/completion.c:106 [inline]
> wait_for_common kernel/sched/completion.c:117 [inline]
> wait_for_completion_timeout+0x46/0x60 kernel/sched/completion.c:157
> usb_start_wait_urb+0x167/0x550 drivers/usb/core/message.c:63
> do_proc_bulk+0x978/0x1080 drivers/usb/core/devio.c:1236
Looks like the wait needs to be interruptible.
Alan Stern
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git d5ae8d7f85b7
Index: usb-devel/drivers/usb/core/message.c
===================================================================
--- usb-devel.orig/drivers/usb/core/message.c
+++ usb-devel/drivers/usb/core/message.c
@@ -60,12 +60,18 @@ static int usb_start_wait_urb(struct urb
goto out;
expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT;
- if (!wait_for_completion_timeout(&ctx.done, expire)) {
+ retval = wait_for_completion_interruptible_timeout(&ctx.done, expire);
+ if (retval <= 0) {
usb_kill_urb(urb);
- retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
+ if (retval < 0)
+ retval = -EINTR;
+ else if (ctx.status == -ENOENT)
+ retval = -ETIMEDOUT;
+ else
+ retval = ctx.status;
dev_dbg(&urb->dev->dev,
- "%s timed out on ep%d%s len=%u/%u\n",
+ "%s timed out or interrupted on ep%d%s len=%u/%u\n",
current->comm,
usb_endpoint_num(&urb->ep->desc),
usb_urb_dir_in(urb) ? "in" : "out",
next prev parent reply other threads:[~2021-08-28 18:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-28 15:52 [syzbot] INFO: task hung in do_proc_bulk syzbot
2021-08-28 18:03 ` Alan Stern [this message]
2021-08-28 20:05 ` syzbot
2021-08-29 1:58 ` [PATCH] USB: core: Make usb_start_wait_urb() interruptible Alan Stern
2021-08-30 7:56 ` Johan Hovold
2021-08-30 14:46 ` Alan Stern
2021-08-30 15:11 ` Oliver Neukum
2021-08-30 16:09 ` Alan Stern
2021-08-31 8:52 ` Oliver Neukum
2021-08-31 9:13 ` Johan Hovold
2021-08-31 10:47 ` Oliver Neukum
2021-08-31 11:02 ` Oliver Neukum
2021-08-31 11:10 ` Johan Hovold
2021-08-31 17:03 ` Alan Stern
2021-09-01 8:16 ` Oliver Neukum
2021-09-02 20:04 ` [syzbot] INFO: task hung in do_proc_bulk Alan Stern
2021-09-02 20:46 ` syzbot
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