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@xxxxxxxxxxxxxxxxxxxxxxxxx > > 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",
