Messages in this thread | | | Subject | Re: [PATCH] tty/n_hdlc: fix __might_sleep warning | From | Tetsuo Handa <> | Date | Thu, 10 Jan 2019 20:38:33 +0900 |
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Hello, Greg.
We attempted a cleanup but we failed. Thus, will you apply this patch for now?
On 2019/01/02 5:28, Paul Fulghum wrote: > Fix __might_sleep warning in tty/n_hdlc.c read due to copy_to_user call while current is TASK_INTERRUPTIBLE. > This is a false positive since the code path does not depend on current state remaining TASK_INTERRUPTIBLE. > The loop breaks out and sets TASK_RUNNING after calling copy_to_user. > This patch supresses the warning by setting TASK_RUNNING before calling copy_to_user. > > [1] https://syzkaller.appspot.com/bug?id=17d5de7f1fcab794cb8c40032f893f52de899324 > > Signed-off-by: Paul Fulghum <paulkf@microgate.com> > Reported-by: syzbot <syzbot+c244af085a0159d22879@syzkaller.appspotmail.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> > — > --- a/drivers/tty/n_hdlc.c 2018-12-23 15:55:59.000000000 -0800 > +++ b/drivers/tty/n_hdlc.c 2019-01-01 11:44:47.148153954 -0800 > @@ -597,6 +597,7 @@ static ssize_t n_hdlc_tty_read(struct tt > /* too large for caller's buffer */ > ret = -EOVERFLOW; > } else { > + __set_current_state(TASK_RUNNING); > if (copy_to_user(buf, rbuf->buf, rbuf->count)) > ret = -EFAULT; > else
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