This is a note to let you know that I've just added the patch titled
tty/n_hdlc: fix __might_sleep warning
to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From fc01d8c61ce02c034e67378cd3e645734bc18c8c Mon Sep 17 00:00:00 2001
From: Paul Fulghum paulkf@microgate.com Date: Tue, 1 Jan 2019 12:28:53 -0800 Subject: tty/n_hdlc: fix __might_sleep warning
Fix __might_sleep warning[1] 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=17d5de7f1fcab794cb8c40032f893f52de89932...
Signed-off-by: Paul Fulghum paulkf@microgate.com Reported-by: syzbot syzbot+c244af085a0159d22879@syzkaller.appspotmail.com Cc: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Cc: Alan Cox alan@lxorguk.ukuu.org.uk Cc: stable stable@vger.kernel.org Acked-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/n_hdlc.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c index 4164414d4c64..8bdf42bc8fc8 100644 --- a/drivers/tty/n_hdlc.c +++ b/drivers/tty/n_hdlc.c @@ -597,6 +597,7 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file, /* 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