patch "tty/n_hdlc: fix __might_sleep warning" added to tty-linus

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 <[email protected]>
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=17d5de7f1fcab794cb8c40032f893f52de899324

---
 drivers/tty/n_hdlc.c | 1 +
 1 file changed, 1 insertion(+)

index 4164414d4c64..8bdf42bc8fc8 100644
@@ -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

2.20.1