Commit 3e423945 authored Sep 03, 2016 by Linus Torvalds

devpts: return NULL pts 'priv' entry for non-devpts nodes



In commit 8ead9dd5 ("devpts: more pty driver interface cleanups") I
made devpts_get_priv() just return the dentry->fs_data directly.  And
because I thought it wouldn't happen, I added a warning if you ever saw
a pts node that wasn't on devpts.

And no, that warning never triggered under any actual real use, but you
can trigger it by creating nonsensical pts nodes by hand.

So just revert the warning, and make devpts_get_priv() return NULL for
that case like it used to.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org # 4.6+
Cc: Eric W Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0141af18

fs/devpts/inode.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -585,7 +585,8 @@ struct dentry devpts_pty_new(struct pts_fs_info fsi, int index, void *priv)
		*/
		void devpts_get_priv(struct dentry dentry)
		{
		WARN_ON_ONCE(dentry->d_sb->s_magic != DEVPTS_SUPER_MAGIC);
		if (dentry->d_sb->s_magic != DEVPTS_SUPER_MAGIC)
		return NULL;
		return dentry->d_fsdata;
		}

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