Subject: futex: Replace pointless printk in fixup_owner()
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue Jan 19 16:06:10 2021 +0100
Git-commit: 04b79c55201f02ffd675e1231d731365e335c307
Patch-mainline: v5.11-rc6
References: bsc#1181349 bsc#1149032 CVE-2021-3347

If that unexpected case of inconsistent arguments ever happens then the
futex state is left completely inconsistent and the printk is not really
helpful. Replace it with a warning and make the state consistent.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>

---
 kernel/futex.c |   10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2684,14 +2684,10 @@ static int fixup_owner(u32 __user *uaddr
 
 	/*
 	 * Paranoia check. If we did not take the lock, then we should not be
-	 * the owner of the rt_mutex.
+	 * the owner of the rt_mutex. Warn and establish consistent state.
 	 */
-	if (rt_mutex_owner(&q->pi_state->pi_mutex) == current) {
-		printk(KERN_ERR "fixup_owner: ret = %d pi-mutex: %p "
-				"pi-state %p\n", ret,
-				q->pi_state->pi_mutex.owner,
-				q->pi_state->owner);
-	}
+	if (WARN_ON_ONCE(rt_mutex_owner(&q->pi_state->pi_mutex) == current))
+		return fixup_pi_state_owner(uaddr, q, current);
 
 	return 0;
 }