[PATCH][next] futex: fix assigned ret variable that is never read

From: Colin King <colin.king@canonical.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Darren Hart <dvhart@infradead.org>,
	Davidlohr Bueso <dave@stgolabs.net>
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH][next] futex: fix assigned ret variable that is never read
Date: Wed, 18 Aug 2021 14:18:40 +0100	[thread overview]
Message-ID: <20210818131840.34262-1-colin.king@canonical.com> (raw)

From: Colin Ian King <colin.king@canonical.com>

Currently the check on the rt_waiter and top_waiter->pi_state is
assigning an error return code to ret but this later gets re-assigned,
hence the check is currently ineffective. I believe the original
intent was to return -EINVAL rather than assign it to ret. Fix this.

Addresses-Coverity: ("Unused value")
Fixes: dc7109aaa233 ("futex: Validate waiter correctly in futex_proxy_trylock_atomic()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 kernel/futex.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index e7b4c6121da4..30e7daebaec8 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2025,7 +2025,7 @@ futex_proxy_trylock_atomic(u32 __user *pifutex, struct futex_hash_bucket *hb1,
 	 * and waiting on the 'waitqueue' futex which is always !PI.
 	 */
 	if (!top_waiter->rt_waiter || top_waiter->pi_state)
-		ret = -EINVAL;
+		return -EINVAL;
 
 	/* Ensure we requeue to the expected futex. */
 	if (!match_futex(top_waiter->requeue_pi_key, key2))
-- 
2.32.0

