From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1CFF9471249; Sat, 12 Sep 2026 15:52:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789228334; cv=none; b=hJevuEAUpzT6/gBZ/O+IpGylQtYmMJnAtqknT6OP0q7JiUkio9LId2lkQRC1ul5HrGcN3BIzz8eSc0lEfzHsg5vOYly6JPAKFqyjhU3K4E3Xg49Yj7uzBprOJZY967F9bcEfXoQ8stmR2XuOrIIbINMXQx0Hhm6cZGfQzxLIroE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789228334; c=relaxed/simple; bh=/1nqz6sZIM9kGLfjBOJcOQ9uI29xxYMfJszVMIGColA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HJ1C2XnPwyPYlc5nAHs5J9mifYDU9NcQPe82w9IAwoI1IiRYxHToBe8jqB5mYSn6AJPK6mBwtpKmpkhMGqV57Rk4VJdOKci2s3cTN348BunHAyvQ3oKHqFPMF+MzUDIc0KH8Tjp7zzzaMZjFWzM+UR9vNjr6wtW8O4aIxeXxrvY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nlNEL+WA; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nlNEL+WA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4BFC1F000FF; Sat, 12 Sep 2026 15:52:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789228333; bh=mu0hXInKvNKrQofHfcgf5/4Dto2F4xB0pW8gyqhLhdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nlNEL+WAwiLkuHH/Dt5w5+JucrYaI0u/hsN3fN4rx5xZbDcTlqG9/SUFPqdmg8/rR k12qWerOMc35TSO+clEdhhojQ/MszfCoyb5XBHCmNBkTEF3JbpQXBl5r4w5MHmYWao TnRUui0YNVq9MfcY2GC45UlII69Djw+itr0CrVGk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ruoyu Wang , Hans Verkuil Subject: [PATCH 6.1 0363/1191] media: cec: Serialize exclusive follower delivery Date: Sat, 12 Sep 2026 08:51:31 +0200 Message-ID: <20260912065556.381406906@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065548.086904252@linuxfoundation.org> References: <20260912065548.086904252@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ruoyu Wang commit 1924d0788caa6c66fd320dd4704fae99487fd2c7 upstream. cec_receive_notify() reads the exclusive follower pointer without the adapter lock. Serialize the no-follower check and message delivery against mode changes and release. Fixes: 9881fe0ca187 ("[media] cec: add HDMI CEC framework (adapter)") Cc: stable@vger.kernel.org Signed-off-by: Ruoyu Wang Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman --- drivers/media/cec/core/cec-adap.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/media/cec/core/cec-adap.c +++ b/drivers/media/cec/core/cec-adap.c @@ -2152,9 +2152,13 @@ static int cec_receive_notify(struct cec * Unprocessed messages are aborted if userspace isn't doing * any processing either. */ + mutex_lock(&adap->lock); if (!is_broadcast && !is_reply && !adap->follower_cnt && - !adap->cec_follower && msg->msg[1] != CEC_MSG_FEATURE_ABORT) + !adap->cec_follower && msg->msg[1] != CEC_MSG_FEATURE_ABORT) { + mutex_unlock(&adap->lock); return cec_feature_abort(adap, msg); + } + mutex_unlock(&adap->lock); break; } @@ -2167,10 +2171,12 @@ skip_processing: * Send to the exclusive follower if there is one, otherwise send * to all followers. */ + mutex_lock(&adap->lock); if (adap->cec_follower) cec_queue_msg_fh(adap->cec_follower, msg); else cec_queue_msg_followers(adap, msg); + mutex_unlock(&adap->lock); return 0; }