From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794062943; b=VjVj1oK4RU9xqi+SbQfODz+rD75fTdYzny2qrt8FpMd43TNclyRf9roxfZ8564jFJI6H UEqmf+Leq6OfQbVMKLyexl7wkLGthXjRqC3Im2ef64/u1DUqkrgkzz+vFFe96MMuicZ/Y +bMnzJZhh3ul0NVuHgEVXMg2ew25KXJzQdXsda7DJyo6G3z8aZzdWBtczPRBLxEa8svp1 jM0CbNfV4Nai40xrmk/jiB3WAlr9Fsr2GNy9ByU/ywqWRYCaCIEuWhKigcchSRRvdRNSu itTcr4kk5fjrwjUoyQ1WU0ITZT5Wzsg7dYtMjq15RYtI1aGZrYQhienD6awhPj0OECw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794062943; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=Lo8uZVLGLtyxZLrX225UsHdS3nPHnrvP1rF1awii4Jk=; b=ozG9SpXsevEIgYzUFo6SkSpqBaxOYpylTYfpqAhsSAsbWSWxy2LnGDykoQKKGiJowsX+ Hh3fg/JQZwx+jXJ46TtnGCKxa1PH/nA8Vo7yhKWGUfljUysNS+80OZdjoTQZ0xqAx6Ujn URrm93ag93nPviW7bmffujgPEnQqleB2NtUNe3ikb0tb0YnNWpCnJoKb/H9qZqnsbSjNN SuPHv74Rwh13qp9qUH+LiYfAkab/qAkF+ci+RH9gXOqucqO/QGr5uO3wYo+452ZK/VEdP jFMNrn1opKllDXBu0WCKVpgS0Ren3evWsd5SjnrlIrQxvMXj282/V3r0mJifg/dqxVw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="d/hUKeO5"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B6495606A33E; Sat, 7 Nov 2026 14:49:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=d/hUKeO5 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D04A1F0089F; Sat, 7 Nov 2026 14:49:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794062942; bh=Lo8uZVLGLtyxZLrX225UsHdS3nPHnrvP1rF1awii4Jk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=d/hUKeO5xKNzPnLMyXOmZoYs+3SzuJqxFdKKFXWPDK/DJwadOL00HZxTOC8Cgf1AF GTzTManYIpnDWQxO3p+wK9MWbh4gOdMvAa+IbMDHbOF5aUgEG4yQ5EDsXfGzFZo3bd wyj73ImAm4VbEkQFiFsijKdGT801iOIdlcZvv54k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+cf896de36144391bcde1@syzkaller.appspotmail.com, Hans Verkuil , Rohinthan P , Hans Verkuil , Sasha Levin Subject: [PATCH 6.18 209/869] media: v4l2-ctrls: do nothing if controls[0] == NULL in cluster functions Date: Sat, 7 Nov 2026 08:48:11 -0500 Message-ID: <20261107134859.060229637@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rohinthan P [ Upstream commit 9ff738f93084351ed6e818d4d58679a9e9083a8d ] The V4L2 control framework is designed to allow drivers to instantiate controls and clusters without checking for errors after each call, checking hdl->error only once at the end. However, if allocating the master control (controls[0]) fails, e.g. due to memory allocation failure, v4l2_ctrl_cluster() triggers a WARNING: ncontrols == 0 || controls[0] == NULL WARNING: drivers/media/v4l2-core/v4l2-ctrls-core.c:2525 at v4l2_ctrl_cluster Additionally, v4l2_ctrl_auto_cluster() attempts to dereference master->minimum without checking if controls[0] is NULL, leading to a NULL pointer dereference when master control creation fails. Update both v4l2_ctrl_cluster() and v4l2_ctrl_auto_cluster() to silently return if controls[0] is NULL, preserving the design that control creation errors are caught at the end when the driver checks hdl->error. Also update function documentation in include/media/v4l2-ctrls.h. Fixes: 71c689dc2e73 ("media: v4l2-ctrls: split up into four source files") Cc: stable@vger.kernel.org Reported-by: syzbot+cf896de36144391bcde1@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=cf896de36144391bcde1 Suggested-by: Hans Verkuil Signed-off-by: Rohinthan P Signed-off-by: Hans Verkuil [hverkuil: simplified the v4l2_ctrl_auto_cluster code a bit] Signed-off-by: Sasha Levin --- drivers/media/v4l2-core/v4l2-ctrls-core.c | 12 ++++++++++-- include/media/v4l2-ctrls.h | 6 ++++++ 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c index 02e2ae93d1764..579787f0be351 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c @@ -2431,7 +2431,10 @@ void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls) int i; /* The first control is the master control and it must not be NULL */ - if (WARN_ON(ncontrols == 0 || controls[0] == NULL)) + if (WARN_ON(ncontrols == 0)) + return; + + if (!controls[0]) return; for (i = 0; i < ncontrols; i++) { @@ -2453,8 +2456,13 @@ void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls, u32 flag = 0; int i; + if (WARN_ON(ncontrols <= 1)) + return; + + if (!master) + return; + v4l2_ctrl_cluster(ncontrols, controls); - WARN_ON(ncontrols <= 1); WARN_ON(manual_val < master->minimum || manual_val > master->maximum); WARN_ON(set_volatile && !has_op(master, g_volatile_ctrl)); master->is_auto = true; diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h index 31fc1bee3797b..b900734ee9c1c 100644 --- a/include/media/v4l2-ctrls.h +++ b/include/media/v4l2-ctrls.h @@ -834,6 +834,9 @@ bool v4l2_ctrl_radio_filter(const struct v4l2_ctrl *ctrl); * * @ncontrols: The number of controls in this cluster. * @controls: The cluster control array of size @ncontrols. + * + * If controls[0] is NULL, then this function does nothing and just + * returns. */ void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls); @@ -845,6 +848,9 @@ void v4l2_ctrl_cluster(unsigned int ncontrols, struct v4l2_ctrl **controls); * @ncontrols: The number of controls in this cluster. * @controls: The cluster control array of size @ncontrols. The first control * must be the 'auto' control (e.g. autogain, autoexposure, etc.) + * + * If controls[0] is NULL, then this function does nothing and just + * returns. * @manual_val: The value for the first control in the cluster that equals the * manual setting. * @set_volatile: If true, then all controls except the first auto control will -- 2.53.0