From nobody Sun Feb 8 18:09:19 2026 Received: from cvsmtppost06.nm.naver.com (cvsmtppost06.nm.naver.com [114.111.35.101]) (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 4EB87337B8F for ; Tue, 3 Feb 2026 11:28:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.111.35.101 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770118105; cv=none; b=M4fLzSGuRy2g1PMh22MkTIcHqPXDmqScf1JKrDAUyw28lzD+dxe64k5uNJM38FrtPF/s9GjkaIXWqQn0QI5YXq/BO1joIaGYAW0+iXbyST0ltrZpDJj06B91wGd3cl1pkWxCHAoBuCfOkNGPUlxdIV1SqC++iqAMXvisghVUBQQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770118105; c=relaxed/simple; bh=EuNLaHfH5LJWPJaic7aqjD5pcArbN1+ZuPnkHZ2XDug=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=DRYEpFDZO8amvUSvIV0RsFLmE6agU6Findd8f7o1VLs3jb9mKrrzjkKFA7vMabJ9qTP5uja81F9wB7m3F4P6fvAT5pfc8KmFMm2bLYNuUkbrKnVBOi/R81zudwJRImYbzWoZxg8GA/00QSpFblX/llQVS58VdkgcpUzLm3mIQjs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=naver.com; spf=pass smtp.mailfrom=naver.com; dkim=pass (2048-bit key) header.d=naver.com header.i=@naver.com header.b=El7QtPf/; arc=none smtp.client-ip=114.111.35.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=naver.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=naver.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=naver.com header.i=@naver.com header.b="El7QtPf/" Received: from cvsendbo014.nm ([10.112.20.45]) by cvsmtppost06.nm.naver.com with ESMTP id mVhCAjoyRdy+oIept-pERQ for ; Tue, 03 Feb 2026 11:28:13 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=naver.com; s=s20171208; t=1770118093; bh=EuNLaHfH5LJWPJaic7aqjD5pcArbN1+ZuPnkHZ2XDug=; h=From:To:Subject:Date:Message-ID:From:Subject:Feedback-ID: X-Works-Security; b=El7QtPf//sAVUAR9XzRQBRJui3943nxCj0PQKBKea2zLa+i8Zlsc2aeLeHyOrOyDZ UoXOmzq7YxoRwhLHWrPh/hssvPxGCsxOAoTBSdrqrKbHDuRcejdGOI+Cq2cORcBLz7 /RO+zFS8d7IECOhLjeskFsRbmzv/8p4N/rGVRjslL5OGy0q0/Qn0+0TzBbAPMqBjtR pnJJxcJQpwziY2Oy6wAAZrOBIBudowCmi79gvrjtyLJKRHPFvgrdTVxKZlhvc1qszR pD9gT2mk2Al1olgHKiS0b8gUFEqlzm5cOJXp7FR8Dz652jrJvGJktofGOctg8FlXTm 8cfy0IvPApY6A== X-Session-ID: z3XcyRXtQGiXR3bR-ow6tw X-Works-Send-Opt: M/YXjAJYjHmwKo2qKqJYFquqFNwkx0eFjAJYKg== X-Works-Smtp-Source: Xdn/KAgXFqJZ+HmZaxM9+6E= Received: from JMW-Ubuntu.. ([14.38.141.199]) by cvnsmtp012.nm.naver.com with ESMTP id z3XcyRXtQGiXR3bR-ow6tw for (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384); Tue, 03 Feb 2026 11:28:12 -0000 From: Minu Jin To: parthiban.veerasooran@microchip.com, christian.gromm@microchip.com, gregkh@linuxfoundation.org Cc: hverkuil+cisco@kernel.org, laurent.pinchart+renesas@ideasonboard.com, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, Minu Jin Subject: [PATCH] staging: most: video: fix potential race in list iteration Date: Tue, 3 Feb 2026 20:28:00 +0900 Message-ID: <20260203112800.3351763-1-s9430939@naver.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" There is a pattern in the loops where the lock is dropped to call a specific function and then re-acquired. The list can be exposed during this short gap, creating a potential race condition. This patch fixes the problem by moving nodes to a local list while holding the lock, instead of using the unlock/lock pattern in the loop. Signed-off-by: Minu Jin --- drivers/staging/most/video/video.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/staging/most/video/video.c b/drivers/staging/most/vide= o/video.c index 32f71d9a9cf7..e7db58e5746a 100644 --- a/drivers/staging/most/video/video.c +++ b/drivers/staging/most/video/video.c @@ -121,6 +121,7 @@ static int comp_vdev_close(struct file *filp) struct comp_fh *fh =3D to_comp_fh(filp); struct most_video_dev *mdev =3D fh->mdev; struct mbo *mbo, *tmp; + LIST_HEAD(free_list); =20 /* * We need to put MBOs back before we call most_stop_channel() @@ -134,12 +135,15 @@ static int comp_vdev_close(struct file *filp) spin_lock_irq(&mdev->list_lock); mdev->mute =3D true; list_for_each_entry_safe(mbo, tmp, &mdev->pending_mbos, list) { - list_del(&mbo->list); - spin_unlock_irq(&mdev->list_lock); - most_put_mbo(mbo); - spin_lock_irq(&mdev->list_lock); + list_move(&mbo->list, &free_list); } spin_unlock_irq(&mdev->list_lock); + + list_for_each_entry_safe(mbo, tmp, &free_list, list) { + list_del_init(&mbo->list); + most_put_mbo(mbo); + } + most_stop_channel(mdev->iface, mdev->ch_idx, &comp); mdev->mute =3D false; =20 @@ -554,6 +558,7 @@ static int __init comp_init(void) static void __exit comp_exit(void) { struct most_video_dev *mdev, *tmp; + LIST_HEAD(free_list); =20 /* * As the mostcore currently doesn't call disconnect_channel() @@ -563,15 +568,16 @@ static void __exit comp_exit(void) */ spin_lock_irq(&list_lock); list_for_each_entry_safe(mdev, tmp, &video_devices, list) { - list_del(&mdev->list); - spin_unlock_irq(&list_lock); + list_move(&mdev->list, &free_list); + } + spin_unlock_irq(&list_lock); =20 + list_for_each_entry_safe(mdev, tmp, &free_list, list) { + list_del_init(&mdev->list); comp_unregister_videodev(mdev); v4l2_device_disconnect(&mdev->v4l2_dev); v4l2_device_put(&mdev->v4l2_dev); - spin_lock_irq(&list_lock); } - spin_unlock_irq(&list_lock); =20 most_deregister_configfs_subsys(&comp); most_deregister_component(&comp); --=20 2.43.0