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 CF2A3430CE5 for ; Mon, 24 Aug 2026 14:05:57 +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=1787580359; cv=none; b=jJO9nhS3BboSpQWOZgiP8vvBmXh/QlxGdl4G6zyAVu8aLpLlwF/Eu98wTb5YbSIXnvIrFqCJuWOtMyK6zr/PIBzzaM+19ApYH3822M4AYUIdnbpyXeOBJ5C6ZYQ66gO/J6E8a/CWPAYrSNdgLYC0OdROqyQvqFkowA4/R5lCad4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787580359; c=relaxed/simple; bh=3dX5246dOzqwp3sEuhvLB2fojLIW6KOzR4g6fIOpJK4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Z4Nka1hsj2PB1Wevnmgtw+NJkxbjLCYjNruYC2jcfyyyaJgGoDvfnK4xyxiT+V4F3RmC1gPOYuB3r1BE3smrhN7EG6Dw4xL0onQM3V++k+Qg0vJyfMeLzt1dpROxTpziJzGwQTK0ufFexgpd9/N/MPY5wMOhlG/su3fb8OrJIVA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cN0rY1qB; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cN0rY1qB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE2C11F000E9; Mon, 24 Aug 2026 14:05:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787580357; bh=KM/twUv/vmRfGRkU1zENS1631BIYFqw2Kb3MyPSDeFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cN0rY1qBwT6PO2/wGs0mOrJZGU/tFvBd6YZebtuVL8A+/2vEJb+FVcTeLG4F/tHIx nLoIg1CcLQBAB53mWVz+PtEBqChI5EswQ1fSyzx8X1ZM0HWTE+q5snA2WQx6viKcU6 AFErSoMgwuxri/VvtA9LhiQREWtdiPV6Rjo+QGsfKLDLbZbYq43SSTJGHItmMwVfJK 6AnmkwbNJOqmuFi9e1iBevwgWNZJisjxSDsNcVm6MufZNOEnlFo8S3B5REFlccS8Mb 4Qf+iVuZequf2WYOwrLv89PaydH4Ej1E8WLSYHs64Ooi7RRHErLtZliqT9LmYguJl+ VlIK+w2HE8hdA== From: Sasha Levin To: stable@vger.kernel.org Cc: Eric Farman , Cornelia Huck , Matthew Rosato , Christian Borntraeger , Sasha Levin Subject: [PATCH 5.15.y 1/4] s390/vfio_ccw: Ensure index for read/write regions are within range Date: Mon, 24 Aug 2026 10:05:52 -0400 Message-ID: <20260824140555.3097579-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026082011-underarm-plywood-1b0f@gregkh> References: <2026082011-underarm-plywood-1b0f@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Eric Farman [ Upstream commit 9f5f9a78fedc45bc29d6a0a64e3a3472361afae5 ] The introduction of the capability chain rightly clamped the region indexes to the range of the capabilities itself, but neglected to do so for the existing read/write regions which should also be enforced. Fixes: db8e5d17ac03 ("vfio-ccw: add capabilities chain") Cc: stable@vger.kernel.org Cc: Cornelia Huck Reviewed-by: Matthew Rosato Signed-off-by: Eric Farman Signed-off-by: Christian Borntraeger Stable-dep-of: 16b0798024c0 ("s390/vfio_ccw: Implement a crw lock") Signed-off-by: Sasha Levin --- drivers/s390/cio/vfio_ccw_async.c | 16 ++++++++++++++++ drivers/s390/cio/vfio_ccw_chp.c | 15 +++++++++++++++ drivers/s390/cio/vfio_ccw_ops.c | 7 +++---- 3 files changed, 34 insertions(+), 4 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_async.c b/drivers/s390/cio/vfio_ccw_async.c index 7a838e3d7c0fa..01f8cedc46e2a 100644 --- a/drivers/s390/cio/vfio_ccw_async.c +++ b/drivers/s390/cio/vfio_ccw_async.c @@ -8,6 +8,7 @@ */ #include +#include #include #include "vfio_ccw_private.h" @@ -25,11 +26,20 @@ static ssize_t vfio_ccw_async_region_read(struct vfio_ccw_private *private, return -EINVAL; mutex_lock(&private->io_mutex); + + if (i >= private->num_regions) { + ret = -EINVAL; + goto out_unlock; + } + + i = array_index_nospec(i, private->num_regions); region = private->region[i].data; if (copy_to_user(buf, (void *)region + pos, count)) ret = -EFAULT; else ret = count; + +out_unlock: mutex_unlock(&private->io_mutex); return ret; } @@ -49,6 +59,12 @@ static ssize_t vfio_ccw_async_region_write(struct vfio_ccw_private *private, if (!mutex_trylock(&private->io_mutex)) return -EAGAIN; + if (i >= private->num_regions) { + ret = -EINVAL; + goto out_unlock; + } + + i = array_index_nospec(i, private->num_regions); region = private->region[i].data; if (copy_from_user((void *)region + pos, buf, count)) { ret = -EFAULT; diff --git a/drivers/s390/cio/vfio_ccw_chp.c b/drivers/s390/cio/vfio_ccw_chp.c index 13b26a1c79886..11264e2adffcb 100644 --- a/drivers/s390/cio/vfio_ccw_chp.c +++ b/drivers/s390/cio/vfio_ccw_chp.c @@ -9,6 +9,7 @@ */ #include +#include #include #include "vfio_ccw_private.h" @@ -25,6 +26,13 @@ static ssize_t vfio_ccw_schib_region_read(struct vfio_ccw_private *private, return -EINVAL; mutex_lock(&private->io_mutex); + + if (i >= private->num_regions) { + ret = -EINVAL; + goto out; + } + + i = array_index_nospec(i, private->num_regions); region = private->region[i].data; if (cio_update_schib(private->sch)) { @@ -96,6 +104,12 @@ static ssize_t vfio_ccw_crw_region_read(struct vfio_ccw_private *private, list_del(&crw->next); mutex_lock(&private->io_mutex); + if (i >= private->num_regions) { + ret = -EINVAL; + goto out; + } + + i = array_index_nospec(i, private->num_regions); region = private->region[i].data; if (crw) @@ -108,6 +122,7 @@ static ssize_t vfio_ccw_crw_region_read(struct vfio_ccw_private *private, region->crw = 0; +out: mutex_unlock(&private->io_mutex); kfree(crw); diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index 7f540ad0b568b..b76b0521b456b 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -251,6 +251,7 @@ static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev, return vfio_ccw_mdev_read_io_region(private, buf, count, ppos); default: index -= VFIO_CCW_NUM_REGIONS; + index = array_index_nospec(index, private->num_regions); return private->region[index].ops->read(private, buf, count, ppos); } @@ -304,6 +305,7 @@ static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev, return vfio_ccw_mdev_write_io_region(private, buf, count, ppos); default: index -= VFIO_CCW_NUM_REGIONS; + index = array_index_nospec(index, private->num_regions); return private->region[index].ops->write(private, buf, count, ppos); } @@ -351,11 +353,8 @@ static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info, VFIO_CCW_NUM_REGIONS + private->num_regions) return -EINVAL; - info->index = array_index_nospec(info->index, - VFIO_CCW_NUM_REGIONS + - private->num_regions); - i = info->index - VFIO_CCW_NUM_REGIONS; + i = array_index_nospec(i, private->num_regions); info->offset = VFIO_CCW_INDEX_TO_OFFSET(info->index); info->size = private->region[i].size; -- 2.53.0