qubes-linux-kernel/0011-xen-blkfront-make-local-copy-of-response-before-usin.patch
Frédéric Pierret (fepitre) 22b6866243
Update to version 5.4.1
2019-12-01 02:00:43 +01:00

129 lines
4.7 KiB
Diff

From def16082c5e64f97d5d138ae638a6cde7a136432 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
<marmarek@invisiblethingslab.com>
Date: Wed, 16 Dec 2015 05:51:10 +0100
Subject: [PATCH] xen-blkfront: make local copy of response before using it
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Data on the shared page can be changed at any time by the backend. Make
a local copy, which is no longer controlled by the backend. And only
then access it.
This is part of XSA155.
CC: stable@vger.kernel.org
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
drivers/block/xen-blkfront.c | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index db7d28ac9747..3f6dbaf0265b 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1551,7 +1551,7 @@ static bool blkif_completion(unsigned long *id,
static irqreturn_t blkif_interrupt(int irq, void *dev_id)
{
struct request *req;
- struct blkif_response *bret;
+ struct blkif_response bret;
RING_IDX i, rp;
unsigned long flags;
struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)dev_id;
@@ -1568,8 +1568,8 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
for (i = rinfo->ring.rsp_cons; i != rp; i++) {
unsigned long id;
- bret = RING_GET_RESPONSE(&rinfo->ring, i);
- id = bret->id;
+ RING_COPY_RESPONSE(&rinfo->ring, i, &bret);
+ id = bret.id;
/*
* The backend has messed up and given us an id that we would
* never have given to it (we stamp it up to BLK_RING_SIZE -
@@ -1577,39 +1577,39 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
*/
if (id >= BLK_RING_SIZE(info)) {
WARN(1, "%s: response to %s has incorrect id (%ld)\n",
- info->gd->disk_name, op_name(bret->operation), id);
+ info->gd->disk_name, op_name(bret.operation), id);
/* We can't safely get the 'struct request' as
* the id is busted. */
continue;
}
req = rinfo->shadow[id].request;
- if (bret->operation != BLKIF_OP_DISCARD) {
+ if (bret.operation != BLKIF_OP_DISCARD) {
/*
* We may need to wait for an extra response if the
* I/O request is split in 2
*/
- if (!blkif_completion(&id, rinfo, bret))
+ if (!blkif_completion(&id, rinfo, &bret))
continue;
}
if (add_id_to_freelist(rinfo, id)) {
WARN(1, "%s: response to %s (id %ld) couldn't be recycled!\n",
- info->gd->disk_name, op_name(bret->operation), id);
+ info->gd->disk_name, op_name(bret.operation), id);
continue;
}
- if (bret->status == BLKIF_RSP_OKAY)
+ if (bret.status == BLKIF_RSP_OKAY)
blkif_req(req)->error = BLK_STS_OK;
else
blkif_req(req)->error = BLK_STS_IOERR;
- switch (bret->operation) {
+ switch (bret.operation) {
case BLKIF_OP_DISCARD:
- if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
+ if (unlikely(bret.status == BLKIF_RSP_EOPNOTSUPP)) {
struct request_queue *rq = info->rq;
printk(KERN_WARNING "blkfront: %s: %s op failed\n",
- info->gd->disk_name, op_name(bret->operation));
+ info->gd->disk_name, op_name(bret.operation));
blkif_req(req)->error = BLK_STS_NOTSUPP;
info->feature_discard = 0;
info->feature_secdiscard = 0;
@@ -1619,15 +1619,15 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
break;
case BLKIF_OP_FLUSH_DISKCACHE:
case BLKIF_OP_WRITE_BARRIER:
- if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
+ if (unlikely(bret.status == BLKIF_RSP_EOPNOTSUPP)) {
printk(KERN_WARNING "blkfront: %s: %s op failed\n",
- info->gd->disk_name, op_name(bret->operation));
+ info->gd->disk_name, op_name(bret.operation));
blkif_req(req)->error = BLK_STS_NOTSUPP;
}
- if (unlikely(bret->status == BLKIF_RSP_ERROR &&
+ if (unlikely(bret.status == BLKIF_RSP_ERROR &&
rinfo->shadow[id].req.u.rw.nr_segments == 0)) {
printk(KERN_WARNING "blkfront: %s: empty %s op failed\n",
- info->gd->disk_name, op_name(bret->operation));
+ info->gd->disk_name, op_name(bret.operation));
blkif_req(req)->error = BLK_STS_NOTSUPP;
}
if (unlikely(blkif_req(req)->error)) {
@@ -1640,9 +1640,9 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
/* fall through */
case BLKIF_OP_READ:
case BLKIF_OP_WRITE:
- if (unlikely(bret->status != BLKIF_RSP_OKAY))
+ if (unlikely(bret.status != BLKIF_RSP_OKAY))
dev_dbg(&info->xbdev->dev, "Bad return from blkdev data "
- "request: %x\n", bret->status);
+ "request: %x\n", bret.status);
break;
default:
--
2.21.0