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[PATCH 1/2] libvhost-user: return early on virtqueue errors
From: |
Stefan Hajnoczi |
Subject: |
[PATCH 1/2] libvhost-user: return early on virtqueue errors |
Date: |
Mon, 21 Sep 2020 12:34:19 +0100 |
vu_panic() is not guaranteed to exit the program. Return early when
errors are encountered.
Note that libvhost-user does not have an "unmap" operation for mapped
descriptors. Therefore it is correct to return without explicit cleanup.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
contrib/libvhost-user/libvhost-user.c | 27 +++++++++++++++++----------
1 file changed, 17 insertions(+), 10 deletions(-)
diff --git a/contrib/libvhost-user/libvhost-user.c
b/contrib/libvhost-user/libvhost-user.c
index 53f16bdf08..27626e629a 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -2407,7 +2407,7 @@ vu_queue_set_notification(VuDev *dev, VuVirtq *vq, int
enable)
}
}
-static void
+static bool
virtqueue_map_desc(VuDev *dev,
unsigned int *p_num_sg, struct iovec *iov,
unsigned int max_num_sg, bool is_write,
@@ -2419,7 +2419,7 @@ virtqueue_map_desc(VuDev *dev,
if (!sz) {
vu_panic(dev, "virtio: zero sized buffers are not allowed");
- return;
+ return false;
}
while (sz) {
@@ -2427,13 +2427,13 @@ virtqueue_map_desc(VuDev *dev,
if (num_sg == max_num_sg) {
vu_panic(dev, "virtio: too many descriptors in indirect table");
- return;
+ return false;
}
iov[num_sg].iov_base = vu_gpa_to_va(dev, &len, pa);
if (iov[num_sg].iov_base == NULL) {
vu_panic(dev, "virtio: invalid address for buffers");
- return;
+ return false;
}
iov[num_sg].iov_len = len;
num_sg++;
@@ -2442,6 +2442,7 @@ virtqueue_map_desc(VuDev *dev,
}
*p_num_sg = num_sg;
+ return true;
}
static void *
@@ -2479,6 +2480,7 @@ vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int
idx, size_t sz)
if (desc[i].flags & VRING_DESC_F_INDIRECT) {
if (desc[i].len % sizeof(struct vring_desc)) {
vu_panic(dev, "Invalid size for indirect buffer table");
+ return NULL;
}
/* loop over the indirect descriptor table */
@@ -2506,22 +2508,27 @@ vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int
idx, size_t sz)
/* Collect all the descriptors */
do {
if (desc[i].flags & VRING_DESC_F_WRITE) {
- virtqueue_map_desc(dev, &in_num, iov + out_num,
- VIRTQUEUE_MAX_SIZE - out_num, true,
- desc[i].addr, desc[i].len);
+ if (!virtqueue_map_desc(dev, &in_num, iov + out_num,
+ VIRTQUEUE_MAX_SIZE - out_num, true,
+ desc[i].addr, desc[i].len)) {
+ return NULL;
+ }
} else {
if (in_num) {
vu_panic(dev, "Incorrect order for descriptors");
return NULL;
}
- virtqueue_map_desc(dev, &out_num, iov,
- VIRTQUEUE_MAX_SIZE, false,
- desc[i].addr, desc[i].len);
+ if (!virtqueue_map_desc(dev, &out_num, iov,
+ VIRTQUEUE_MAX_SIZE, false,
+ desc[i].addr, desc[i].len)) {
+ return NULL;
+ }
}
/* If we've got too many, that implies a descriptor loop. */
if ((in_num + out_num) > max) {
vu_panic(dev, "Looped descriptor");
+ return NULL;
}
rc = virtqueue_read_next_desc(dev, desc, i, max, &i);
} while (rc == VIRTQUEUE_READ_DESC_MORE);
--
2.26.2