fds[] is leaked when qio_channel_readv_full() fails.
Use vmsg->fds[] instead of keeping a local fds[] array. Then we can
reuse goto fail to clean up fds. vmsg->fd_num must be zeroed before the
loop to make this safe.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
Message-id: 20200924151549.913737-8-stefa...@redhat.com
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
util/vhost-user-server.c | 50 ++++++++++++++++++----------------------
1 file changed, 23 insertions(+), 27 deletions(-)
diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
index 892815827d..5a60e2ca2a 100644
--- a/util/vhost-user-server.c
+++ b/util/vhost-user-server.c
@@ -100,21 +100,11 @@ vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg
*vmsg)
};
int rc, read_bytes = 0;
Error *local_err = NULL;
- /*
- * Store fds/nfds returned from qio_channel_readv_full into
- * temporary variables.
- *
- * VhostUserMsg is a packed structure, gcc will complain about passing
- * pointer to a packed structure member if we pass &VhostUserMsg.fd_num
- * and &VhostUserMsg.fds directly when calling qio_channel_readv_full,
- * thus two temporary variables nfds and fds are used here.
- */
- size_t nfds = 0, nfds_t = 0;
const size_t max_fds = G_N_ELEMENTS(vmsg->fds);
- int *fds_t = NULL;
VuServer *server = container_of(vu_dev, VuServer, vu_dev);
QIOChannel *ioc = server->ioc;
+ vmsg->fd_num = 0;
if (!ioc) {
error_report_err(local_err);
goto fail;
@@ -122,41 +112,47 @@ vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg
*vmsg)
assert(qemu_in_coroutine());
do {
+ size_t nfds = 0;
+ int *fds = NULL;
+
/*
* qio_channel_readv_full may have short reads, keeping calling it
* until getting VHOST_USER_HDR_SIZE or 0 bytes in total
*/
- rc = qio_channel_readv_full(ioc, &iov, 1, &fds_t, &nfds_t, &local_err);
+ rc = qio_channel_readv_full(ioc, &iov, 1, &fds, &nfds, &local_err);
if (rc < 0) {
if (rc == QIO_CHANNEL_ERR_BLOCK) {
+ assert(local_err == NULL);
qio_channel_yield(ioc, G_IO_IN);
continue;
} else {
error_report_err(local_err);
- return false;
+ goto fail;
}
}
- read_bytes += rc;
- if (nfds_t > 0) {
- if (nfds + nfds_t > max_fds) {
+
+ if (nfds > 0) {
+ if (vmsg->fd_num + nfds > max_fds) {
error_report("A maximum of %zu fds are allowed, "
"however got %lu fds now",
- max_fds, nfds + nfds_t);
+ max_fds, vmsg->fd_num + nfds);
+ g_free(fds);
goto fail;
}
- memcpy(vmsg->fds + nfds, fds_t,
- nfds_t *sizeof(vmsg->fds[0]));
- nfds += nfds_t;
- g_free(fds_t);
+ memcpy(vmsg->fds + vmsg->fd_num, fds, nfds * sizeof(vmsg->fds[0]));
+ vmsg->fd_num += nfds;
+ g_free(fds);
}
- if (read_bytes == VHOST_USER_HDR_SIZE || rc == 0) {
- break;
+
+ if (rc == 0) { /* socket closed */
+ goto fail;
}
- iov.iov_base = (char *)vmsg + read_bytes;
- iov.iov_len = VHOST_USER_HDR_SIZE - read_bytes;
- } while (true);
- vmsg->fd_num = nfds;
+ iov.iov_base += rc;
+ iov.iov_len -= rc;
+ read_bytes += rc;
+ } while (read_bytes != VHOST_USER_HDR_SIZE);
+
/* qio_channel_readv_full will make socket fds blocking, unblock them */
vmsg_unblock_fds(vmsg);
if (vmsg->size > sizeof(vmsg->payload)) {
--
2.26.2
