On 29-Apr-19 2:53 PM, Ferruh Yigit wrote:
On 4/25/2019 6:17 PM, Herakliusz Lipiec wrote:
When secondary to primary process synchronization occours
there is no check for number of fds which could cause buffer overrun.
Bugzilla ID: 252
Fixes: c9aa56edec8e ("net/tap: access primary process queues from secondary")
Cc: rasl...@mellanox.com
Cc: sta...@dpdk.org
Signed-off-by: Herakliusz Lipiec <herakliusz.lip...@intel.com>
---
drivers/net/tap/rte_eth_tap.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index e9fda8cf6..4a2ef5ce7 100644
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -2111,6 +2111,10 @@ tap_mp_attach_queues(const char *port_name, struct
rte_eth_dev *dev)
TAP_LOG(DEBUG, "Received IPC reply for %s", reply_param->port_name);
/* Attach the queues from received file descriptors */
+ if (reply_param->rxq_count + reply_param->txq_count != reply->num_fds) {
+ TAP_LOG(ERR, "Unexpected number of fds received");
+ return -1;
+ }
Is there a way this can happen? If not I suggest remove the check.
Normally no, but theoretically this can trigger a buffer overrun if not
checked. After all, something could either fail on the other side, or
someone could send a fake message :) This data is coming from an
external source, so we need to sanity-check it.
dev->data->nb_rx_queues = reply_param->rxq_count;
dev->data->nb_tx_queues = reply_param->txq_count;
fd_iterator = 0;
@@ -2151,12 +2155,16 @@ tap_mp_sync_queues(const struct rte_mp_msg *request,
const void *peer)
/* Fill file descriptors for all queues */
reply.num_fds = 0;
reply_param->rxq_count = 0;
+ if (dev->data->nb_rx_queues + dev->data->nb_tx_queues >
+ RTE_MP_MAX_FD_NUM){
+ TAP_LOG(ERR, "Number of rx/tx queues exceeds max number of
fds");
+ return -1;
+ }
+1 for the check.
But what it does when return "-1", not send a message at all? If so would it be
better to send and error message back instead of waiting the receiver to
timeout?
There will be a different patch fixing this specific issue. Probably
this patch would need to be rebased on top of that.
for (queue = 0; queue < dev->data->nb_rx_queues; queue++) {
reply.fds[reply.num_fds++] = process_private->rxq_fds[queue];
reply_param->rxq_count++;
}
RTE_ASSERT(reply_param->rxq_count == dev->data->nb_rx_queues);
- RTE_ASSERT(reply_param->txq_count == dev->data->nb_tx_queues);
RTE_ASSERT(reply.num_fds <= RTE_MP_MAX_FD_NUM);
Since there is dynamic check above for "RTE_MP_MAX_FD_NUM", we can remove this
assert I think.
reply_param->txq_count = 0;
@@ -2164,7 +2172,8 @@ tap_mp_sync_queues(const struct rte_mp_msg *request,
const void *peer)
reply.fds[reply.num_fds++] = process_private->txq_fds[queue];
reply_param->txq_count++;
}
-
+ RTE_ASSERT(reply_param->txq_count == dev->data->nb_tx_queues);
+ RTE_ASSERT(reply.num_fds <= RTE_MP_MAX_FD_NUM);
Same for this assert, we can remove it.
And as syntax, please keep the empty line before next block.
/* Send reply */
strlcpy(reply.name, request->name, sizeof(reply.name));
strlcpy(reply_param->port_name, request_param->port_name,
--
Thanks,
Anatoly
