rte_pktmbuf_alloc_bulk is called by the zero-copy receiver to allocate new mbufs to be provided to the sender. The allocated mbuf pointers are stored in a ring, but the alloc function doesn't implement index wrap-around, so it writes past the end of the array. This results in memory corruption and duplicate mbufs being received.
Allocate 2x the space for the mbuf ring, so that the alloc function
has a contiguous array to write to, then copy the excess entries
to the start of the array.
Fixes: 43b815d88188 ("net/memif: support zero-copy slave")
Cc: sta...@dpdk.org
Signed-off-by: Mihai Brodschi <mihai.brods...@broadcom.com>
---
v2:
- fix email formatting
---
drivers/net/memif/rte_eth_memif.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/net/memif/rte_eth_memif.c
b/drivers/net/memif/rte_eth_memif.c
index 16da22b5c6..3491c53cf1 100644
--- a/drivers/net/memif/rte_eth_memif.c
+++ b/drivers/net/memif/rte_eth_memif.c
@@ -600,6 +600,10 @@ eth_memif_rx_zc(void *queue, struct rte_mbuf **bufs,
uint16_t nb_pkts)
ret = rte_pktmbuf_alloc_bulk(mq->mempool, &mq->buffers[head & mask],
n_slots);
if (unlikely(ret < 0))
goto no_free_mbufs;
+ if (unlikely(n_slots > ring_size - (head & mask))) {
+ rte_memcpy(mq->buffers, &mq->buffers[ring_size],
+ (n_slots + (head & mask) - ring_size) * sizeof(struct
rte_mbuf *));
+ }
while (n_slots--) {
s0 = head++ & mask;
@@ -1245,8 +1249,12 @@ memif_init_queues(struct rte_eth_dev *dev)
}
mq->buffers = NULL;
if (pmd->flags & ETH_MEMIF_FLAG_ZERO_COPY) {
+ /*
+ * Allocate 2x ring_size to reserve a contiguous array
for
+ * rte_pktmbuf_alloc_bulk (to store allocated mbufs).
+ */
mq->buffers = rte_zmalloc("bufs", sizeof(struct
rte_mbuf *) *
- (1 << mq->log2_ring_size), 0);
+ (1 << (mq->log2_ring_size +
1)), 0);
if (mq->buffers == NULL)
return -ENOMEM;
}
--
2.43.0
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