[PATCH net] ionic: linearize tso skb with too many frags
From: Shannon Nelson <hidden>
Date: 2021-03-16 18:53:54
Subsystem:
networking drivers, pensando ethernet drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Brett Creeley, Linus Torvalds
We were linearizing non-TSO skbs that had too many frags, but
we weren't checking number of frags on TSO skbs. This could
lead to a bad page reference when we received a TSO skb with
more frags than the Tx descriptor could support.
Fixes: 0f3154e6bcb3 ("ionic: Add Tx and Rx handling")
Signed-off-by: Shannon Nelson <redacted>
---
.../net/ethernet/pensando/ionic/ionic_txrx.c | 28 ++++++++++---------
1 file changed, 15 insertions(+), 13 deletions(-)
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
index 162a1ff1e9d2..462b0d106be4 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c@@ -1079,25 +1079,27 @@ static int ionic_tx_descs_needed(struct ionic_queue *q, struct sk_buff *skb) { int sg_elems = q->lif->qtype_info[IONIC_QTYPE_TXQ].max_sg_elems; struct ionic_tx_stats *stats = q_to_tx_stats(q); + int ndescs; int err; - /* If TSO, need roundup(skb->len/mss) descs */ + /* If TSO, need roundup(skb->len/mss) descs + * If non-TSO, just need 1 desc and nr_frags sg elems + */ if (skb_is_gso(skb)) - return (skb->len / skb_shinfo(skb)->gso_size) + 1; + ndescs = (skb->len / skb_shinfo(skb)->gso_size) + 1; + else + ndescs = 1; - /* If non-TSO, just need 1 desc and nr_frags sg elems */ - if (skb_shinfo(skb)->nr_frags <= sg_elems) - return 1; + /* If too many frags, linearize */ + if (skb_shinfo(skb)->nr_frags > sg_elems) { + err = skb_linearize(skb); + if (err) + return err; - /* Too many frags, so linearize */ - err = skb_linearize(skb); - if (err) - return err; - - stats->linearize++; + stats->linearize++; + } - /* Need 1 desc and zero sg elems */ - return 1; + return ndescs; } static int ionic_maybe_stop_tx(struct ionic_queue *q, int ndescs)
--
2.17.1