From: Shannon Nelson <snelson@pensando.io>
Date: Tue, 16 Mar 2021 17:07:47 -0700
Subject: ionic: linearize tso skb with too many frags
Patch-mainline: v5.12-rc5
Git-commit: d2c21422323b06938b3c070361dc544f047489d7
References: bsc#1167773
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.
v2: use gso_segs rather than yet another division
don't rework the check on the nr_frags
Fixes: 0f3154e6bcb3 ("ionic: Add Tx and Rx handling")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
--- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
@@ -987,15 +987,17 @@ static int ionic_tx(struct ionic_queue *
static int ionic_tx_descs_needed(struct ionic_queue *q, struct sk_buff *skb)
{
struct ionic_tx_stats *stats = q_to_tx_stats(q);
+ int ndescs;
int err;
- /* If TSO, need roundup(skb->len/mss) descs */
+ /* Each desc is mss long max, so a descriptor for each gso_seg */
if (skb_is_gso(skb))
- return (skb->len / skb_shinfo(skb)->gso_size) + 1;
+ ndescs = skb_shinfo(skb)->gso_segs;
+ else
+ ndescs = 1;
- /* If non-TSO, just need 1 desc and nr_frags sg elems */
if (skb_shinfo(skb)->nr_frags <= IONIC_TX_MAX_SG_ELEMS)
- return 1;
+ return ndescs;
/* Too many frags, so linearize */
err = skb_linearize(skb);
@@ -1004,8 +1006,7 @@ static int ionic_tx_descs_needed(struct
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)