From: Jakub Kicinski kuba@kernel.org
[ Upstream commit c31f26c8f69f776759cbbdfb38e40ea91aa0dd65 ]
When reading the timestamp is required bnxt_tx_int() hands over the ownership of the completed skb to the PTP worker. The skb should not be used afterwards, as the worker may run before the rest of our code and free the skb, leading to a use-after-free.
Since dev_kfree_skb_any() accepts NULL make the loss of ownership more obvious and set skb to NULL.
Fixes: 83bb623c968e ("bnxt_en: Transmit and retrieve packet timestamps") Reviewed-by: Andy Gospodarek gospo@broadcom.com Reviewed-by: Michael Chan michael.chan@broadcom.com Link: https://lore.kernel.org/r/20220921201005.335390-1-kuba@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 6962abe2358b..a6ca7ba5276c 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -709,7 +709,6 @@ static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
for (i = 0; i < nr_pkts; i++) { struct bnxt_sw_tx_bd *tx_buf; - bool compl_deferred = false; struct sk_buff *skb; int j, last;
@@ -718,6 +717,8 @@ static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts) skb = tx_buf->skb; tx_buf->skb = NULL;
+ tx_bytes += skb->len; + if (tx_buf->is_push) { tx_buf->is_push = 0; goto next_tx_int; @@ -738,8 +739,9 @@ static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts) } if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) { if (bp->flags & BNXT_FLAG_CHIP_P5) { + /* PTP worker takes ownership of the skb */ if (!bnxt_get_tx_ts_p5(bp, skb)) - compl_deferred = true; + skb = NULL; else atomic_inc(&bp->ptp_cfg->tx_avail); } @@ -748,9 +750,7 @@ static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts) next_tx_int: cons = NEXT_TX(cons);
- tx_bytes += skb->len; - if (!compl_deferred) - dev_kfree_skb_any(skb); + dev_kfree_skb_any(skb); }
netdev_tx_completed_queue(txq, nr_pkts, tx_bytes);