6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Wei Fang <wei.fang@xxxxxxx>
commit 39ab773e4c120f7f98d759415ccc2aca706bbc10 upstream.
When a DMA mapping error occurs while processing skb frags, it will free
one more tx_swbd than expected, so fix this off-by-one issue.
Fixes: d4fd0404c1c9 ("enetc: Introduce basic PF and VF ENETC ethernet drivers")
Cc: stable@xxxxxxxxxxxxxxx
Suggested-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Suggested-by: Michal Swiatkowski <michal.swiatkowski@xxxxxxxxxxxxxxx>
Signed-off-by: Wei Fang <wei.fang@xxxxxxx>
Reviewed-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Reviewed-by: Claudiu Manoil <claudiu.manoil@xxxxxxx>
Link: https://patch.msgid.link/20250224111251.1061098-2-wei.fang@xxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/freescale/enetc/enetc.c | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -145,6 +145,24 @@ static int enetc_ptp_parse(struct sk_buf
return 0;
}
+/**
+ * enetc_unwind_tx_frame() - Unwind the DMA mappings of a multi-buffer Tx frame
+ * @tx_ring: Pointer to the Tx ring on which the buffer descriptors are located
+ * @count: Number of Tx buffer descriptors which need to be unmapped
+ * @i: Index of the last successfully mapped Tx buffer descriptor
+ */
+static void enetc_unwind_tx_frame(struct enetc_bdr *tx_ring, int count, int i)
+{
+ while (count--) {
+ struct enetc_tx_swbd *tx_swbd = &tx_ring->tx_swbd[i];
+
+ enetc_free_tx_frame(tx_ring, tx_swbd);
+ if (i == 0)
+ i = tx_ring->bd_count;
+ i--;
+ }
+}
+
static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
{
bool do_vlan, do_onestep_tstamp = false, do_twostep_tstamp = false;
@@ -328,13 +346,7 @@ static int enetc_map_tx_buffs(struct ene
dma_err:
dev_err(tx_ring->dev, "DMA map error");
- do {
- tx_swbd = &tx_ring->tx_swbd[i];
- enetc_free_tx_frame(tx_ring, tx_swbd);
- if (i == 0)
- i = tx_ring->bd_count;
- i--;
- } while (count--);
+ enetc_unwind_tx_frame(tx_ring, count, i);
return 0;
}
