6.6-stable review patch. If anyone has any objections, please let me know.
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From: Wei Fang wei.fang@nxp.com
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@vger.kernel.org Suggested-by: Vladimir Oltean vladimir.oltean@nxp.com Suggested-by: Michal Swiatkowski michal.swiatkowski@linux.intel.com Signed-off-by: Wei Fang wei.fang@nxp.com Reviewed-by: Vladimir Oltean vladimir.oltean@nxp.com Reviewed-by: Claudiu Manoil claudiu.manoil@nxp.com Link: https://patch.msgid.link/20250224111251.1061098-2-wei.fang@nxp.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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; }