6.9-stable review patch. If anyone has any objections, please let me know.
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From: Ken Milmore ken.milmore@gmail.com
commit c71e3a5cffd5309d7f84444df03d5b72600cc417 upstream.
An issue was found on the RTL8125b when transmitting small fragmented packets, whereby invalid entries were inserted into the transmit ring buffer, subsequently leading to calls to dma_unmap_single() with a null address.
This was caused by rtl8169_start_xmit() not noticing changes to nr_frags which may occur when small packets are padded (to work around hardware quirks) in rtl8169_tso_csum_v2().
To fix this, postpone inspecting nr_frags until after any padding has been applied.
Fixes: 9020845fb5d6 ("r8169: improve rtl8169_start_xmit") Cc: stable@vger.kernel.org Signed-off-by: Ken Milmore ken.milmore@gmail.com Reviewed-by: Heiner Kallweit hkallweit1@gmail.com Link: https://lore.kernel.org/r/27ead18b-c23d-4f49-a020-1fc482c5ac95@gmail.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/realtek/r8169_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -4335,11 +4335,11 @@ static void rtl8169_doorbell(struct rtl8 static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb, struct net_device *dev) { - unsigned int frags = skb_shinfo(skb)->nr_frags; struct rtl8169_private *tp = netdev_priv(dev); unsigned int entry = tp->cur_tx % NUM_TX_DESC; struct TxDesc *txd_first, *txd_last; bool stop_queue, door_bell; + unsigned int frags; u32 opts[2];
if (unlikely(!rtl_tx_slots_avail(tp))) { @@ -4362,6 +4362,7 @@ static netdev_tx_t rtl8169_start_xmit(st
txd_first = tp->TxDescArray + entry;
+ frags = skb_shinfo(skb)->nr_frags; if (frags) { if (rtl8169_xmit_frags(tp, skb, opts, entry)) goto err_dma_1;