From: Íñigo Huguet ihuguet@redhat.com
[ Upstream commit 0a242eb2913a4aa3d6fbdb86559f27628e9466f3 ]
Trying to get the channel from the tx_queue variable here is wrong because we can only be here if tx_queue is NULL, so we shouldn't dereference it. As the above comment in the code says, this is very unlikely to happen, but it's wrong anyway so let's fix it.
I hit this issue because of a different bug that caused tx_queue to be NULL. If that happens, this is the error message that we get here: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 [...] RIP: 0010:efx_hard_start_xmit+0x153/0x170 [sfc]
Fixes: 12804793b17c ("sfc: decouple TXQ type from label") Reported-by: Tianhao Zhao tizhao@redhat.com Signed-off-by: Íñigo Huguet ihuguet@redhat.com Acked-by: Edward Cree ecree.xilinx@gmail.com Link: https://lore.kernel.org/r/20220914111135.21038-1-ihuguet@redhat.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/sfc/tx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c index 6983799e1c05..e0bc2c1dc81a 100644 --- a/drivers/net/ethernet/sfc/tx.c +++ b/drivers/net/ethernet/sfc/tx.c @@ -548,7 +548,7 @@ netdev_tx_t efx_hard_start_xmit(struct sk_buff *skb, * previous packets out. */ if (!netdev_xmit_more()) - efx_tx_send_pending(tx_queue->channel); + efx_tx_send_pending(efx_get_tx_channel(efx, index)); return NETDEV_TX_OK; }