* [PATCH net] sfc: fix null pointer dereference in efx_hard_start_xmit
@ 2022-09-14 11:11 Íñigo Huguet
2022-09-14 17:50 ` Edward Cree
2022-09-20 1:20 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Íñigo Huguet @ 2022-09-14 11:11 UTC (permalink / raw)
To: ecree.xilinx, habetsm.xilinx
Cc: davem, edumazet, kuba, pabeni, netdev, Íñigo Huguet,
Tianhao Zhao
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>
---
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 d12474042c84..c5f88f7a7a04 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -549,7 +549,7 @@ 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;
}
--
2.34.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net] sfc: fix null pointer dereference in efx_hard_start_xmit
2022-09-14 11:11 [PATCH net] sfc: fix null pointer dereference in efx_hard_start_xmit Íñigo Huguet
@ 2022-09-14 17:50 ` Edward Cree
2022-09-20 1:20 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: Edward Cree @ 2022-09-14 17:50 UTC (permalink / raw)
To: Íñigo Huguet, habetsm.xilinx
Cc: davem, edumazet, kuba, pabeni, netdev, Tianhao Zhao
On 14/09/2022 12:11, Íñigo Huguet wrote:
> 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>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net] sfc: fix null pointer dereference in efx_hard_start_xmit
2022-09-14 11:11 [PATCH net] sfc: fix null pointer dereference in efx_hard_start_xmit Íñigo Huguet
2022-09-14 17:50 ` Edward Cree
@ 2022-09-20 1:20 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-09-20 1:20 UTC (permalink / raw)
To: =?utf-8?b?w43DsWlnbyBIdWd1ZXQgPGlodWd1ZXRAcmVkaGF0LmNvbT4=?=
Cc: ecree.xilinx, habetsm.xilinx, davem, edumazet, kuba, pabeni,
netdev, tizhao
Hello:
This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:
On Wed, 14 Sep 2022 13:11:35 +0200 you wrote:
> 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]
>
> [...]
Here is the summary with links:
- [net] sfc: fix null pointer dereference in efx_hard_start_xmit
https://git.kernel.org/netdev/net/c/0a242eb2913a
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 3+ messages in thread
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