diff mbox series

mt76: fix monitor mode crash with sdio driver

Message ID d065e4492a9e995d6ebe95c7ad8a1ec6183f56ef.1646277169.git.deren.wu@mediatek.com (mailing list archive)
State Superseded
Delegated to: Felix Fietkau
Headers show
Series mt76: fix monitor mode crash with sdio driver | expand

Commit Message

Deren Wu March 3, 2022, 3:28 a.m. UTC
From: Deren Wu <deren.wu@mediatek.com>

mt7921s driver may receive frames with fragment buffers. If there is a
CTS packet received in monitor mode, the payload is 10 bytes only and
need 6 bytes header padding after RXD buffer. However, only RXD in the
first linear buffer, if we pull buffer size RXD-size+6 bytes with
skb_pull(), that would trigger "BUG_ON(skb->len < skb->data_len)" in
__skb_pull().

To avoid the nonlinear buffer issue, enlarge the RXD size from 128 to
136 to make sure all MCU operation in linear buffer.

136 = 128 + 8
  128 : RXD size
  8   : max header padding length

[   52.007562] kernel BUG at include/linux/skbuff.h:2313!
[   52.007578] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[   52.007987] pc : skb_pull+0x48/0x4c
[   52.008015] lr : mt7921_queue_rx_skb+0x494/0x890 [mt7921_common]
[   52.008361] Call trace:
[   52.008377]  skb_pull+0x48/0x4c
[   52.008400]  mt76s_net_worker+0x134/0x1b0 [mt76_sdio 35339a92c6eb7d4bbcc806a1d22f56365565135c]
[   52.008431]  __mt76_worker_fn+0xe8/0x170 [mt76 ef716597d11a77150bc07e3fdd68eeb0f9b56917]
[   52.008449]  kthread+0x148/0x3ac
[   52.008466]  ret_from_fork+0x10/0x30

Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
---
 drivers/net/wireless/mediatek/mt76/mt76.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Deren Wu March 3, 2022, 9:12 a.m. UTC | #1
Hi Felix,

I need to submit v2 patch. Please drop this one.


Thanks,
Deren


On Thu, 2022-03-03 at 11:28 +0800, Deren Wu wrote:
> From: Deren Wu <deren.wu@mediatek.com>
> 
> mt7921s driver may receive frames with fragment buffers. If there is
> a
> CTS packet received in monitor mode, the payload is 10 bytes only and
> need 6 bytes header padding after RXD buffer. However, only RXD in
> the
> first linear buffer, if we pull buffer size RXD-size+6 bytes with
> skb_pull(), that would trigger "BUG_ON(skb->len < skb->data_len)" in
> __skb_pull().
> 
> To avoid the nonlinear buffer issue, enlarge the RXD size from 128 to
> 136 to make sure all MCU operation in linear buffer.
> 
> 136 = 128 + 8
>   128 : RXD size
>   8   : max header padding length
> 
> [   52.007562] kernel BUG at include/linux/skbuff.h:2313!
> [   52.007578] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> [   52.007987] pc : skb_pull+0x48/0x4c
> [   52.008015] lr : mt7921_queue_rx_skb+0x494/0x890 [mt7921_common]
> [   52.008361] Call trace:
> [   52.008377]  skb_pull+0x48/0x4c
> [   52.008400]  mt76s_net_worker+0x134/0x1b0 [mt76_sdio
> 35339a92c6eb7d4bbcc806a1d22f56365565135c]
> [   52.008431]  __mt76_worker_fn+0xe8/0x170 [mt76
> ef716597d11a77150bc07e3fdd68eeb0f9b56917]
> [   52.008449]  kthread+0x148/0x3ac
> [   52.008466]  ret_from_fork+0x10/0x30
> 
> Co-developed-by: Sean Wang <sean.wang@mediatek.com>
> Signed-off-by: Sean Wang <sean.wang@mediatek.com>
> Signed-off-by: Deren Wu <deren.wu@mediatek.com>
> ---
>  drivers/net/wireless/mediatek/mt76/mt76.h | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h
> b/drivers/net/wireless/mediatek/mt76/mt76.h
> index 5e10fe156926..4f4ce3b3df54 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt76.h
> +++ b/drivers/net/wireless/mediatek/mt76/mt76.h
> @@ -19,7 +19,8 @@
>  
>  #define MT_MCU_RING_SIZE	32
>  #define MT_RX_BUF_SIZE		2048
> -#define MT_SKB_HEAD_LEN		128
> +/* 136 = 128+8. 128: RXD, 8:max header padding*/
> +#define MT_SKB_HEAD_LEN		136
>  
>  #define MT_MAX_NON_AQL_PKT	16
>  #define MT_TXQ_FREE_THR		32
diff mbox series

Patch

diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index 5e10fe156926..4f4ce3b3df54 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -19,7 +19,8 @@ 
 
 #define MT_MCU_RING_SIZE	32
 #define MT_RX_BUF_SIZE		2048
-#define MT_SKB_HEAD_LEN		128
+/* 136 = 128+8. 128: RXD, 8:max header padding*/
+#define MT_SKB_HEAD_LEN		136
 
 #define MT_MAX_NON_AQL_PKT	16
 #define MT_TXQ_FREE_THR		32