2022-05-18 07:12:35

by Hangyu Hua

Subject: [PATCH] drm: bridge: sii8620: fix possible off-by-one

The next call to sii8620_burst_get_tx_buf will result in off-by-one
When ctx->burst.tx_count + size == ARRAY_SIZE(ctx->burst.tx_buf). The same
thing happens in sii8620_burst_get_rx_buf.

This patch also change tx_count and tx_buf to rx_count and rx_buf in
sii8620_burst_get_rx_buf. It is unreasonable to check tx_buf's size and
use rx_buf.

Fixes: e19e9c692f81 ("drm/bridge/sii8620: add support for burst eMSC transmissions")
Signed-off-by: Hangyu Hua <[email protected]>
---
drivers/gpu/drm/bridge/sil-sii8620.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c
index ec7745c31da0..ab0bce4a988c 100644
--- a/drivers/gpu/drm/bridge/sil-sii8620.c
+++ b/drivers/gpu/drm/bridge/sil-sii8620.c
@@ -605,7 +605,7 @@ static void *sii8620_burst_get_tx_buf(struct sii8620 *ctx, int len)
u8 *buf = &ctx->burst.tx_buf[ctx->burst.tx_count];
int size = len + 2;

- if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
+ if (ctx->burst.tx_count + size >= ARRAY_SIZE(ctx->burst.tx_buf)) {
dev_err(ctx->dev, "TX-BLK buffer exhausted\n");
ctx->error = -EINVAL;
return NULL;
@@ -622,7 +622,7 @@ static u8 *sii8620_burst_get_rx_buf(struct sii8620 *ctx, int len)
u8 *buf = &ctx->burst.rx_buf[ctx->burst.rx_count];
int size = len + 1;

- if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
+ if (ctx->burst.rx_count + size >= ARRAY_SIZE(ctx->burst.rx_buf)) {
dev_err(ctx->dev, "RX-BLK buffer exhausted\n");
ctx->error = -EINVAL;
return NULL;
--
2.25.1

2022-05-18 08:00:17

by Andrzej Hajda

Subject: Re: [PATCH] drm: bridge: sii8620: fix possible off-by-one

On 18.05.2022 08:58, Hangyu Hua wrote:
> The next call to sii8620_burst_get_tx_buf will result in off-by-one
> When ctx->burst.tx_count + size == ARRAY_SIZE(ctx->burst.tx_buf). The same
> thing happens in sii8620_burst_get_rx_buf.
>
> This patch also change tx_count and tx_buf to rx_count and rx_buf in
> sii8620_burst_get_rx_buf. It is unreasonable to check tx_buf's size and
> use rx_buf.
>
> Fixes: e19e9c692f81 ("drm/bridge/sii8620: add support for burst eMSC transmissions")
> Signed-off-by: Hangyu Hua <[email protected]>
Reviewed-by: Andrzej Hajda <[email protected]>

Regards
Andrzej
> ---
> drivers/gpu/drm/bridge/sil-sii8620.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c
> index ec7745c31da0..ab0bce4a988c 100644
> --- a/drivers/gpu/drm/bridge/sil-sii8620.c
> +++ b/drivers/gpu/drm/bridge/sil-sii8620.c
> @@ -605,7 +605,7 @@ static void *sii8620_burst_get_tx_buf(struct sii8620 *ctx, int len)
> u8 *buf = &ctx->burst.tx_buf[ctx->burst.tx_count];
> int size = len + 2;
>
> - if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
> + if (ctx->burst.tx_count + size >= ARRAY_SIZE(ctx->burst.tx_buf)) {
> dev_err(ctx->dev, "TX-BLK buffer exhausted\n");
> ctx->error = -EINVAL;
> return NULL;
> @@ -622,7 +622,7 @@ static u8 *sii8620_burst_get_rx_buf(struct sii8620 *ctx, int len)
> u8 *buf = &ctx->burst.rx_buf[ctx->burst.rx_count];
> int size = len + 1;
>
> - if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
> + if (ctx->burst.rx_count + size >= ARRAY_SIZE(ctx->burst.rx_buf)) {
> dev_err(ctx->dev, "RX-BLK buffer exhausted\n");
> ctx->error = -EINVAL;
> return NULL;

2022-06-23 04:43:01

by Hangyu Hua

Subject: Re: [PATCH] drm: bridge: sii8620: fix possible off-by-one

On 2022/5/18 15:57, Andrzej Hajda wrote:
>
>
> On 18.05.2022 08:58, Hangyu Hua wrote:
>> The next call to sii8620_burst_get_tx_buf will result in off-by-one
>> When ctx->burst.tx_count + size == ARRAY_SIZE(ctx->burst.tx_buf). The
>> same
>> thing happens in sii8620_burst_get_rx_buf.
>>
>> This patch also change tx_count and tx_buf to rx_count and rx_buf in
>> sii8620_burst_get_rx_buf. It is unreasonable to check tx_buf's size and
>> use rx_buf.
>>
>> Fixes: e19e9c692f81 ("drm/bridge/sii8620: add support for burst eMSC
>> transmissions")
>> Signed-off-by: Hangyu Hua <[email protected]>
> Reviewed-by: Andrzej Hajda <[email protected]>
>
> Regards
> Andrzej
>> ---
>>   drivers/gpu/drm/bridge/sil-sii8620.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c
>> b/drivers/gpu/drm/bridge/sil-sii8620.c
>> index ec7745c31da0..ab0bce4a988c 100644
>> --- a/drivers/gpu/drm/bridge/sil-sii8620.c
>> +++ b/drivers/gpu/drm/bridge/sil-sii8620.c
>> @@ -605,7 +605,7 @@ static void *sii8620_burst_get_tx_buf(struct
>> sii8620 *ctx, int len)
>>       u8 *buf = &ctx->burst.tx_buf[ctx->burst.tx_count];
>>       int size = len + 2;
>> -    if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
>> +    if (ctx->burst.tx_count + size >= ARRAY_SIZE(ctx->burst.tx_buf)) {
>>           dev_err(ctx->dev, "TX-BLK buffer exhausted\n");
>>           ctx->error = -EINVAL;
>>           return NULL;
>> @@ -622,7 +622,7 @@ static u8 *sii8620_burst_get_rx_buf(struct sii8620
>> *ctx, int len)
>>       u8 *buf = &ctx->burst.rx_buf[ctx->burst.rx_count];
>>       int size = len + 1;
>> -    if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
>> +    if (ctx->burst.rx_count + size >= ARRAY_SIZE(ctx->burst.rx_buf)) {
>>           dev_err(ctx->dev, "RX-BLK buffer exhausted\n");
>>           ctx->error = -EINVAL;
>>           return NULL;
>

Hi guys,

Another patches for this module that I submitted at the same time as
this one have been merged. Is this patch forgotten to merge?

Thanks,
Hangyu

2022-07-04 19:04:07

by Robert Foss

Subject: Re: [PATCH] drm: bridge: sii8620: fix possible off-by-one

On Thu, 23 Jun 2022 at 04:55, Hangyu Hua <[email protected]> wrote:
>
> On 2022/5/18 15:57, Andrzej Hajda wrote:
> >
> >
> > On 18.05.2022 08:58, Hangyu Hua wrote:
> >> The next call to sii8620_burst_get_tx_buf will result in off-by-one
> >> When ctx->burst.tx_count + size == ARRAY_SIZE(ctx->burst.tx_buf). The
> >> same
> >> thing happens in sii8620_burst_get_rx_buf.
> >>
> >> This patch also change tx_count and tx_buf to rx_count and rx_buf in
> >> sii8620_burst_get_rx_buf. It is unreasonable to check tx_buf's size and
> >> use rx_buf.
> >>
> >> Fixes: e19e9c692f81 ("drm/bridge/sii8620: add support for burst eMSC
> >> transmissions")
> >> Signed-off-by: Hangyu Hua <[email protected]>
> > Reviewed-by: Andrzej Hajda <[email protected]>
> >
> > Regards
> > Andrzej
> >> ---
> >> drivers/gpu/drm/bridge/sil-sii8620.c | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c
> >> b/drivers/gpu/drm/bridge/sil-sii8620.c
> >> index ec7745c31da0..ab0bce4a988c 100644
> >> --- a/drivers/gpu/drm/bridge/sil-sii8620.c
> >> +++ b/drivers/gpu/drm/bridge/sil-sii8620.c
> >> @@ -605,7 +605,7 @@ static void *sii8620_burst_get_tx_buf(struct
> >> sii8620 *ctx, int len)
> >> u8 *buf = &ctx->burst.tx_buf[ctx->burst.tx_count];
> >> int size = len + 2;
> >> - if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
> >> + if (ctx->burst.tx_count + size >= ARRAY_SIZE(ctx->burst.tx_buf)) {
> >> dev_err(ctx->dev, "TX-BLK buffer exhausted\n");
> >> ctx->error = -EINVAL;
> >> return NULL;
> >> @@ -622,7 +622,7 @@ static u8 *sii8620_burst_get_rx_buf(struct sii8620
> >> *ctx, int len)
> >> u8 *buf = &ctx->burst.rx_buf[ctx->burst.rx_count];
> >> int size = len + 1;
> >> - if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
> >> + if (ctx->burst.rx_count + size >= ARRAY_SIZE(ctx->burst.rx_buf)) {
> >> dev_err(ctx->dev, "RX-BLK buffer exhausted\n");
> >> ctx->error = -EINVAL;
> >> return NULL;
> >
>
> Hi guys,
>
> Another patches for this module that I submitted at the same time as
> this one have been merged. Is this patch forgotten to merge?

Applied to drm-misc-next.