diff mbox series

[05/24] media: dvb-usb-v2: ec168: fix null-ptr-deref in ec168_i2c_xfer()

Message ID 7ced9f219d36cb0d3319b556dc0b0f4f81247fa6.1684000646.git.mchehab@kernel.org
State New
Headers
Series [01/24] media: pvrusb2: fix DVB_CORE dependency |

Commit Message

Mauro Carvalho Chehab May 13, 2023, 5:57 p.m. UTC 
  From: Wei Chen <harperchen1110@gmail.com>

In ec168_i2c_xfer, msg is controlled by user. When msg[i].buf is null
and msg[i].len is zero, former checks on msg[i].buf would be passed.
If accessing msg[i].buf[0] without sanity check, null pointer deref
would happen. We add check on msg[i].len to prevent crash.

Similar commit:
commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")

Link: https://lore.kernel.org/linux-media/20230313085853.3252349-1-harperchen1110@gmail.com
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
---
 drivers/media/usb/dvb-usb-v2/ec168.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Comments

Matthias Schwarzott May 17, 2023, 5:10 a.m. UTC | #1 
Am 13.05.23 um 19:57 schrieb Mauro Carvalho Chehab:
> From: Wei Chen <harperchen1110@gmail.com>
> 
> In ec168_i2c_xfer, msg is controlled by user. When msg[i].buf is null
> and msg[i].len is zero, former checks on msg[i].buf would be passed.
> If accessing msg[i].buf[0] without sanity check, null pointer deref
> would happen. We add check on msg[i].len to prevent crash.
> 
> Similar commit:
> commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")
> 
Review comment below.

> Link: https://lore.kernel.org/linux-media/20230313085853.3252349-1-harperchen1110@gmail.com
> Signed-off-by: Wei Chen <harperchen1110@gmail.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
> ---
>   drivers/media/usb/dvb-usb-v2/ec168.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/media/usb/dvb-usb-v2/ec168.c b/drivers/media/usb/dvb-usb-v2/ec168.c
> index 7ed0ab9e429b..0e4773fc025c 100644
> --- a/drivers/media/usb/dvb-usb-v2/ec168.c
> +++ b/drivers/media/usb/dvb-usb-v2/ec168.c
> @@ -115,6 +115,10 @@ static int ec168_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
>   	while (i < num) {
>   		if (num > i + 1 && (msg[i+1].flags & I2C_M_RD)) {
>   			if (msg[i].addr == ec168_ec100_config.demod_address) {
> +				if (msg[i].len < 1) {
> +					i = -EOPNOTSUPP;
> +					break;
> +				}
>   				req.cmd = READ_DEMOD;
>   				req.value = 0;
>   				req.index = 0xff00 + msg[i].buf[0]; /* reg */
> @@ -131,6 +135,10 @@ static int ec168_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
>   			}
>   		} else {
>   			if (msg[i].addr == ec168_ec100_config.demod_address) {
> +				if (msg[i].len < 1) {
> +					i = -EOPNOTSUPP;
> +					break;
> +				}
The check condition should be msg[i].len < 2 or != 2. The following 
lines access msg[i].buf elements 0 and 1.
>   				req.cmd = WRITE_DEMOD;
>   				req.value = msg[i].buf[1]; /* val */
>   				req.index = 0xff00 + msg[i].buf[0]; /* reg */
> @@ -139,6 +147,10 @@ static int ec168_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
>   				ret = ec168_ctrl_msg(d, &req);
>   				i += 1;
>   			} else {
> +				if (msg[i].len < 1) {
> +					i = -EOPNOTSUPP;
> +					break;
> +				}
>   				req.cmd = WRITE_I2C;
>   				req.value = msg[i].buf[0]; /* val */
>   				req.index = 0x0100 + msg[i].addr; /* I2C addr */
Wei Chen May 19, 2023, 9:17 a.m. UTC | #2 
Dear Linux Developers,

Thank you for the review for my patch in driver az6027 and ec168.

Yes, I agree with you. Sorry for my mistake. Since these two patches has already been accepted and merged in git tree media, should I send a new patch to revise this problem? Or how could I revise an accepted patch?

Thanks,
Wei


------ Original Message ------
From zzam@gentoo.org
To "Mauro Carvalho Chehab" <mchehab@kernel.org>
Cc "Wei Chen" <harperchen1110@gmail.com>; "Antti Palosaari" <crope@iki.fi>; linux-kernel@vger.kernel.org; linux-media@vger.kernel.org
Date 2023/5/17 13:10:34
Subject Re: [PATCH 05/24] media: dvb-usb-v2: ec168: fix null-ptr-deref in ec168_i2c_xfer()

>Am 13.05.23 um 19:57 schrieb Mauro Carvalho Chehab:
>>From: Wei Chen <harperchen1110@gmail.com>
>>
>>In ec168_i2c_xfer, msg is controlled by user. When msg[i].buf is null
>>and msg[i].len is zero, former checks on msg[i].buf would be passed.
>>If accessing msg[i].buf[0] without sanity check, null pointer deref
>>would happen. We add check on msg[i].len to prevent crash.
>>
>>Similar commit:
>>commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")
>>
>Review comment below.
>
>>Link: https://lore.kernel.org/linux-media/20230313085853.3252349-1-harperchen1110@gmail.com
>>Signed-off-by: Wei Chen <harperchen1110@gmail.com>
>>Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
>>---
>>   drivers/media/usb/dvb-usb-v2/ec168.c | 12 ++++++++++++
>>   1 file changed, 12 insertions(+)
>>
>>diff --git a/drivers/media/usb/dvb-usb-v2/ec168.c b/drivers/media/usb/dvb-usb-v2/ec168.c
>>index 7ed0ab9e429b..0e4773fc025c 100644
>>--- a/drivers/media/usb/dvb-usb-v2/ec168.c
>>+++ b/drivers/media/usb/dvb-usb-v2/ec168.c
>>@@ -115,6 +115,10 @@ static int ec168_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
>>   	while (i < num) {
>>   		if (num > i + 1 && (msg[i+1].flags & I2C_M_RD)) {
>>   			if (msg[i].addr == ec168_ec100_config.demod_address) {
>>+				if (msg[i].len < 1) {
>>+					i = -EOPNOTSUPP;
>>+					break;
>>+				}
>>   				req.cmd = READ_DEMOD;
>>   				req.value = 0;
>>   				req.index = 0xff00 + msg[i].buf[0]; /* reg */
>>@@ -131,6 +135,10 @@ static int ec168_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
>>   			}
>>   		} else {
>>   			if (msg[i].addr == ec168_ec100_config.demod_address) {
>>+				if (msg[i].len < 1) {
>>+					i = -EOPNOTSUPP;
>>+					break;
>>+				}
>The check condition should be msg[i].len < 2 or != 2. The following lines access msg[i].buf elements 0 and 1.
>>   				req.cmd = WRITE_DEMOD;
>>   				req.value = msg[i].buf[1]; /* val */
>>   				req.index = 0xff00 + msg[i].buf[0]; /* reg */
>>@@ -139,6 +147,10 @@ static int ec168_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
>>   				ret = ec168_ctrl_msg(d, &req);
>>   				i += 1;
>>   			} else {
>>+				if (msg[i].len < 1) {
>>+					i = -EOPNOTSUPP;
>>+					break;
>>+				}
>>   				req.cmd = WRITE_I2C;
>>   				req.value = msg[i].buf[0]; /* val */
>>   				req.index = 0x0100 + msg[i].addr; /* I2C addr */
>
Matthias Schwarzott June 2, 2023, 6:41 a.m. UTC | #3 
Am 19.05.23 um 11:17 schrieb Wei Chen:
> Dear Linux Developers,
> 
Hi Wei,
> Thank you for the review for my patch in driver az6027 and ec168.
> 
> Yes, I agree with you. Sorry for my mistake. Since these two patches has 
> already been accepted and merged in git tree media, should I send a new 
> patch to revise this problem? Or how could I revise an accepted patch?

I think the best is to send new patches on top of the already accepted 
patches.

Regards
Matthias


> 
> Thanks,
> Wei
> 
> 
> ------ Original Message ------
>> From zzam@gentoo.org
> To "Mauro Carvalho Chehab" <mchehab@kernel.org>
> Cc "Wei Chen" <harperchen1110@gmail.com>; "Antti Palosaari" 
> <crope@iki.fi>; linux-kernel@vger.kernel.org; linux-media@vger.kernel.org
> Date 2023/5/17 13:10:34
> Subject Re: [PATCH 05/24] media: dvb-usb-v2: ec168: fix null-ptr-deref 
> in ec168_i2c_xfer()
> 
>> Am 13.05.23 um 19:57 schrieb Mauro Carvalho Chehab:
>>> From: Wei Chen <harperchen1110@gmail.com>
>>>
>>> In ec168_i2c_xfer, msg is controlled by user. When msg[i].buf is null
>>> and msg[i].len is zero, former checks on msg[i].buf would be passed.
>>> If accessing msg[i].buf[0] without sanity check, null pointer deref
>>> would happen. We add check on msg[i].len to prevent crash.
>>>
>>> Similar commit:
>>> commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in 
>>> az6027_i2c_xfer()")
>>>
>> Review comment below.
>>
>>> Link: 
>>> https://lore.kernel.org/linux-media/20230313085853.3252349-1-harperchen1110@gmail.com
>>> Signed-off-by: Wei Chen <harperchen1110@gmail.com>
>>> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
>>> ---
>>>   drivers/media/usb/dvb-usb-v2/ec168.c | 12 ++++++++++++
>>>   1 file changed, 12 insertions(+)
>>>
>>> diff --git a/drivers/media/usb/dvb-usb-v2/ec168.c 
>>> b/drivers/media/usb/dvb-usb-v2/ec168.c
>>> index 7ed0ab9e429b..0e4773fc025c 100644
>>> --- a/drivers/media/usb/dvb-usb-v2/ec168.c
>>> +++ b/drivers/media/usb/dvb-usb-v2/ec168.c
>>> @@ -115,6 +115,10 @@ static int ec168_i2c_xfer(struct i2c_adapter 
>>> *adap, struct i2c_msg msg[],
>>>       while (i < num) {
>>>           if (num > i + 1 && (msg[i+1].flags & I2C_M_RD)) {
>>>               if (msg[i].addr == ec168_ec100_config.demod_address) {
>>> +                if (msg[i].len < 1) {
>>> +                    i = -EOPNOTSUPP;
>>> +                    break;
>>> +                }
>>>                   req.cmd = READ_DEMOD;
>>>                   req.value = 0;
>>>                   req.index = 0xff00 + msg[i].buf[0]; /* reg */
>>> @@ -131,6 +135,10 @@ static int ec168_i2c_xfer(struct i2c_adapter 
>>> *adap, struct i2c_msg msg[],
>>>               }
>>>           } else {
>>>               if (msg[i].addr == ec168_ec100_config.demod_address) {
>>> +                if (msg[i].len < 1) {
>>> +                    i = -EOPNOTSUPP;
>>> +                    break;
>>> +                }
>> The check condition should be msg[i].len < 2 or != 2. The following 
>> lines access msg[i].buf elements 0 and 1.
>>>                   req.cmd = WRITE_DEMOD;
>>>                   req.value = msg[i].buf[1]; /* val */
>>>                   req.index = 0xff00 + msg[i].buf[0]; /* reg */
>>> @@ -139,6 +147,10 @@ static int ec168_i2c_xfer(struct i2c_adapter 
>>> *adap, struct i2c_msg msg[],
>>>                   ret = ec168_ctrl_msg(d, &req);
>>>                   i += 1;
>>>               } else {
>>> +                if (msg[i].len < 1) {
>>> +                    i = -EOPNOTSUPP;
>>> +                    break;
>>> +                }
>>>                   req.cmd = WRITE_I2C;
>>>                   req.value = msg[i].buf[0]; /* val */
>>>                   req.index = 0x0100 + msg[i].addr; /* I2C addr */
>>
diff mbox series

Patch

diff --git a/drivers/media/usb/dvb-usb-v2/ec168.c b/drivers/media/usb/dvb-usb-v2/ec168.c
index 7ed0ab9e429b..0e4773fc025c 100644
--- a/drivers/media/usb/dvb-usb-v2/ec168.c
+++ b/drivers/media/usb/dvb-usb-v2/ec168.c
@@ -115,6 +115,10 @@  static int ec168_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
 	while (i < num) {
 		if (num > i + 1 && (msg[i+1].flags & I2C_M_RD)) {
 			if (msg[i].addr == ec168_ec100_config.demod_address) {
+				if (msg[i].len < 1) {
+					i = -EOPNOTSUPP;
+					break;
+				}
 				req.cmd = READ_DEMOD;
 				req.value = 0;
 				req.index = 0xff00 + msg[i].buf[0]; /* reg */
@@ -131,6 +135,10 @@  static int ec168_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
 			}
 		} else {
 			if (msg[i].addr == ec168_ec100_config.demod_address) {
+				if (msg[i].len < 1) {
+					i = -EOPNOTSUPP;
+					break;
+				}
 				req.cmd = WRITE_DEMOD;
 				req.value = msg[i].buf[1]; /* val */
 				req.index = 0xff00 + msg[i].buf[0]; /* reg */
@@ -139,6 +147,10 @@  static int ec168_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
 				ret = ec168_ctrl_msg(d, &req);
 				i += 1;
 			} else {
+				if (msg[i].len < 1) {
+					i = -EOPNOTSUPP;
+					break;
+				}
 				req.cmd = WRITE_I2C;
 				req.value = msg[i].buf[0]; /* val */
 				req.index = 0x0100 + msg[i].addr; /* I2C addr */