[PATCH net v2] mctp i2c: handle NULL header address

Matt Johnston posted 1 patch 1 month ago
There is a newer version of this series
drivers/net/mctp/mctp-i2c.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
[PATCH net v2] mctp i2c: handle NULL header address
Posted by Matt Johnston 1 month ago
daddr can be NULL if there is no neighbour table entry present,
in that case the tx packet should be dropped.

saddr will normally be set by MCTP core, but in case it is NULL it
should be set to the device address.

Incorrect indent of the function arguments is also fixed.

Fixes: f5b8abf9fc3d ("mctp i2c: MCTP I2C binding driver")
Cc: stable@vger.kernel.org
Reported-by: Dung Cao <dung@os.amperecomputing.com>
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
---
Changes in v2:
- Set saddr to device address if NULL, mention in commit message
- Fix patch prefix formatting
- Link to v1: https://lore.kernel.org/r/20241018-mctp-i2c-null-dest-v1-1-ba1ab52966e9@codeconstruct.com.au
---
 drivers/net/mctp/mctp-i2c.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mctp/mctp-i2c.c b/drivers/net/mctp/mctp-i2c.c
index 4dc057c121f5d0fb9c9c48bf16b6933ae2f7b2ac..c909254e03c21518c17daf8b813e610558e074c1 100644
--- a/drivers/net/mctp/mctp-i2c.c
+++ b/drivers/net/mctp/mctp-i2c.c
@@ -579,7 +579,7 @@ static void mctp_i2c_flow_release(struct mctp_i2c_dev *midev)
 
 static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev,
 				  unsigned short type, const void *daddr,
-	   const void *saddr, unsigned int len)
+				  const void *saddr, unsigned int len)
 {
 	struct mctp_i2c_hdr *hdr;
 	struct mctp_hdr *mhdr;
@@ -588,8 +588,15 @@ static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev,
 	if (len > MCTP_I2C_MAXMTU)
 		return -EMSGSIZE;
 
-	lldst = *((u8 *)daddr);
-	llsrc = *((u8 *)saddr);
+	if (daddr)
+		lldst = *((u8 *)daddr);
+	else
+		return -EINVAL;
+
+	if (saddr)
+		llsrc = *((u8 *)saddr);
+	else
+		llsrc = dev->dev_addr;
 
 	skb_push(skb, sizeof(struct mctp_i2c_hdr));
 	skb_reset_mac_header(skb);

---
base-commit: cb560795c8c2ceca1d36a95f0d1b2eafc4074e37
change-id: 20241018-mctp-i2c-null-dest-a0ba271e0c48

Best regards,
-- 
Matt Johnston <matt@codeconstruct.com.au>
Re: [PATCH net v2] mctp i2c: handle NULL header address
Posted by kernel test robot 1 month ago
Hi Matt,

kernel test robot noticed the following build warnings:

[auto build test WARNING on cb560795c8c2ceca1d36a95f0d1b2eafc4074e37]

url:    https://github.com/intel-lab-lkp/linux/commits/Matt-Johnston/mctp-i2c-handle-NULL-header-address/20241021-123741
base:   cb560795c8c2ceca1d36a95f0d1b2eafc4074e37
patch link:    https://lore.kernel.org/r/20241021-mctp-i2c-null-dest-v2-1-4503e478517c%40codeconstruct.com.au
patch subject: [PATCH net v2] mctp i2c: handle NULL header address
config: alpha-randconfig-r122-20241022 (https://download.01.org/0day-ci/archive/20241022/202410221734.IWc5paM1-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 13.3.0
reproduce: (https://download.01.org/0day-ci/archive/20241022/202410221734.IWc5paM1-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410221734.IWc5paM1-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/net/mctp/mctp-i2c.c:599:23: sparse: sparse: incorrect type in assignment (different base types) @@     expected unsigned char [assigned] [usertype] llsrc @@     got unsigned char const *dev_addr @@
   drivers/net/mctp/mctp-i2c.c:599:23: sparse:     expected unsigned char [assigned] [usertype] llsrc
   drivers/net/mctp/mctp-i2c.c:599:23: sparse:     got unsigned char const *dev_addr
   drivers/net/mctp/mctp-i2c.c: note: in included file (through include/linux/module.h):
   include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true
   include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true

vim +599 drivers/net/mctp/mctp-i2c.c

   579	
   580	static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev,
   581					  unsigned short type, const void *daddr,
   582					  const void *saddr, unsigned int len)
   583	{
   584		struct mctp_i2c_hdr *hdr;
   585		struct mctp_hdr *mhdr;
   586		u8 lldst, llsrc;
   587	
   588		if (len > MCTP_I2C_MAXMTU)
   589			return -EMSGSIZE;
   590	
   591		if (daddr)
   592			lldst = *((u8 *)daddr);
   593		else
   594			return -EINVAL;
   595	
   596		if (saddr)
   597			llsrc = *((u8 *)saddr);
   598		else
 > 599			llsrc = dev->dev_addr;
   600	
   601		skb_push(skb, sizeof(struct mctp_i2c_hdr));
   602		skb_reset_mac_header(skb);
   603		hdr = (void *)skb_mac_header(skb);
   604		mhdr = mctp_hdr(skb);
   605		hdr->dest_slave = (lldst << 1) & 0xff;
   606		hdr->command = MCTP_I2C_COMMANDCODE;
   607		hdr->byte_count = len + 1;
   608		hdr->source_slave = ((llsrc << 1) & 0xff) | 0x01;
   609		mhdr->ver = 0x01;
   610	
   611		return sizeof(struct mctp_i2c_hdr);
   612	}
   613	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH net v2] mctp i2c: handle NULL header address
Posted by kernel test robot 1 month ago
Hi Matt,

kernel test robot noticed the following build errors:

[auto build test ERROR on cb560795c8c2ceca1d36a95f0d1b2eafc4074e37]

url:    https://github.com/intel-lab-lkp/linux/commits/Matt-Johnston/mctp-i2c-handle-NULL-header-address/20241021-123741
base:   cb560795c8c2ceca1d36a95f0d1b2eafc4074e37
patch link:    https://lore.kernel.org/r/20241021-mctp-i2c-null-dest-v2-1-4503e478517c%40codeconstruct.com.au
patch subject: [PATCH net v2] mctp i2c: handle NULL header address
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20241022/202410221036.hs5xBVOp-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241022/202410221036.hs5xBVOp-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410221036.hs5xBVOp-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/net/mctp/mctp-i2c.c:599:9: error: incompatible pointer to integer conversion assigning to 'u8' (aka 'unsigned char') from 'const unsigned char *' [-Wint-conversion]
     599 |                 llsrc = dev->dev_addr;
         |                       ^ ~~~~~~~~~~~~~
   1 error generated.


vim +599 drivers/net/mctp/mctp-i2c.c

   579	
   580	static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev,
   581					  unsigned short type, const void *daddr,
   582					  const void *saddr, unsigned int len)
   583	{
   584		struct mctp_i2c_hdr *hdr;
   585		struct mctp_hdr *mhdr;
   586		u8 lldst, llsrc;
   587	
   588		if (len > MCTP_I2C_MAXMTU)
   589			return -EMSGSIZE;
   590	
   591		if (daddr)
   592			lldst = *((u8 *)daddr);
   593		else
   594			return -EINVAL;
   595	
   596		if (saddr)
   597			llsrc = *((u8 *)saddr);
   598		else
 > 599			llsrc = dev->dev_addr;
   600	
   601		skb_push(skb, sizeof(struct mctp_i2c_hdr));
   602		skb_reset_mac_header(skb);
   603		hdr = (void *)skb_mac_header(skb);
   604		mhdr = mctp_hdr(skb);
   605		hdr->dest_slave = (lldst << 1) & 0xff;
   606		hdr->command = MCTP_I2C_COMMANDCODE;
   607		hdr->byte_count = len + 1;
   608		hdr->source_slave = ((llsrc << 1) & 0xff) | 0x01;
   609		mhdr->ver = 0x01;
   610	
   611		return sizeof(struct mctp_i2c_hdr);
   612	}
   613	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH net v2] mctp i2c: handle NULL header address
Posted by kernel test robot 1 month ago
Hi Matt,

kernel test robot noticed the following build warnings:

[auto build test WARNING on cb560795c8c2ceca1d36a95f0d1b2eafc4074e37]

url:    https://github.com/intel-lab-lkp/linux/commits/Matt-Johnston/mctp-i2c-handle-NULL-header-address/20241021-123741
base:   cb560795c8c2ceca1d36a95f0d1b2eafc4074e37
patch link:    https://lore.kernel.org/r/20241021-mctp-i2c-null-dest-v2-1-4503e478517c%40codeconstruct.com.au
patch subject: [PATCH net v2] mctp i2c: handle NULL header address
config: arc-allmodconfig (https://download.01.org/0day-ci/archive/20241022/202410220730.90gh2nXQ-lkp@intel.com/config)
compiler: arceb-elf-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241022/202410220730.90gh2nXQ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410220730.90gh2nXQ-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/net/mctp/mctp-i2c.c: In function 'mctp_i2c_header_create':
>> drivers/net/mctp/mctp-i2c.c:599:23: warning: assignment to 'u8' {aka 'unsigned char'} from 'const unsigned char *' makes integer from pointer without a cast [-Wint-conversion]
     599 |                 llsrc = dev->dev_addr;
         |                       ^

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for GET_FREE_REGION
   Depends on [n]: SPARSEMEM [=n]
   Selected by [m]:
   - RESOURCE_KUNIT_TEST [=m] && RUNTIME_TESTING_MENU [=y] && KUNIT [=m]


vim +599 drivers/net/mctp/mctp-i2c.c

   579	
   580	static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev,
   581					  unsigned short type, const void *daddr,
   582					  const void *saddr, unsigned int len)
   583	{
   584		struct mctp_i2c_hdr *hdr;
   585		struct mctp_hdr *mhdr;
   586		u8 lldst, llsrc;
   587	
   588		if (len > MCTP_I2C_MAXMTU)
   589			return -EMSGSIZE;
   590	
   591		if (daddr)
   592			lldst = *((u8 *)daddr);
   593		else
   594			return -EINVAL;
   595	
   596		if (saddr)
   597			llsrc = *((u8 *)saddr);
   598		else
 > 599			llsrc = dev->dev_addr;
   600	
   601		skb_push(skb, sizeof(struct mctp_i2c_hdr));
   602		skb_reset_mac_header(skb);
   603		hdr = (void *)skb_mac_header(skb);
   604		mhdr = mctp_hdr(skb);
   605		hdr->dest_slave = (lldst << 1) & 0xff;
   606		hdr->command = MCTP_I2C_COMMANDCODE;
   607		hdr->byte_count = len + 1;
   608		hdr->source_slave = ((llsrc << 1) & 0xff) | 0x01;
   609		mhdr->ver = 0x01;
   610	
   611		return sizeof(struct mctp_i2c_hdr);
   612	}
   613	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH net v2] mctp i2c: handle NULL header address
Posted by kernel test robot 1 month ago
Hi Matt,

kernel test robot noticed the following build errors:

[auto build test ERROR on cb560795c8c2ceca1d36a95f0d1b2eafc4074e37]

url:    https://github.com/intel-lab-lkp/linux/commits/Matt-Johnston/mctp-i2c-handle-NULL-header-address/20241021-123741
base:   cb560795c8c2ceca1d36a95f0d1b2eafc4074e37
patch link:    https://lore.kernel.org/r/20241021-mctp-i2c-null-dest-v2-1-4503e478517c%40codeconstruct.com.au
patch subject: [PATCH net v2] mctp i2c: handle NULL header address
config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20241022/202410220659.hh4B9jRO-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 14.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241022/202410220659.hh4B9jRO-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410220659.hh4B9jRO-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/net/mctp/mctp-i2c.c: In function 'mctp_i2c_header_create':
>> drivers/net/mctp/mctp-i2c.c:599:23: error: assignment to 'u8' {aka 'unsigned char'} from 'const unsigned char *' makes integer from pointer without a cast [-Wint-conversion]
     599 |                 llsrc = dev->dev_addr;
         |                       ^

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for GET_FREE_REGION
   Depends on [n]: SPARSEMEM [=n]
   Selected by [m]:
   - RESOURCE_KUNIT_TEST [=m] && RUNTIME_TESTING_MENU [=y] && KUNIT [=m]


vim +599 drivers/net/mctp/mctp-i2c.c

   579	
   580	static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev,
   581					  unsigned short type, const void *daddr,
   582					  const void *saddr, unsigned int len)
   583	{
   584		struct mctp_i2c_hdr *hdr;
   585		struct mctp_hdr *mhdr;
   586		u8 lldst, llsrc;
   587	
   588		if (len > MCTP_I2C_MAXMTU)
   589			return -EMSGSIZE;
   590	
   591		if (daddr)
   592			lldst = *((u8 *)daddr);
   593		else
   594			return -EINVAL;
   595	
   596		if (saddr)
   597			llsrc = *((u8 *)saddr);
   598		else
 > 599			llsrc = dev->dev_addr;
   600	
   601		skb_push(skb, sizeof(struct mctp_i2c_hdr));
   602		skb_reset_mac_header(skb);
   603		hdr = (void *)skb_mac_header(skb);
   604		mhdr = mctp_hdr(skb);
   605		hdr->dest_slave = (lldst << 1) & 0xff;
   606		hdr->command = MCTP_I2C_COMMANDCODE;
   607		hdr->byte_count = len + 1;
   608		hdr->source_slave = ((llsrc << 1) & 0xff) | 0x01;
   609		mhdr->ver = 0x01;
   610	
   611		return sizeof(struct mctp_i2c_hdr);
   612	}
   613	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH net v2] mctp i2c: handle NULL header address
Posted by Simon Horman 1 month ago
On Mon, Oct 21, 2024 at 12:35:26PM +0800, Matt Johnston wrote:
> daddr can be NULL if there is no neighbour table entry present,
> in that case the tx packet should be dropped.
> 
> saddr will normally be set by MCTP core, but in case it is NULL it
> should be set to the device address.
> 
> Incorrect indent of the function arguments is also fixed.
> 
> Fixes: f5b8abf9fc3d ("mctp i2c: MCTP I2C binding driver")
> Cc: stable@vger.kernel.org
> Reported-by: Dung Cao <dung@os.amperecomputing.com>
> Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
> ---
> Changes in v2:
> - Set saddr to device address if NULL, mention in commit message
> - Fix patch prefix formatting
> - Link to v1: https://lore.kernel.org/r/20241018-mctp-i2c-null-dest-v1-1-ba1ab52966e9@codeconstruct.com.au
> ---
>  drivers/net/mctp/mctp-i2c.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/mctp/mctp-i2c.c b/drivers/net/mctp/mctp-i2c.c
> index 4dc057c121f5d0fb9c9c48bf16b6933ae2f7b2ac..c909254e03c21518c17daf8b813e610558e074c1 100644
> --- a/drivers/net/mctp/mctp-i2c.c
> +++ b/drivers/net/mctp/mctp-i2c.c
> @@ -579,7 +579,7 @@ static void mctp_i2c_flow_release(struct mctp_i2c_dev *midev)
>  
>  static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev,
>  				  unsigned short type, const void *daddr,
> -	   const void *saddr, unsigned int len)
> +				  const void *saddr, unsigned int len)
>  {
>  	struct mctp_i2c_hdr *hdr;
>  	struct mctp_hdr *mhdr;

Hi Matt,

I think you should drop this hunk.
While it's nice to clean things up, in the context of other work [1],
this isn't really appropriate as part of a fix for net.

[1] https://docs.kernel.org/process/maintainer-netdev.html#clean-up-patches

> @@ -588,8 +588,15 @@ static int mctp_i2c_header_create(struct sk_buff *skb, struct net_device *dev,
>  	if (len > MCTP_I2C_MAXMTU)
>  		return -EMSGSIZE;
>  
> -	lldst = *((u8 *)daddr);
> -	llsrc = *((u8 *)saddr);
> +	if (daddr)
> +		lldst = *((u8 *)daddr);
> +	else
> +		return -EINVAL;
> +
> +	if (saddr)
> +		llsrc = *((u8 *)saddr);
> +	else
> +		llsrc = dev->dev_addr;

This last line doesn't seem right, as llsrc is a u8,
while dev->dev_addr is a pointer to unsigned char.

>  
>  	skb_push(skb, sizeof(struct mctp_i2c_hdr));
>  	skb_reset_mac_header(skb);

-- 
pw-bot: changes-requested