CVE-2024-49995: tipc: guard against string buffer overrun

CVE-2024-49995: tipc: guard against string buffer overrun

[Greg Kroah-Hartman]

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

tipc: guard against string buffer overrun

Smatch reports that copying media_name and if_name to name_parts may
overwrite the destination.

 .../bearer.c:166 bearer_name_validate() error: strcpy() 'media_name' too large for 'name_parts->media_name' (32 vs 16)
 .../bearer.c:167 bearer_name_validate() error: strcpy() 'if_name' too large for 'name_parts->if_name' (1010102 vs 16)

This does seem to be the case so guard against this possibility by using
strscpy() and failing if truncation occurs.

Introduced by commit b97bf3fd8f6a ("[TIPC] Initial merge")

Compile tested only.

The Linux kernel CVE team has assigned CVE-2024-49995 to this issue.


Affected and fixed versions
===========================

	Fixed in 5.10.227 with commit e2b2558971e0
	Fixed in 5.15.168 with commit 54dae0e9063e
	Fixed in 6.1.113 with commit 80c0be7bcf94
	Fixed in 6.6.55 with commit 12d26aa7fd3c
	Fixed in 6.10.14 with commit 2ed7f42dfd3e
	Fixed in 6.11.3 with commit a18c7b239d02
	Fixed in 6.12-rc1 with commit 6555a2a9212b

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-49995
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	net/tipc/bearer.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/e2b2558971e02ca33eb637a8350d68a48b3e8e46
	https://git.kernel.org/stable/c/54dae0e9063ed23c9acf8d5ab9b18d3426a8ac18
	https://git.kernel.org/stable/c/80c0be7bcf940ce9308311575c3aff8983c9b97a
	https://git.kernel.org/stable/c/12d26aa7fd3cbdbc5149b6e516563478d575026e
	https://git.kernel.org/stable/c/2ed7f42dfd3edb387034128ca5b0f639836d4ddd
	https://git.kernel.org/stable/c/a18c7b239d02aafb791ae2c45226f6bb40641792
	https://git.kernel.org/stable/c/6555a2a9212be6983d2319d65276484f7c5f431a

Re: CVE-2024-49995: tipc: guard against string buffer overrun

[Harshit Mogalapalli]

Hi,

On 21/10/24 23:33, Greg Kroah-Hartman wrote:
> Description
> ===========
> 
> In the Linux kernel, the following vulnerability has been resolved:
> 
> tipc: guard against string buffer overrun
> 
> Smatch reports that copying media_name and if_name to name_parts may
> overwrite the destination.
> 
>   .../bearer.c:166 bearer_name_validate() error: strcpy() 'media_name' too large for 'name_parts->media_name' (32 vs 16)
>   .../bearer.c:167 bearer_name_validate() error: strcpy() 'if_name' too large for 'name_parts->if_name' (1010102 vs 16)
> 
> This does seem to be the case so guard against this possibility by using
> strscpy() and failing if truncation occurs.
> 
> Introduced by commit b97bf3fd8f6a ("[TIPC] Initial merge")
> 
> Compile tested only.
> 
> The Linux kernel CVE team has assigned CVE-2024-49995 to this issue.
> 
> 

Looking at the fix commit with more lines around the fix:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6555a2a9212be6983d2319d65276484f7c5f431a&context=30


  	/* validate component parts of bearer name */
  	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
  	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
  		return 0;

  	/* return bearer name components, if necessary */
  	if (name_parts) {
-		strcpy(name_parts->media_name, media_name);
-		strcpy(name_parts->if_name, if_name);
+		if (strscpy(name_parts->media_name, media_name,
+			    TIPC_MAX_MEDIA_NAME) < 0)
+			return 0;
+		if (strscpy(name_parts->if_name, if_name,
+			    TIPC_MAX_IF_NAME) < 0)
+			return 0;
  	}
  	return 1;



both media_len and if_len have validation checks above the 
if(name_parts) check. So I think this patch just silences the static 
checker warnings.

Simon/Dan , could you please help confirming that ?

Thanks,
Harshit

> Affected and fixed versions
> ===========================
> 
> 	Fixed in 5.10.227 with commit e2b2558971e0
> 	Fixed in 5.15.168 with commit 54dae0e9063e
> 	Fixed in 6.1.113 with commit 80c0be7bcf94
> 	Fixed in 6.6.55 with commit 12d26aa7fd3c
> 	Fixed in 6.10.14 with commit 2ed7f42dfd3e
> 	Fixed in 6.11.3 with commit a18c7b239d02
> 	Fixed in 6.12-rc1 with commit 6555a2a9212b
> 
> Please see https://www.kernel.org for a full list of currently supported
> kernel versions by the kernel community.
> 
> Unaffected versions might change over time as fixes are backported to
> older supported kernel versions.  The official CVE entry at
> 	https://cve.org/CVERecord/?id=CVE-2024-49995
> will be updated if fixes are backported, please check that for the most
> up to date information about this issue.
> 
> 
> Affected files
> ==============
> 
> The file(s) affected by this issue are:
> 	net/tipc/bearer.c
> 
> 
> Mitigation
> ==========
> 
> The Linux kernel CVE team recommends that you update to the latest
> stable kernel version for this, and many other bugfixes.  Individual
> changes are never tested alone, but rather are part of a larger kernel
> release.  Cherry-picking individual commits is not recommended or
> supported by the Linux kernel community at all.  If however, updating to
> the latest release is impossible, the individual changes to resolve this
> issue can be found at these commits:
> 	https://git.kernel.org/stable/c/e2b2558971e02ca33eb637a8350d68a48b3e8e46
> 	https://git.kernel.org/stable/c/54dae0e9063ed23c9acf8d5ab9b18d3426a8ac18
> 	https://git.kernel.org/stable/c/80c0be7bcf940ce9308311575c3aff8983c9b97a
> 	https://git.kernel.org/stable/c/12d26aa7fd3cbdbc5149b6e516563478d575026e
> 	https://git.kernel.org/stable/c/2ed7f42dfd3edb387034128ca5b0f639836d4ddd
> 	https://git.kernel.org/stable/c/a18c7b239d02aafb791ae2c45226f6bb40641792
> 	https://git.kernel.org/stable/c/6555a2a9212be6983d2319d65276484f7c5f431a

Re: CVE-2024-49995: tipc: guard against string buffer overrun

[Simon Horman]

- me at corigine.com
+ netdev

On Thu, Apr 24, 2025 at 11:41:01AM +0530, Harshit Mogalapalli wrote:
> Hi,
> 
> On 21/10/24 23:33, Greg Kroah-Hartman wrote:
> > Description
> > ===========
> > 
> > In the Linux kernel, the following vulnerability has been resolved:
> > 
> > tipc: guard against string buffer overrun
> > 
> > Smatch reports that copying media_name and if_name to name_parts may
> > overwrite the destination.
> > 
> >   .../bearer.c:166 bearer_name_validate() error: strcpy() 'media_name' too large for 'name_parts->media_name' (32 vs 16)
> >   .../bearer.c:167 bearer_name_validate() error: strcpy() 'if_name' too large for 'name_parts->if_name' (1010102 vs 16)
> > 
> > This does seem to be the case so guard against this possibility by using
> > strscpy() and failing if truncation occurs.
> > 
> > Introduced by commit b97bf3fd8f6a ("[TIPC] Initial merge")
> > 
> > Compile tested only.
> > 
> > The Linux kernel CVE team has assigned CVE-2024-49995 to this issue.
> > 
> > 
> 
> Looking at the fix commit with more lines around the fix:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6555a2a9212be6983d2319d65276484f7c5f431a&context=30
> 
> 
>  	/* validate component parts of bearer name */
>  	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
>  	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
>  		return 0;
> 
>  	/* return bearer name components, if necessary */
>  	if (name_parts) {
> -		strcpy(name_parts->media_name, media_name);
> -		strcpy(name_parts->if_name, if_name);
> +		if (strscpy(name_parts->media_name, media_name,
> +			    TIPC_MAX_MEDIA_NAME) < 0)
> +			return 0;
> +		if (strscpy(name_parts->if_name, if_name,
> +			    TIPC_MAX_IF_NAME) < 0)
> +			return 0;
>  	}
>  	return 1;
> 
> 
> 
> both media_len and if_len have validation checks above the if(name_parts)
> check. So I think this patch just silences the static checker warnings.
> 
> Simon/Dan , could you please help confirming that ?

Thanks Harshit,

Looking over this with fresh eyes this morning I agree with your analysis.

I can't be sure what I was thinking regarding this being a bug when I
posted the patch in August. But that it was for net-next, rather than net,
and had no Fixes tag, indicates that I did not feel that it was a bug fix at
the time.

https://lore.kernel.org/netdev/20240801-tipic-overrun-v2-1-c5b869d1f074@kernel.org/

In any case, I don't think it is a bug fix now.


> 
> Thanks,
> Harshit
> 
> > Affected and fixed versions
> > ===========================
> > 
> > 	Fixed in 5.10.227 with commit e2b2558971e0
> > 	Fixed in 5.15.168 with commit 54dae0e9063e
> > 	Fixed in 6.1.113 with commit 80c0be7bcf94
> > 	Fixed in 6.6.55 with commit 12d26aa7fd3c
> > 	Fixed in 6.10.14 with commit 2ed7f42dfd3e
> > 	Fixed in 6.11.3 with commit a18c7b239d02
> > 	Fixed in 6.12-rc1 with commit 6555a2a9212b
> > 
> > Please see https://www.kernel.org for a full list of currently supported
> > kernel versions by the kernel community.
> > 
> > Unaffected versions might change over time as fixes are backported to
> > older supported kernel versions.  The official CVE entry at
> > 	https://cve.org/CVERecord/?id=CVE-2024-49995
> > will be updated if fixes are backported, please check that for the most
> > up to date information about this issue.
> > 
> > 
> > Affected files
> > ==============
> > 
> > The file(s) affected by this issue are:
> > 	net/tipc/bearer.c
> > 
> > 
> > Mitigation
> > ==========
> > 
> > The Linux kernel CVE team recommends that you update to the latest
> > stable kernel version for this, and many other bugfixes.  Individual
> > changes are never tested alone, but rather are part of a larger kernel
> > release.  Cherry-picking individual commits is not recommended or
> > supported by the Linux kernel community at all.  If however, updating to
> > the latest release is impossible, the individual changes to resolve this
> > issue can be found at these commits:
> > 	https://git.kernel.org/stable/c/e2b2558971e02ca33eb637a8350d68a48b3e8e46
> > 	https://git.kernel.org/stable/c/54dae0e9063ed23c9acf8d5ab9b18d3426a8ac18
> > 	https://git.kernel.org/stable/c/80c0be7bcf940ce9308311575c3aff8983c9b97a
> > 	https://git.kernel.org/stable/c/12d26aa7fd3cbdbc5149b6e516563478d575026e
> > 	https://git.kernel.org/stable/c/2ed7f42dfd3edb387034128ca5b0f639836d4ddd
> > 	https://git.kernel.org/stable/c/a18c7b239d02aafb791ae2c45226f6bb40641792
> > 	https://git.kernel.org/stable/c/6555a2a9212be6983d2319d65276484f7c5f431a
> 

Re: CVE-2024-49995: tipc: guard against string buffer overrun

[Dan Carpenter]

On Thu, Apr 24, 2025 at 11:41:01AM +0530, Harshit Mogalapalli wrote:
> Hi,
> 
> On 21/10/24 23:33, Greg Kroah-Hartman wrote:
> > Description
> > ===========
> > 
> > In the Linux kernel, the following vulnerability has been resolved:
> > 
> > tipc: guard against string buffer overrun
> > 
> > Smatch reports that copying media_name and if_name to name_parts may
> > overwrite the destination.
> > 
> >   .../bearer.c:166 bearer_name_validate() error: strcpy() 'media_name' too large for 'name_parts->media_name' (32 vs 16)
> >   .../bearer.c:167 bearer_name_validate() error: strcpy() 'if_name' too large for 'name_parts->if_name' (1010102 vs 16)
> > 
> > This does seem to be the case so guard against this possibility by using
> > strscpy() and failing if truncation occurs.
> > 
> > Introduced by commit b97bf3fd8f6a ("[TIPC] Initial merge")
> > 
> > Compile tested only.
> > 
> > The Linux kernel CVE team has assigned CVE-2024-49995 to this issue.
> > 
> > 
> 
> Looking at the fix commit with more lines around the fix:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6555a2a9212be6983d2319d65276484f7c5f431a&context=30
> 
> 
>  	/* validate component parts of bearer name */
>  	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
>  	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
>  		return 0;
> 
>  	/* return bearer name components, if necessary */
>  	if (name_parts) {
> -		strcpy(name_parts->media_name, media_name);
> -		strcpy(name_parts->if_name, if_name);
> +		if (strscpy(name_parts->media_name, media_name,
> +			    TIPC_MAX_MEDIA_NAME) < 0)
> +			return 0;
> +		if (strscpy(name_parts->if_name, if_name,
> +			    TIPC_MAX_IF_NAME) < 0)
> +			return 0;
>  	}
>  	return 1;
> 
> 
> 
> both media_len and if_len have validation checks above the if(name_parts)
> check. So I think this patch just silences the static checker warnings.
> 
> Simon/Dan , could you please help confirming that ?

Correct.  The "validate component parts of bearer name" checks are
sufficient.  This will not affect runtime.

regards,
dan carpenter

Re: CVE-2024-49995: tipc: guard against string buffer overrun

[Harshit Mogalapalli]

Hi,


On 24/04/25 13:47, Dan Carpenter wrote:
> On Thu, Apr 24, 2025 at 11:41:01AM +0530, Harshit Mogalapalli wrote:
...
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6555a2a9212be6983d2319d65276484f7c5f431a&context=30
>>
>>
>>   	/* validate component parts of bearer name */
>>   	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
>>   	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
>>   		return 0;
>>
>>   	/* return bearer name components, if necessary */
>>   	if (name_parts) {
>> -		strcpy(name_parts->media_name, media_name);
>> -		strcpy(name_parts->if_name, if_name);
>> +		if (strscpy(name_parts->media_name, media_name,
>> +			    TIPC_MAX_MEDIA_NAME) < 0)
>> +			return 0;
>> +		if (strscpy(name_parts->if_name, if_name,
>> +			    TIPC_MAX_IF_NAME) < 0)
>> +			return 0;
>>   	}
>>   	return 1;
>>
>>
>>
>> both media_len and if_len have validation checks above the if(name_parts)
>> check. So I think this patch just silences the static checker warnings.
>>
>> Simon/Dan , could you please help confirming that ?
> 
> Correct.  The "validate component parts of bearer name" checks are
> sufficient.  This will not affect runtime.
> 

Thanks a lot Dan and Simon for confirming this.

Greg: Should we get this CVE-2024-49995 revoked ?


Regards,
Harshit
> regards,
> dan carpenter
> 

Re: CVE-2024-49995: tipc: guard against string buffer overrun

[Greg Kroah-Hartman]

On Thu, Apr 24, 2025 at 02:15:43PM +0530, Harshit Mogalapalli wrote:
> Hi,
> 
> 
> On 24/04/25 13:47, Dan Carpenter wrote:
> > On Thu, Apr 24, 2025 at 11:41:01AM +0530, Harshit Mogalapalli wrote:
> ...
> > > 
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6555a2a9212be6983d2319d65276484f7c5f431a&context=30
> > > 
> > > 
> > >   	/* validate component parts of bearer name */
> > >   	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
> > >   	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
> > >   		return 0;
> > > 
> > >   	/* return bearer name components, if necessary */
> > >   	if (name_parts) {
> > > -		strcpy(name_parts->media_name, media_name);
> > > -		strcpy(name_parts->if_name, if_name);
> > > +		if (strscpy(name_parts->media_name, media_name,
> > > +			    TIPC_MAX_MEDIA_NAME) < 0)
> > > +			return 0;
> > > +		if (strscpy(name_parts->if_name, if_name,
> > > +			    TIPC_MAX_IF_NAME) < 0)
> > > +			return 0;
> > >   	}
> > >   	return 1;
> > > 
> > > 
> > > 
> > > both media_len and if_len have validation checks above the if(name_parts)
> > > check. So I think this patch just silences the static checker warnings.
> > > 
> > > Simon/Dan , could you please help confirming that ?
> > 
> > Correct.  The "validate component parts of bearer name" checks are
> > sufficient.  This will not affect runtime.
> > 
> 
> Thanks a lot Dan and Simon for confirming this.
> 
> Greg: Should we get this CVE-2024-49995 revoked ?

Yup, now rejected, thanks for the review!

greg k-h