Patchwork [maverick,maverick/ti-omap4,CVE,1/1] Fix corrupted OSF partition table parsing

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Submitter Andy Whitcroft
Date June 13, 2011, 2:03 p.m.
Message ID <1307973817-5773-3-git-send-email-apw@canonical.com>
Download mbox | patch
Permalink /patch/100162/
State New
Headers show

Comments

Andy Whitcroft - June 13, 2011, 2:03 p.m.
From: Timo Warns <Warns@pre-sense.de>

The kernel automatically evaluates partition tables of storage devices.
The code for evaluating OSF partitions contains a bug that leaks data
from kernel heap memory to userspace for certain corrupted OSF
partitions.

In more detail:

  for (i = 0 ; i < le16_to_cpu(label->d_npartitions); i++, partition++) {

iterates from 0 to d_npartitions - 1, where d_npartitions is read from
the partition table without validation and partition is a pointer to an
array of at most 8 d_partitions.

Add the proper and obvious validation.

Signed-off-by: Timo Warns <warns@pre-sense.de>
Cc: stable@kernel.org
[ Changed the patch trivially to not repeat the whole le16_to_cpu()
  thing, and to use an explicit constant for the magic value '8' ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit 1eafbfeb7bdf59cfe173304c76188f3fd5f1fd05)
CVE-2011-1163
BugLink: http://bugs.launchpad.net/bugs/796606
Signed-off-by: Andy Whitcroft <apw@canonical.com>
---
 fs/partitions/osf.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)
Leann Ogasawara - June 13, 2011, 6:06 p.m.
On Mon, 2011-06-13 at 15:03 +0100, Andy Whitcroft wrote:
> From: Timo Warns <Warns@pre-sense.de>
> 
> The kernel automatically evaluates partition tables of storage devices.
> The code for evaluating OSF partitions contains a bug that leaks data
> from kernel heap memory to userspace for certain corrupted OSF
> partitions.
> 
> In more detail:
> 
>   for (i = 0 ; i < le16_to_cpu(label->d_npartitions); i++, partition++) {
> 
> iterates from 0 to d_npartitions - 1, where d_npartitions is read from
> the partition table without validation and partition is a pointer to an
> array of at most 8 d_partitions.
> 
> Add the proper and obvious validation.
> 
> Signed-off-by: Timo Warns <warns@pre-sense.de>
> Cc: stable@kernel.org
> [ Changed the patch trivially to not repeat the whole le16_to_cpu()
>   thing, and to use an explicit constant for the magic value '8' ]
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> 
> (cherry picked from commit 1eafbfeb7bdf59cfe173304c76188f3fd5f1fd05)
> CVE-2011-1163
> BugLink: http://bugs.launchpad.net/bugs/796606
> Signed-off-by: Andy Whitcroft <apw@canonical.com>

Acked-by: Leann Ogasawara <leann.ogasawara@canonical.com>

> ---
>  fs/partitions/osf.c |   12 ++++++++++--
>  1 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/partitions/osf.c b/fs/partitions/osf.c
> index fc22b85..5b49d40 100644
> --- a/fs/partitions/osf.c
> +++ b/fs/partitions/osf.c
> @@ -10,10 +10,13 @@
>  #include "check.h"
>  #include "osf.h"
>  
> +#define MAX_OSF_PARTITIONS 8
> +
>  int osf_partition(struct parsed_partitions *state)
>  {
>  	int i;
>  	int slot = 1;
> +	unsigned int npartitions;
>  	Sector sect;
>  	unsigned char *data;
>  	struct disklabel {
> @@ -45,7 +48,7 @@ int osf_partition(struct parsed_partitions *state)
>  			u8  p_fstype;
>  			u8  p_frag;
>  			__le16 p_cpg;
> -		} d_partitions[8];
> +		} d_partitions[MAX_OSF_PARTITIONS];
>  	} * label;
>  	struct d_partition * partition;
>  
> @@ -63,7 +66,12 @@ int osf_partition(struct parsed_partitions *state)
>  		put_dev_sector(sect);
>  		return 0;
>  	}
> -	for (i = 0 ; i < le16_to_cpu(label->d_npartitions); i++, partition++) {
> +	npartitions = le16_to_cpu(label->d_npartitions);
> +	if (npartitions > MAX_OSF_PARTITIONS) {
> +		put_dev_sector(sect);
> +		return 0;
> +	}
> +	for (i = 0 ; i < npartitions; i++, partition++) {
>  		if (slot == state->limit)
>  		        break;
>  		if (le32_to_cpu(partition->p_size))
> -- 
> 1.7.4.1
> 
>
Brad Figg - June 14, 2011, 7:28 a.m.
On 06/13/2011 03:03 PM, Andy Whitcroft wrote:
> From: Timo Warns<Warns@pre-sense.de>
>
> The kernel automatically evaluates partition tables of storage devices.
> The code for evaluating OSF partitions contains a bug that leaks data
> from kernel heap memory to userspace for certain corrupted OSF
> partitions.
>
> In more detail:
>
>    for (i = 0 ; i<  le16_to_cpu(label->d_npartitions); i++, partition++) {
>
> iterates from 0 to d_npartitions - 1, where d_npartitions is read from
> the partition table without validation and partition is a pointer to an
> array of at most 8 d_partitions.
>
> Add the proper and obvious validation.
>
> Signed-off-by: Timo Warns<warns@pre-sense.de>
> Cc: stable@kernel.org
> [ Changed the patch trivially to not repeat the whole le16_to_cpu()
>    thing, and to use an explicit constant for the magic value '8' ]
> Signed-off-by: Linus Torvalds<torvalds@linux-foundation.org>
>
> (cherry picked from commit 1eafbfeb7bdf59cfe173304c76188f3fd5f1fd05)
> CVE-2011-1163
> BugLink: http://bugs.launchpad.net/bugs/796606
> Signed-off-by: Andy Whitcroft<apw@canonical.com>
> ---
>   fs/partitions/osf.c |   12 ++++++++++--
>   1 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/fs/partitions/osf.c b/fs/partitions/osf.c
> index fc22b85..5b49d40 100644
> --- a/fs/partitions/osf.c
> +++ b/fs/partitions/osf.c
> @@ -10,10 +10,13 @@
>   #include "check.h"
>   #include "osf.h"
>
> +#define MAX_OSF_PARTITIONS 8
> +
>   int osf_partition(struct parsed_partitions *state)
>   {
>   	int i;
>   	int slot = 1;
> +	unsigned int npartitions;
>   	Sector sect;
>   	unsigned char *data;
>   	struct disklabel {
> @@ -45,7 +48,7 @@ int osf_partition(struct parsed_partitions *state)
>   			u8  p_fstype;
>   			u8  p_frag;
>   			__le16 p_cpg;
> -		} d_partitions[8];
> +		} d_partitions[MAX_OSF_PARTITIONS];
>   	} * label;
>   	struct d_partition * partition;
>
> @@ -63,7 +66,12 @@ int osf_partition(struct parsed_partitions *state)
>   		put_dev_sector(sect);
>   		return 0;
>   	}
> -	for (i = 0 ; i<  le16_to_cpu(label->d_npartitions); i++, partition++) {
> +	npartitions = le16_to_cpu(label->d_npartitions);
> +	if (npartitions>  MAX_OSF_PARTITIONS) {
> +		put_dev_sector(sect);
> +		return 0;
> +	}
> +	for (i = 0 ; i<  npartitions; i++, partition++) {
>   		if (slot == state->limit)
>   		        break;
>   		if (le32_to_cpu(partition->p_size))

Acked-by: Brad Figg <brad.figg@canonical.com>

Patch

diff --git a/fs/partitions/osf.c b/fs/partitions/osf.c
index fc22b85..5b49d40 100644
--- a/fs/partitions/osf.c
+++ b/fs/partitions/osf.c
@@ -10,10 +10,13 @@ 
 #include "check.h"
 #include "osf.h"
 
+#define MAX_OSF_PARTITIONS 8
+
 int osf_partition(struct parsed_partitions *state)
 {
 	int i;
 	int slot = 1;
+	unsigned int npartitions;
 	Sector sect;
 	unsigned char *data;
 	struct disklabel {
@@ -45,7 +48,7 @@  int osf_partition(struct parsed_partitions *state)
 			u8  p_fstype;
 			u8  p_frag;
 			__le16 p_cpg;
-		} d_partitions[8];
+		} d_partitions[MAX_OSF_PARTITIONS];
 	} * label;
 	struct d_partition * partition;
 
@@ -63,7 +66,12 @@  int osf_partition(struct parsed_partitions *state)
 		put_dev_sector(sect);
 		return 0;
 	}
-	for (i = 0 ; i < le16_to_cpu(label->d_npartitions); i++, partition++) {
+	npartitions = le16_to_cpu(label->d_npartitions);
+	if (npartitions > MAX_OSF_PARTITIONS) {
+		put_dev_sector(sect);
+		return 0;
+	}
+	for (i = 0 ; i < npartitions; i++, partition++) {
 		if (slot == state->limit)
 		        break;
 		if (le32_to_cpu(partition->p_size))