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Fix corrupted OSF partition table parsing 

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>
This commit is contained in:
Timo Warns 2011-03-14 14:59:33 +01:00 committed by Linus Torvalds
parent 2fbfac4e05
commit 1eafbfeb7b
1 changed files with 10 additions and 2 deletions
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12
fs/partitions/osf.c
View File

@ -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))