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authorTimo Warns <Warns@pre-sense.de>2011-03-14 14:59:33 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-14 10:14:28 -0700
commit1eafbfeb7bdf59cfe173304c76188f3fd5f1fd05 (patch)
treeeae0a7cdf358b1b0396e9c3ec935d0e6be72bdb2
parent2fbfac4e053861925fa3fffcdc327649b09af54c (diff)
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>
-rw-r--r--fs/partitions/osf.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/partitions/osf.c b/fs/partitions/osf.c
index 48cec7cbca17..be03a0b08b47 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))