[34-longterm 110/247] fs/partitions: Validate map_count in Mac partition tables

Paul Gortmaker
2011-06-23T18:13:21Z

From: Timo Warns <warns@pre-sense.de>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

commit fa7ea87a057958a8b7926c1a60a3ca6d696328ed upstream.

Validate number of blocks in map and remove redundant variable.

Signed-off-by: Timo Warns <warns@pre-sense.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
fs/partitions/mac.c | 17 +++++++++--------
1 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/fs/partitions/mac.c b/fs/partitions/mac.c
index d4a0fad..5765198 100644
--- a/fs/partitions/mac.c
+++ b/fs/partitions/mac.c
@@ -29,10 +29,9 @@ static inline void mac_fix_string(char *stg, int len)

int mac_partition(struct parsed_partitions *state, struct block_device *bdev)
{
- int slot = 1;
Sector sect;
unsigned char *data;
- int blk, blocks_in_map;
+ int slot, blocks_in_map;
unsigned secsize;
#ifdef CONFIG_PPC_PMAC
int found_root = 0;
@@ -59,10 +58,14 @@ int mac_partition(struct parsed_partitions *state, struct block_device *bdev)
put_dev_sector(sect);
return 0; /* not a MacOS disk */
}
- printk(" [mac]");
blocks_in_map = be32_to_cpu(part->map_count);
- for (blk = 1; blk <= blocks_in_map; ++blk) {
- int pos = blk * secsize;
+ if (blocks_in_map < 0 || blocks_in_map >= DISK_MAX_PARTS) {
+ put_dev_sector(sect);
+ return 0;
+ }
+ printk(" [mac]");
+ for (slot = 1; slot <= blocks_in_map; ++slot) {
+ int pos = slot * secsize;
put_dev_sector(sect);
data = read_dev_sector(bdev, pos/512, &sect);
if (!data)
@@ -113,13 +116,11 @@ int mac_partition(struct parsed_partitions *state, struct block_device *bdev)
}

if (goodness > found_root_goodness) {
- found_root = blk;
+ found_root = slot;
found_root_goodness = goodness;
}
}
#endif /* CONFIG_PPC_PMAC */
-
- ++slot;
}
#ifdef CONFIG_PPC_PMAC
if (found_root_goodness)
--
1.7.4.4