Kees Cook <keescook@xxxxxxxxxxxx> writes:
> If md->signature == MAC_DRIVER_MAGIC and md->block_size == 1023, a single
> 512 byte sector would be read (secsize / 512). However the partition
> structure would be located past the end of the buffer (secsize % 512).
Do we even want to support non-power-of-two block sizes?
-Jeff
>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> There doesn't seem to be a mac partition maintainer...
> ---
> block/partitions/mac.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/block/partitions/mac.c b/block/partitions/mac.c
> index c2c48ec64b27..621317ac4d59 100644
> --- a/block/partitions/mac.c
> +++ b/block/partitions/mac.c
> @@ -32,7 +32,7 @@ int mac_partition(struct parsed_partitions *state)
> Sector sect;
> unsigned char *data;
> int slot, blocks_in_map;
> - unsigned secsize;
> + unsigned secsize, datasize, partoffset;
> #ifdef CONFIG_PPC_PMAC
> int found_root = 0;
> int found_root_goodness = 0;
> @@ -50,10 +50,14 @@ int mac_partition(struct parsed_partitions *state)
> }
> secsize = be16_to_cpu(md->block_size);
> put_dev_sector(sect);
> - data = read_part_sector(state, secsize/512, §);
> + datasize = round_down(secsize, 512);
> + data = read_part_sector(state, datasize / 512, §);
> if (!data)
> return -1;
> - part = (struct mac_partition *) (data + secsize%512);
> + partoffset = secsize % 512;
> + if (partoffset + sizeof(*part) > datasize)
> + return -1;
> + part = (struct mac_partition *) (data + partoffset);
> if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
> put_dev_sector(sect);
> return 0; /* not a MacOS disk */
> --
> 1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
