When brd_direct_access() is called on a partition-bdev it would access the wrong sector. And caller would then corrupt the device's data. This is a preliminary fix, Matthew Wilcox has a patch in his DAX patchset which will define a global wrapper to bdev->bd_disk->fops->direct_access that will do the proper checks and translations before calling a driver global member. (The way it is done at the rest of the block stack) CC: Matthew Wilcox <matthew.r.wilcox@xxxxxxxxx> Signed-off-by: Boaz Harrosh <boaz@xxxxxxxxxxxxx> --- drivers/block/brd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 92334f6..7506864 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -378,9 +378,10 @@ static int brd_direct_access(struct block_device *bdev, sector_t sector, if (!brd) return -ENODEV; + sector += get_start_sect(bdev); if (sector & (PAGE_SECTORS-1)) return -EINVAL; - if (sector + PAGE_SECTORS > get_capacity(bdev->bd_disk)) + if (unlikely(sector + PAGE_SECTORS > part_nr_sects_read(bdev->bd_part))) return -ERANGE; page = brd_insert_page(brd, sector); if (!page) -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
