block: validate interval_exp integrity limit

Various code assumes that the integrity interval is at least 1 sector
and evenly divides the logical block size. Add these checks to
blk_validate_integrity_limits(). This guards against block drivers that
report invalid interval_exp values.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-settings.c b/block/blk-settings.c
index d138abc973bba0a56ca8a994322069205ae5af95..a9e65dc090dae886c2ef4e45e3d9c682f663ce50 100644 (file)
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -193,8 +193,13 @@ static int blk_validate_integrity_limits(struct queue_limits *lim)
                break;
        }
 
-       if (!bi->interval_exp)
+       if (!bi->interval_exp) {
                bi->interval_exp = ilog2(lim->logical_block_size);
+       } else if (bi->interval_exp < SECTOR_SHIFT ||
+                  bi->interval_exp > ilog2(lim->logical_block_size)) {
+               pr_warn("invalid interval_exp %u\n", bi->interval_exp);
+               return -EINVAL;
+       }
 
        /*
         * The PI generation / validation helpers do not expect intervals to