diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index a27167942a9285d8d842049cdf629cd3152ad77a..163fd853a15f04090c120cdb1c69498852dce8af 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -81,7 +81,6 @@ struct rbd_image_header { __u8 crypt_type; __u8 comp_type; struct ceph_snap_context *snapc; - u64 snap_names_len; u32 total_snaps; char *snap_names; @@ -534,12 +533,21 @@ static int rbd_header_from_disk(struct rbd_image_header *header, header->object_prefix[len] = '\0'; if (snap_count) { - header->snap_names_len = le64_to_cpu(ondisk->snap_names_len); - BUG_ON(header->snap_names_len > (u64) SIZE_MAX); - header->snap_names = kmalloc(header->snap_names_len, - GFP_KERNEL); + u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len); + + if (snap_names_len > (u64) SIZE_MAX) + return -EIO; + header->snap_names = kmalloc(snap_names_len, GFP_KERNEL); if (!header->snap_names) goto out_err; + /* + * Note that rbd_dev_v1_header_read() guarantees + * the ondisk buffer we're working with has + * snap_names_len bytes beyond the end of the + * snapshot id array, this memcpy() is safe. + */ + memcpy(header->snap_names, &ondisk->snaps[snap_count], + snap_names_len); size = snap_count * sizeof (*header->snap_sizes); header->snap_sizes = kmalloc(size, GFP_KERNEL); @@ -547,7 +555,6 @@ static int rbd_header_from_disk(struct rbd_image_header *header, goto out_err; } else { WARN_ON(ondisk->snap_names_len); - header->snap_names_len = 0; header->snap_names = NULL; header->snap_sizes = NULL; } @@ -579,10 +586,6 @@ static int rbd_header_from_disk(struct rbd_image_header *header, header->snap_sizes[i] = le64_to_cpu(ondisk->snaps[i].image_size); } - - /* copy snapshot names */ - memcpy(header->snap_names, &ondisk->snaps[snap_count], - header->snap_names_len); } return 0; @@ -592,7 +595,6 @@ static int rbd_header_from_disk(struct rbd_image_header *header, header->snap_sizes = NULL; kfree(header->snap_names); header->snap_names = NULL; - header->snap_names_len = 0; kfree(header->object_prefix); header->object_prefix = NULL; @@ -660,7 +662,6 @@ static void rbd_header_free(struct rbd_image_header *header) header->snap_sizes = NULL; kfree(header->snap_names); header->snap_names = NULL; - header->snap_names_len = 0; ceph_put_snap_context(header->snapc); header->snapc = NULL; } @@ -1800,7 +1801,6 @@ static int __rbd_refresh_header(struct rbd_device *rbd_dev, u64 *hver) rbd_dev->header.total_snaps = h.total_snaps; rbd_dev->header.snapc = h.snapc; rbd_dev->header.snap_names = h.snap_names; - rbd_dev->header.snap_names_len = h.snap_names_len; rbd_dev->header.snap_sizes = h.snap_sizes; /* Free the extra copy of the object prefix */ WARN_ON(strcmp(rbd_dev->header.object_prefix, h.object_prefix));