SG_GET_RESERVED_SIZE and SG_SET_RESERVED_SIZE ioctls access a reserved
buffer in bytes as int type. The value needs to be capped at the request
queue's max_sectors. But integer overflow is not correctly handled in
the calculation when converting max_sectors from sectors to bytes.
Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com>
Cc: Jens Axboe <ax...@kernel.dk>
Cc: "James E.J. Bottomley" <jbottom...@parallels.com>
Cc: Douglas Gilbert <dgilb...@interlog.com>
Cc: linux-scsi@vger.kernel.org
---
block/scsi_ioctl.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 2648797..6174bba 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -82,9 +82,18 @@ static int sg_set_timeout(struct request_queue *q, int
__user *p)
return err;
}
+static int max_sectors_bytes(struct request_queue *q)
+{
+ unsigned int max_sectors = queue_max_sectors(q);
+
+ max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
+
+ return max_sectors << 9;
+}
+
static int sg_get_reserved_size(struct request_queue *q, int __user *p)
{
- unsigned val = min(q->sg_reserved_size, queue_max_sectors(q) << 9);
+ int val = min_t(int, q->sg_reserved_size, max_sectors_bytes(q));
return put_user(val, p);
}
@@ -98,10 +107,8 @@ static int sg_set_reserved_size(struct request_queue *q,
int __user *p)
if (size < 0)
return -EINVAL;
- if (size > (queue_max_sectors(q) << 9))
- size = queue_max_sectors(q) << 9;
- q->sg_reserved_size = size;
+ q->sg_reserved_size = min(size, max_sectors_bytes(q));
return 0;
}
--
1.9.1
--
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