From: James Bottomley <jejb@mulgrave.(none)>
Date: Fri, 28 Oct 2005 18:17:30 +0000 (-0500)
Subject: [SCSI] avoid overflows in disk size calculations
X-Git-Tag: v2.6.15-rc1~723^2~2^2~43
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7a691bd34130920bef4d118a3f555ebc48544a63;p=linux-2.6

[SCSI] avoid overflows in disk size calculations

Be more careful about doing the arithmetic in the non-LBD case.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
---

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 9a1dc0cea0..98da5c8057 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1253,14 +1253,13 @@ got_data:
 		 * Jacques Gelinas (Jacques@solucorp.qc.ca)
 		 */
 		int hard_sector = sector_size;
-		sector_t sz = sdkp->capacity * (hard_sector/256);
+		sector_t sz = (sdkp->capacity/2) * (hard_sector/256);
 		request_queue_t *queue = sdp->request_queue;
-		sector_t mb;
+		sector_t mb = sz;
 
 		blk_queue_hardsect_size(queue, hard_sector);
 		/* avoid 64-bit division on 32-bit platforms */
-		mb = sz >> 1;
-		sector_div(sz, 1250);
+		sector_div(sz, 625);
 		mb -= sz - 974;
 		sector_div(mb, 1950);