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authorPeng Fan <van.freenix@gmail.com>2015-09-11 21:41:47 +0800
committerBrian Norris <computersforpeace@gmail.com>2015-09-28 17:23:21 -0700
commit2ce401d56b36a7492b26646b94d1fe9194880a1a (patch)
tree2ab0c5b5254b72e488c51cba6b0730c2b9b4cef6 /drivers/mtd/mtd_blkdevs.c
parent7446076e818814d3237b20a96112b44bdb3f8576 (diff)
downloadlinux-2ce401d56b36a7492b26646b94d1fe9194880a1a.tar.bz2
mtd: blktrans: fix multiplication overflow
In drivers/mtd/mtd_blkdevs.c: 406 set_capacity(gd, (new->size * tr->blksize) >> 9); The type of new->size is unsigned long and the type of tr->blksize is int, the result of 'new->size * tr->blksize' may exceed ULONG_MAX on 32bit machines. I use nand chip MT29F32G08CBADBWP which is 4GB and the parameters passed to kernel is 'mtdparts=gpmi-nand:-(user)', the whole nand chip will be treated as a 4GB mtd partition. new->size is 0x800000 and tr->blksize is 0x200, 'new->size * tr->blksize' however is 0. This is what we do not want to see. Using type cast u64 to fix the multiplication overflow issue. Signed-off-by: Peng Fan <van.freenix@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'drivers/mtd/mtd_blkdevs.c')
-rw-r--r--drivers/mtd/mtd_blkdevs.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 44dc965a2f7c..cb47d79f4c21 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -399,7 +399,7 @@ int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
snprintf(gd->disk_name, sizeof(gd->disk_name),
"%s%d", tr->name, new->devnum);
- set_capacity(gd, (new->size * tr->blksize) >> 9);
+ set_capacity(gd, ((u64)new->size * tr->blksize) >> 9);
/* Create the request queue */
spin_lock_init(&new->queue_lock);