redonkable/remarkable-linux
redonkable/remarkable-linux
1
0
Fork 0
Code Releases Activity

[SCSI] scsi_debug: Fix 32-bit overflow in do_device_access causing memory corruption

Browse source 
If I create a scsi_debug device that is larger than 4GB, the multiplication of
(block * scsi_debug_sector_size) can produce a 64-bit value.  Unfortunately,
the compiler sees two 32-bit quantities and performs a 32-bit multiplication,
thus truncating the bits above 2^32.  This causes the wrong memory location to
be read or written.  Change block and rest to be unsigned long long.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This commit is contained in:
Darrick J. Wong 2011-01-31 18:47:54 -08:00 committed by James Bottomley
parent 044d78e1ac
commit a361cc0025
1 changed files with 1 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
drivers/scsi/scsi_debug.c
View file

@ -1671,7 +1671,7 @@ static int do_device_access(struct scsi_cmnd *scmd,
unsigned long long lba, unsigned int num, int write)
{
int ret;
unsigned int block, rest = 0;
unsigned long long block, rest = 0;
int (*func)(struct scsi_cmnd *, unsigned char *, int);
func = write ? fetch_to_dev_buffer : fill_from_dev_buffer;