scsi: sym53c8xx_2: iterator underflow in sym_getsync()

BugLink: http://bugs.launchpad.net/bugs/1783418
[ Upstream commit e6f791d95313c85f3dd4a26141e28e50ae9aa0ae ]

We wanted to exit the loop with "div" set to zero, but instead, if we
don't hit the break then "div" is -1 when we finish the loop.  It leads
to an array underflow a few lines later.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/scsi/sym53c8xx_2/sym_hipd.c b/drivers/scsi/sym53c8xx_2/sym_hipd.c
index ca360daa6a253c7a9a0f4f29eaeaf5a49a1a8c98..378af306fda1748d8f587f466bb83fa34dbc9b5c 100644 (file)
--- a/drivers/scsi/sym53c8xx_2/sym_hipd.c
+++ b/drivers/scsi/sym53c8xx_2/sym_hipd.c
@@ -536,7 +536,7 @@ sym_getsync(struct sym_hcb *np, u_char dt, u_char sfac, u_char *divp, u_char *fa
         *  Look for the greatest clock divisor that allows an 
         *  input speed faster than the period.
         */
-       while (div-- > 0)
+       while (--div > 0)
                if (kpc >= (div_10M[div] << 2)) break;
 
        /*