signed integer overflow happened in the following multiplication,
ext_cyl*(end_head+1)*end_sector = 0x41040*(0xff+1)*0x3f = 0xffffc000,
the overflow was caught by UBSAN and caused crash to the system,
use unsigned int instead of signed int to avoid integer overflow.
Signed-off-by: Xiaosen He <quic_xiaosenh@xxxxxxxxxxx>
Signed-off-by: Jian Zhou <quic_jianzhou@xxxxxxxxxxx>
---
drivers/scsi/scsicam.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/scsicam.c b/drivers/scsi/scsicam.c
index 910f4a7a3924..544a008ea422 100644
--- a/drivers/scsi/scsicam.c
+++ b/drivers/scsi/scsicam.c
@@ -126,13 +126,14 @@ int scsi_partsize(unsigned char *buf, unsigned long capacity,
unsigned int *cyls, unsigned int *hds, unsigned int *secs)
{
struct partition *p = (struct partition *)buf, *largest = NULL;
- int i, largest_cyl;
- int cyl, ext_cyl, end_head, end_cyl, end_sector;
+ int i;
+ unsigned int largest_cyl = UINT_MAX;
+ unsigned int cyl, ext_cyl, end_head, end_cyl, end_sector;
unsigned int logical_end, physical_end, ext_physical_end;
if (*(unsigned short *) (buf + 64) == 0xAA55) {
- for (largest_cyl = -1, i = 0; i < 4; ++i, ++p) {
+ for (i = 0; i < 4; ++i, ++p) {
if (!p->sys_ind)
continue;
#ifdef DEBUG
@@ -140,7 +141,7 @@ int scsi_partsize(unsigned char *buf, unsigned long capacity,
i);
#endif
cyl = p->cyl + ((p->sector & 0xc0) << 2);
- if (cyl > largest_cyl) {
+ if ((largest_cyl == UINT_MAX) || (cyl > largest_cyl)) {
largest_cyl = cyl;
largest = p;
}
--
2.34.1
