diff options
author | aliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162> | 2009-01-28 21:58:22 +0000 |
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committer | aliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162> | 2009-01-28 21:58:22 +0000 |
commit | e035b43d7c98b1509420d41b017abcdac0de0442 (patch) | |
tree | 2dccc84bb2394e3b5d5b56474abea2ab24c72a64 /hw/scsi-disk.c | |
parent | baa8c602295b1d33844503ce0a172b85f84646d3 (diff) |
fix signed/unsigned overflows in SCSI disk (Rik van Riel)
Sector numbers can overflow on a virtual scsi disk of over 1TB
in size. Qemu's bdrv_read expects an int64_t, so fix the overflow
by going to that data type.
On large disks, we clip the capacity to 2TB instead of returning
"capacity modulo 2TB".
Turn sector_count into an unsigned to prevent a signed/unsigned
overflow with SCSI transfers larger than 2TB. We're unlikely to
ever hit this bug, but fixing it is just one line.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6467 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'hw/scsi-disk.c')
-rw-r--r-- | hw/scsi-disk.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c index 2a571a0f16..89b44c31b7 100644 --- a/hw/scsi-disk.c +++ b/hw/scsi-disk.c @@ -47,11 +47,11 @@ do { fprintf(stderr, "scsi-disk: " fmt , ##args); } while (0) typedef struct SCSIRequest { SCSIDeviceState *dev; uint32_t tag; - /* ??? We should probably keep track of whether the data trasfer is + /* ??? We should probably keep track of whether the data transfer is a read or a write. Currently we rely on the host getting it right. */ /* Both sector and sector_count are in terms of qemu 512 byte blocks. */ - int sector; - int sector_count; + uint64_t sector; + uint32_t sector_count; /* The amounnt of data in the buffer. */ int buf_len; uint8_t *dma_buf; @@ -731,6 +731,9 @@ static int32_t scsi_send_command(SCSIDevice *d, uint32_t tag, /* Returned value is the address of the last sector. */ if (nb_sectors) { nb_sectors--; + /* Clip to 2TB, instead of returning capacity modulo 2TB. */ + if (nb_sectors > UINT32_MAX) + nb_sectors = UINT32_MAX; outbuf[0] = (nb_sectors >> 24) & 0xff; outbuf[1] = (nb_sectors >> 16) & 0xff; outbuf[2] = (nb_sectors >> 8) & 0xff; |