From dd43bce420668dcde639c55bc792cedb1bb8c950 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 5 Sep 2012 17:46:18 +0200 Subject: [PATCH] scsi-disk: introduce check_lba_range Abstract the test for an out-of-range (starting block, block count) pair. Signed-off-by: Paolo Bonzini (cherry picked from commit 444bc908611ccaf4512dc37c33ac3b54d873a62b) Signed-off-by: Michael Roth --- hw/scsi-disk.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c index 1585683..3959603 100644 --- a/hw/scsi-disk.c +++ b/hw/scsi-disk.c @@ -1449,6 +1449,18 @@ invalid_field: return; } +static inline bool check_lba_range(SCSIDiskState *s, + uint64_t sector_num, uint32_t nb_sectors) +{ + /* + * The first line tests that no overflow happens when computing the last + * sector. The second line tests that the last accessed sector is in + * range. + */ + return (sector_num <= sector_num + nb_sectors && + sector_num + nb_sectors - 1 <= s->qdev.max_lba); +} + typedef struct UnmapCBData { SCSIDiskReq *r; uint8_t *inbuf; @@ -1473,8 +1485,7 @@ static void scsi_unmap_complete(void *opaque, int ret) if (data->count > 0 && !r->req.io_canceled) { sector_num = ldq_be_p(&data->inbuf[0]); nb_sectors = ldl_be_p(&data->inbuf[8]) & 0xffffffffULL; - if (sector_num > sector_num + nb_sectors || - sector_num + nb_sectors - 1 > s->qdev.max_lba) { + if (!check_lba_range(s, sector_num, nb_sectors)) { scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE)); goto done; } @@ -1802,8 +1813,7 @@ static int32_t scsi_disk_emulate_command(SCSIRequest *req, uint8_t *buf) scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED)); return 0; } - if (r->req.cmd.lba > r->req.cmd.lba + nb_sectors || - r->req.cmd.lba + nb_sectors - 1 > s->qdev.max_lba) { + if (!check_lba_range(s, r->req.cmd.lba, nb_sectors)) { goto illegal_lba; } @@ -1878,8 +1888,7 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf) if (r->req.cmd.buf[1] & 0xe0) { goto illegal_request; } - if (r->req.cmd.lba > r->req.cmd.lba + len || - r->req.cmd.lba + len - 1 > s->qdev.max_lba) { + if (!check_lba_range(s, r->req.cmd.lba, len)) { goto illegal_lba; } r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512); @@ -1907,8 +1916,7 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf) if (r->req.cmd.buf[1] & 0xe0) { goto illegal_request; } - if (r->req.cmd.lba > r->req.cmd.lba + len || - r->req.cmd.lba + len - 1 > s->qdev.max_lba) { + if (!check_lba_range(s, r->req.cmd.lba, len)) { goto illegal_lba; } r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512); -- 1.7.12.1