From b03a7771c81a0d5f026250c8cd4091d9ee767fdc Mon Sep 17 00:00:00 2001 From: "Stephen M. Cameron" Date: Thu, 6 Jan 2011 14:47:48 -0600 Subject: [PATCH] [SCSI] hpsa: defend against zero sized buffers in passthru ioctls Signed-off-by: Stephen M. Cameron Signed-off-by: James Bottomley --- drivers/scsi/hpsa.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index 12deffccb8da..e4b5f3cda82e 100644 --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -2433,15 +2433,17 @@ static int hpsa_passthru_ioctl(struct ctlr_info *h, void __user *argp) buff = kmalloc(iocommand.buf_size, GFP_KERNEL); if (buff == NULL) return -EFAULT; - } - if (iocommand.Request.Type.Direction == XFER_WRITE) { - /* Copy the data into the buffer we created */ - if (copy_from_user(buff, iocommand.buf, iocommand.buf_size)) { - kfree(buff); - return -EFAULT; + if (iocommand.Request.Type.Direction == XFER_WRITE) { + /* Copy the data into the buffer we created */ + if (copy_from_user(buff, iocommand.buf, + iocommand.buf_size)) { + kfree(buff); + return -EFAULT; + } + } else { + memset(buff, 0, iocommand.buf_size); } - } else - memset(buff, 0, iocommand.buf_size); + } c = cmd_special_alloc(h); if (c == NULL) { kfree(buff); @@ -2487,8 +2489,8 @@ static int hpsa_passthru_ioctl(struct ctlr_info *h, void __user *argp) cmd_special_free(h, c); return -EFAULT; } - - if (iocommand.Request.Type.Direction == XFER_READ) { + if (iocommand.Request.Type.Direction == XFER_READ && + iocommand.buf_size > 0) { /* Copy the data out of the buffer we created */ if (copy_to_user(iocommand.buf, buff, iocommand.buf_size)) { kfree(buff); @@ -2581,14 +2583,7 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp) } c->cmd_type = CMD_IOCTL_PEND; c->Header.ReplyQueue = 0; - - if (ioc->buf_size > 0) { - c->Header.SGList = sg_used; - c->Header.SGTotal = sg_used; - } else { - c->Header.SGList = 0; - c->Header.SGTotal = 0; - } + c->Header.SGList = c->Header.SGTotal = sg_used; memcpy(&c->Header.LUN, &ioc->LUN_info, sizeof(c->Header.LUN)); c->Header.Tag.lower = c->busaddr; memcpy(&c->Request, &ioc->Request, sizeof(c->Request)); @@ -2605,7 +2600,8 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp) } } hpsa_scsi_do_simple_cmd_core(h, c); - hpsa_pci_unmap(h->pdev, c, sg_used, PCI_DMA_BIDIRECTIONAL); + if (sg_used) + hpsa_pci_unmap(h->pdev, c, sg_used, PCI_DMA_BIDIRECTIONAL); check_ioctl_unit_attention(h, c); /* Copy the error information out */ memcpy(&ioc->error_info, c->err_info, sizeof(ioc->error_info)); @@ -2614,7 +2610,7 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h, void __user *argp) status = -EFAULT; goto cleanup1; } - if (ioc->Request.Type.Direction == XFER_READ) { + if (ioc->Request.Type.Direction == XFER_READ && ioc->buf_size > 0) { /* Copy the data out of the buffer we created */ BYTE __user *ptr = ioc->buf; for (i = 0; i < sg_used; i++) {