diff mbox series

[v2,8/9] libata-scsi: Move sense buffers onto stack

Message ID 20180731195155.46664-9-keescook@chromium.org (mailing list archive)
State Not Applicable
Headers show
Series block: Consolidate scsi sense buffer usage | expand

Commit Message

Kees Cook July 31, 2018, 7:51 p.m. UTC 
To support future compile-time sizeof() checks that will be able to
validate the length of sense buffers, this removes the only dynamically
allocated sense buffers in the tree by putting the 96 byte sense buffers
on the stack.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/ata/libata-scsi.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

Comments

Christoph Hellwig Aug. 1, 2018, 8:24 a.m. UTC | #1 
On Tue, Jul 31, 2018 at 12:51:53PM -0700, Kees Cook wrote:
> To support future compile-time sizeof() checks that will be able to
> validate the length of sense buffers, this removes the only dynamically
> allocated sense buffers in the tree by putting the 96 byte sense buffers
> on the stack.
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
Tejun Heo Aug. 1, 2018, 3:45 p.m. UTC | #2 
On Tue, Jul 31, 2018 at 12:51:53PM -0700, Kees Cook wrote:
> To support future compile-time sizeof() checks that will be able to
> validate the length of sense buffers, this removes the only dynamically
> allocated sense buffers in the tree by putting the 96 byte sense buffers
> on the stack.

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.
diff mbox series

Patch

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 89a9d4a2efc8..3a43d3a1ce2d 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -597,8 +597,9 @@  static int ata_get_identity(struct ata_port *ap, struct scsi_device *sdev,
 int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg)
 {
 	int rc = 0;
+	u8 sensebuf[SCSI_SENSE_BUFFERSIZE];
 	u8 scsi_cmd[MAX_COMMAND_SIZE];
-	u8 args[4], *argbuf = NULL, *sensebuf = NULL;
+	u8 args[4], *argbuf = NULL;
 	int argsize = 0;
 	enum dma_data_direction data_dir;
 	struct scsi_sense_hdr sshdr;
@@ -610,10 +611,7 @@  int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg)
 	if (copy_from_user(args, arg, sizeof(args)))
 		return -EFAULT;
 
-	sensebuf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
-	if (!sensebuf)
-		return -ENOMEM;
-
+	memset(sensebuf, 0, sizeof(sensebuf));
 	memset(scsi_cmd, 0, sizeof(scsi_cmd));
 
 	if (args[3]) {
@@ -685,7 +683,6 @@  int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg)
 	 && copy_to_user(arg + sizeof(args), argbuf, argsize))
 		rc = -EFAULT;
 error:
-	kfree(sensebuf);
 	kfree(argbuf);
 	return rc;
 }
@@ -704,8 +701,9 @@  int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg)
 int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg)
 {
 	int rc = 0;
+	u8 sensebuf[SCSI_SENSE_BUFFERSIZE];
 	u8 scsi_cmd[MAX_COMMAND_SIZE];
-	u8 args[7], *sensebuf = NULL;
+	u8 args[7];
 	struct scsi_sense_hdr sshdr;
 	int cmd_result;
 
@@ -715,10 +713,7 @@  int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg)
 	if (copy_from_user(args, arg, sizeof(args)))
 		return -EFAULT;
 
-	sensebuf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
-	if (!sensebuf)
-		return -ENOMEM;
-
+	memset(sensebuf, 0, sizeof(sensebuf));
 	memset(scsi_cmd, 0, sizeof(scsi_cmd));
 	scsi_cmd[0]  = ATA_16;
 	scsi_cmd[1]  = (3 << 1); /* Non-data */
@@ -769,7 +764,6 @@  int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg)
 	}
 
  error:
-	kfree(sensebuf);
 	return rc;
 }