[PATCH RESEND] scsi: hpsa: Replace kmalloc + copy_from_user with memdup_user

[PATCH RESEND] scsi: hpsa: Replace kmalloc + copy_from_user with memdup_user

[Thorsten Blum]

Replace kmalloc() followed by copy_from_user() with memdup_user() to
improve and simplify hpsa_passthru_ioctl().

Since memdup_user() already allocates memory, use kzalloc() in the else
branch instead of manually zeroing 'buff' using memset(0).

Return early if an error occurs and remove the 'out_kfree' label.

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 drivers/scsi/hpsa.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index c73a71ac3c29..55448238d8ed 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -6407,18 +6407,14 @@ static int hpsa_passthru_ioctl(struct ctlr_info *h,
 		return -EINVAL;
 	}
 	if (iocommand->buf_size > 0) {
-		buff = kmalloc(iocommand->buf_size, GFP_KERNEL);
-		if (buff == NULL)
-			return -ENOMEM;
 		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)) {
-				rc = -EFAULT;
-				goto out_kfree;
-			}
+			buff = memdup_user(iocommand->buf, iocommand->buf_size);
+			if (IS_ERR(buff))
+				return PTR_ERR(buff);
 		} else {
-			memset(buff, 0, iocommand->buf_size);
+			buff = kzalloc(iocommand->buf_size, GFP_KERNEL);
+			if (!buff)
+				return -ENOMEM;
 		}
 	}
 	c = cmd_alloc(h);
@@ -6478,7 +6474,6 @@ static int hpsa_passthru_ioctl(struct ctlr_info *h,
 	}
 out:
 	cmd_free(h, c);
-out_kfree:
 	kfree(buff);
 	return rc;
 }
-- 
2.51.0

Re: [PATCH RESEND] scsi: hpsa: Replace kmalloc + copy_from_user with memdup_user

[Don.Brace]

________________________________________
From: Thorsten Blum <thorsten.blum@linux.dev>
Sent: Tuesday, September 23, 2025 12:15 PM
To: Don Brace - C33706 <Don.Brace@microchip.com>; James E.J. Bottomley <James.Bottomley@HansenPartnership.com>; Martin K. Petersen <martin.petersen@oracle.com>
Cc: Thorsten Blum <thorsten.blum@linux.dev>; storagedev <storagedev@microchip.com>; linux-scsi@vger.kernel.org <linux-scsi@vger.kernel.org>; linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>
Subject: [PATCH RESEND] scsi: hpsa: Replace kmalloc + copy_from_user with memdup_user
 
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Replace kmalloc() followed by copy_from_user() with memdup_user() to
improve and simplify hpsa_passthru_ioctl().

Since memdup_user() already allocates memory, use kzalloc() in the else
branch instead of manually zeroing 'buff' using memset(0).

Return early if an error occurs and remove the 'out_kfree' label.

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---

Acked-by: Don Brace <don.brace@microchip.com>

Thanks for your patch.

We do not normally make changes to this driver as it is in maintenance mode.

Re: [PATCH RESEND] scsi: hpsa: Replace kmalloc + copy_from_user with memdup_user

[Thorsten Blum]

Hi Don,

On 23. Sep 2025, at 21:40, Don.Brace@microchip.com wrote:
> ...
> Thanks for your patch.
> 
> We do not normally make changes to this driver as it is in maintenance mode.

Is there a general way to check if a driver is in maintenance mode?

Did you get a chance to look at my other patch [1] yet, which fixes a
potential memory leak in this driver? That's probably more important
than the refactorings.

Thanks,
Thorsten

[1] https://lore.kernel.org/lkml/20250919092637.721325-1-thorsten.blum@linux.dev/

Re: [PATCH RESEND] scsi: hpsa: Replace kmalloc + copy_from_user with memdup_user

[Martin K. Petersen]

Thorsten,

> Replace kmalloc() followed by copy_from_user() with memdup_user() to
> improve and simplify hpsa_passthru_ioctl().
>
> Since memdup_user() already allocates memory, use kzalloc() in the
> else branch instead of manually zeroing 'buff' using memset(0).
>
> Return early if an error occurs and remove the 'out_kfree' label.

Applied to 6.18/scsi-staging, thanks!

-- 
Martin K. Petersen