Skip to contentSkip to conversation

scsi: hpsa: Make buff allocation type unsigned

PATCH Applied Kees Cook 2 participants 3 messages Sep 17 – Oct 6

Subsystems (2)
SCSI Hewlett-packard smart array RAID driver (hpsa)
lore
Share & tools
lore

Kees Cook

author
#0 lore raw

PATCH 1/1 scsi: hpsa: Make buff allocation type unsigned

From: Kees Cook <[email protected]>

In preparation for converting the kmalloc family of allocators to the type-aware kmalloc_obj family, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (The kmalloc family returns "void *", which can be implicitly cast to any pointer type.)

The assigned type is "unsigned char **", but the converted allocation type would be "char **", whose elements point to a character type of a different signedness, so the two pointer types are not compatible. Take the size from the assignment target instead. No change in allocation size results.

Build tested ARCH=x86_64 allmodconfig with GCC 16.2.0:
drivers/scsi/hpsa.o

Assisted-by LLM coccinelle
Signed-off-by Kees Cook <[email protected]>

---
Cc: Don Brace <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: "Martin K. Petersen" <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>

---
 drivers/scsi/hpsa.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/scsi/hpsa.c +1 -1
index 8edad1830abe..364cff7671e5 100644
@@ -6499,7 +6499,7 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h,
 		return -EINVAL;
 	if (ioc->buf_size > ioc->malloc_size * SG_ENTRIES_IN_CMD)
 		return -EINVAL;
-	buff = kcalloc(SG_ENTRIES_IN_CMD, sizeof(char *), GFP_KERNEL);
+	buff = kcalloc(SG_ENTRIES_IN_CMD, sizeof(*buff), GFP_KERNEL);
 	if (!buff) {
 		status = -ENOMEM;
 		goto cleanup1;
Signature · 1 line
2.34.1
maintainer Applied
#1 lore raw

Kees,

Quoted 5 lines

The assigned type is "unsigned char **", but the converted allocation type would be "char **", whose elements point to a character type of a different signedness, so the two pointer types are not compatible. Take the size from the assignment target instead. No change in allocation size results.

Applied to 7.4/scsi-staging, thanks!

Signature · 1 line
Martin K. Petersen
maintainer Applied
#2 lore raw
In reply to Kees Cook
Quoted 6 lines · Kees Cook

In preparation for converting the kmalloc family of allocators to the type-aware kmalloc_obj family, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (The kmalloc family returns "void *", which can be implicitly cast to any pointer type.)

Quoted 7 lines

The assigned type is "unsigned char **", but the converted allocation type would be "char **", whose elements point to a character type of a different signedness, so the two pointer types are not compatible. Take the size from the assignment target instead. No change in allocation size results.

[...]

Applied to 7.4/scsi-queue, thanks!

[1/1] scsi: hpsa: Make buff allocation type unsigned

      https://git.kernel.org/mkp/scsi/c/d0105247ca7e
Signature · 1 line
Martin K. Petersen