Re: [PATCH 6/6] scsi: message: fusion: struct _CONFIG_PAGE_IOC_4: Replace 1-element array with flexible array

From: Gustavo A. R. Silva
Date: Thu Jul 11 2024 - 14:20:07 EST




On 11/07/24 11:28, Kees Cook wrote:
Replace the deprecated[1] use of a 1-element array in
struct _CONFIG_PAGE_IOC_4 with a modern flexible array.

Additionally add __counted_by annotation since SEP is only ever accessed
after updating ACtiveSEP:

lsi/mpi_cnfg.h: IOC_4_SEP SEP[] __counted_by(ActiveSEP); /* 08h */
mptsas.c: ii = IOCPage4Ptr->ActiveSEP++;
mptsas.c: IOCPage4Ptr->SEP[ii].SEPTargetID = id;
mptsas.c: IOCPage4Ptr->SEP[ii].SEPBus = channel;

No binary differences are present after this conversion.

Link: https://github.com/KSPP/linux/issues/79 [1]
Signed-off-by: Kees Cook <kees@xxxxxxxxxx>

Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks!
--
Gustavo

---
Cc: Sathya Prakash <sathya.prakash@xxxxxxxxxxxx>
Cc: Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx>
Cc: Suganath Prabu Subramani <suganath-prabu.subramani@xxxxxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Cc: MPT-FusionLinux.pdl@xxxxxxxxxxxx
Cc: linux-scsi@xxxxxxxxxxxxxxx
Cc: linux-hardening@xxxxxxxxxxxxxxx
---
drivers/message/fusion/lsi/mpi_cnfg.h | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/drivers/message/fusion/lsi/mpi_cnfg.h b/drivers/message/fusion/lsi/mpi_cnfg.h
index bac49c162165..1167a16d8fb4 100644
--- a/drivers/message/fusion/lsi/mpi_cnfg.h
+++ b/drivers/message/fusion/lsi/mpi_cnfg.h
@@ -1077,21 +1077,13 @@ typedef struct _IOC_4_SEP
} IOC_4_SEP, MPI_POINTER PTR_IOC_4_SEP,
Ioc4Sep_t, MPI_POINTER pIoc4Sep_t;
-/*
- * Host code (drivers, BIOS, utilities, etc.) should leave this define set to
- * one and check Header.PageLength at runtime.
- */
-#ifndef MPI_IOC_PAGE_4_SEP_MAX
-#define MPI_IOC_PAGE_4_SEP_MAX (1)
-#endif
-
typedef struct _CONFIG_PAGE_IOC_4
{
CONFIG_PAGE_HEADER Header; /* 00h */
U8 ActiveSEP; /* 04h */
U8 MaxSEP; /* 05h */
U16 Reserved1; /* 06h */
- IOC_4_SEP SEP[MPI_IOC_PAGE_4_SEP_MAX]; /* 08h */
+ IOC_4_SEP SEP[] __counted_by(ActiveSEP); /* 08h */
} CONFIG_PAGE_IOC_4, MPI_POINTER PTR_CONFIG_PAGE_IOC_4,
IOCPage4_t, MPI_POINTER pIOCPage4_t;