[PATCH] scsi: megaraid: Avoid mismatched storage type sizes

From: Kees Cook
Date: Fri Dec 03 2021 - 04:14:30 EST


Remove needless use of mbox_t, replacing with just struct
mbox_out. Silences compiler warnings under a -Warray-bounds build:

drivers/scsi/megaraid.c: In function 'megaraid_probe_one':
drivers/scsi/megaraid.c:3615:30: error: array subscript 'mbox_t[0]' is partly outside array bounds of 'unsigned char[15]' [-Werror=array-bounds]
3615 | mbox->m_out.xferaddr = (u32)adapter->buf_dma_handle;
| ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/megaraid.c:3599:23: note: while referencing 'raw_mbox'
3599 | unsigned char raw_mbox[sizeof(struct mbox_out)];
| ^~~~~~~~

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
drivers/scsi/megaraid.c | 84 +++++++++++++++++------------------------
1 file changed, 34 insertions(+), 50 deletions(-)

diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c
index 0d31d7a5e335..bf987f3a7f3f 100644
--- a/drivers/scsi/megaraid.c
+++ b/drivers/scsi/megaraid.c
@@ -192,23 +192,21 @@ mega_query_adapter(adapter_t *adapter)
{
dma_addr_t prod_info_dma_handle;
mega_inquiry3 *inquiry3;
- u8 raw_mbox[sizeof(struct mbox_out)];
- mbox_t *mbox;
+ struct mbox_out mbox;
+ u8 *raw_mbox = (u8 *)&mbox;
int retval;

/* Initialize adapter inquiry mailbox */

- mbox = (mbox_t *)raw_mbox;
-
memset((void *)adapter->mega_buffer, 0, MEGA_BUFFER_SIZE);
- memset(&mbox->m_out, 0, sizeof(raw_mbox));
+ memset(&mbox, 0, sizeof(mbox));

/*
* Try to issue Inquiry3 command
* if not succeeded, then issue MEGA_MBOXCMD_ADAPTERINQ command and
* update enquiry3 structure
*/
- mbox->m_out.xferaddr = (u32)adapter->buf_dma_handle;
+ mbox.xferaddr = (u32)adapter->buf_dma_handle;

inquiry3 = (mega_inquiry3 *)adapter->mega_buffer;

@@ -232,10 +230,10 @@ mega_query_adapter(adapter_t *adapter)

inq = &ext_inq->raid_inq;

- mbox->m_out.xferaddr = (u32)dma_handle;
+ mbox.xferaddr = (u32)dma_handle;

/*issue old 0x04 command to adapter */
- mbox->m_out.cmd = MEGA_MBOXCMD_ADPEXTINQ;
+ mbox.cmd = MEGA_MBOXCMD_ADPEXTINQ;

issue_scb_block(adapter, raw_mbox);

@@ -262,7 +260,7 @@ mega_query_adapter(adapter_t *adapter)
sizeof(mega_product_info),
DMA_FROM_DEVICE);

- mbox->m_out.xferaddr = prod_info_dma_handle;
+ mbox.xferaddr = prod_info_dma_handle;

raw_mbox[0] = FC_NEW_CONFIG; /* i.e. mbox->cmd=0xA1 */
raw_mbox[2] = NC_SUBOP_PRODUCT_INFO; /* i.e. 0x0E */
@@ -3569,16 +3567,14 @@ mega_n_to_m(void __user *arg, megacmd_t *mc)
static int
mega_is_bios_enabled(adapter_t *adapter)
{
- unsigned char raw_mbox[sizeof(struct mbox_out)];
- mbox_t *mbox;
-
- mbox = (mbox_t *)raw_mbox;
+ struct mbox_out mbox;
+ unsigned char *raw_mbox = (u8 *)&mbox;

- memset(&mbox->m_out, 0, sizeof(raw_mbox));
+ memset(&mbox, 0, sizeof(mbox));

memset((void *)adapter->mega_buffer, 0, MEGA_BUFFER_SIZE);

- mbox->m_out.xferaddr = (u32)adapter->buf_dma_handle;
+ mbox.xferaddr = (u32)adapter->buf_dma_handle;

raw_mbox[0] = IS_BIOS_ENABLED;
raw_mbox[2] = GET_BIOS;
@@ -3600,13 +3596,11 @@ mega_is_bios_enabled(adapter_t *adapter)
static void
mega_enum_raid_scsi(adapter_t *adapter)
{
- unsigned char raw_mbox[sizeof(struct mbox_out)];
- mbox_t *mbox;
+ struct mbox_out mbox;
+ unsigned char *raw_mbox = (u8 *)&mbox;
int i;

- mbox = (mbox_t *)raw_mbox;
-
- memset(&mbox->m_out, 0, sizeof(raw_mbox));
+ memset(&mbox, 0, sizeof(mbox));

/*
* issue command to find out what channels are raid/scsi
@@ -3616,7 +3610,7 @@ mega_enum_raid_scsi(adapter_t *adapter)

memset((void *)adapter->mega_buffer, 0, MEGA_BUFFER_SIZE);

- mbox->m_out.xferaddr = (u32)adapter->buf_dma_handle;
+ mbox.xferaddr = (u32)adapter->buf_dma_handle;

/*
* Non-ROMB firmware fail this command, so all channels
@@ -3655,23 +3649,21 @@ static void
mega_get_boot_drv(adapter_t *adapter)
{
struct private_bios_data *prv_bios_data;
- unsigned char raw_mbox[sizeof(struct mbox_out)];
- mbox_t *mbox;
+ struct mbox_out mbox;
+ unsigned char *raw_mbox = (u8 *)&mbox;
u16 cksum = 0;
u8 *cksum_p;
u8 boot_pdrv;
int i;

- mbox = (mbox_t *)raw_mbox;
-
- memset(&mbox->m_out, 0, sizeof(raw_mbox));
+ memset(&mbox, 0, sizeof(mbox));

raw_mbox[0] = BIOS_PVT_DATA;
raw_mbox[2] = GET_BIOS_PVT_DATA;

memset((void *)adapter->mega_buffer, 0, MEGA_BUFFER_SIZE);

- mbox->m_out.xferaddr = (u32)adapter->buf_dma_handle;
+ mbox.xferaddr = (u32)adapter->buf_dma_handle;

adapter->boot_ldrv_enabled = 0;
adapter->boot_ldrv = 0;
@@ -3721,13 +3713,11 @@ mega_get_boot_drv(adapter_t *adapter)
static int
mega_support_random_del(adapter_t *adapter)
{
- unsigned char raw_mbox[sizeof(struct mbox_out)];
- mbox_t *mbox;
+ struct mbox_out mbox;
+ unsigned char *raw_mbox = (u8 *)&mbox;
int rval;

- mbox = (mbox_t *)raw_mbox;
-
- memset(&mbox->m_out, 0, sizeof(raw_mbox));
+ memset(&mbox, 0, sizeof(mbox));

/*
* issue command
@@ -3750,13 +3740,11 @@ mega_support_random_del(adapter_t *adapter)
static int
mega_support_ext_cdb(adapter_t *adapter)
{
- unsigned char raw_mbox[sizeof(struct mbox_out)];
- mbox_t *mbox;
+ struct mbox_out mbox;
+ unsigned char *raw_mbox = (u8 *)&mbox;
int rval;

- mbox = (mbox_t *)raw_mbox;
-
- memset(&mbox->m_out, 0, sizeof(raw_mbox));
+ memset(&mbox, 0, sizeof(mbox));
/*
* issue command to find out if controller supports extended CDBs.
*/
@@ -3865,16 +3853,14 @@ mega_do_del_logdrv(adapter_t *adapter, int logdrv)
static void
mega_get_max_sgl(adapter_t *adapter)
{
- unsigned char raw_mbox[sizeof(struct mbox_out)];
- mbox_t *mbox;
+ struct mbox_out mbox;
+ unsigned char *raw_mbox = (u8 *)&mbox;

- mbox = (mbox_t *)raw_mbox;
-
- memset(mbox, 0, sizeof(raw_mbox));
+ memset(&mbox, 0, sizeof(mbox));

memset((void *)adapter->mega_buffer, 0, MEGA_BUFFER_SIZE);

- mbox->m_out.xferaddr = (u32)adapter->buf_dma_handle;
+ mbox.xferaddr = (u32)adapter->buf_dma_handle;

raw_mbox[0] = MAIN_MISC_OPCODE;
raw_mbox[2] = GET_MAX_SG_SUPPORT;
@@ -3888,7 +3874,7 @@ mega_get_max_sgl(adapter_t *adapter)
}
else {
adapter->sglen = *((char *)adapter->mega_buffer);
-
+
/*
* Make sure this is not more than the resources we are
* planning to allocate
@@ -3910,16 +3896,14 @@ mega_get_max_sgl(adapter_t *adapter)
static int
mega_support_cluster(adapter_t *adapter)
{
- unsigned char raw_mbox[sizeof(struct mbox_out)];
- mbox_t *mbox;
-
- mbox = (mbox_t *)raw_mbox;
+ struct mbox_out mbox;
+ unsigned char *raw_mbox = (u8 *)&mbox;

- memset(mbox, 0, sizeof(raw_mbox));
+ memset(&mbox, 0, sizeof(mbox));

memset((void *)adapter->mega_buffer, 0, MEGA_BUFFER_SIZE);

- mbox->m_out.xferaddr = (u32)adapter->buf_dma_handle;
+ mbox.xferaddr = (u32)adapter->buf_dma_handle;

/*
* Try to get the initiator id. This command will succeed iff the
--
2.30.2