scsi: 3w-sas: Replace 1-element arrays with flexible array members

One-element arrays (and multi-element arrays being treated as dynamically
sized) are deprecated[1] and are being replaced with flexible array members
in support of the ongoing efforts to tighten the FORTIFY_SOURCE routines on
memcpy(), correctly instrument array indexing with UBSAN_BOUNDS, and to
globally enable -fstrict-flex-arrays=3.

Replace one-element arrays with flexible-array member in TW_Ioctl_Buf_Apache
and TW_Param_Apache, adjusting the explicit sizing calculations at the
same time.

This results in no differences in binary output.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

Cc: Adam Radford <aradford@gmail.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230105004757.never.017-kees@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index 3ebe661..f41c934 100644 (file)
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -690,7 +690,7 @@ static void twl_load_sgl(TW_Device_Extension *tw_dev, TW_Command_Full *full_comm
                newcommand->request_id__lunl =
                        cpu_to_le16(TW_REQ_LUN_IN(TW_LUN_OUT(newcommand->request_id__lunl), request_id));
                if (length) {
-                       newcommand->sg_list[0].address = TW_CPU_TO_SGL(dma_handle + sizeof(TW_Ioctl_Buf_Apache) - 1);
+                       newcommand->sg_list[0].address = TW_CPU_TO_SGL(dma_handle + sizeof(TW_Ioctl_Buf_Apache));
                        newcommand->sg_list[0].length = TW_CPU_TO_SGL(length);
                }
                newcommand->sgl_entries__lunh =
@@ -702,7 +702,7 @@ static void twl_load_sgl(TW_Device_Extension *tw_dev, TW_Command_Full *full_comm
                if (TW_SGL_OUT(oldcommand->opcode__sgloffset)) {
                        /* Load the sg list */
                        sgl = (TW_SG_Entry_ISO *)((u32 *)oldcommand+oldcommand->size - (sizeof(TW_SG_Entry_ISO)/4) + pae + (sizeof(dma_addr_t) > 4 ? 1 : 0));
-                       sgl->address = TW_CPU_TO_SGL(dma_handle + sizeof(TW_Ioctl_Buf_Apache) - 1);
+                       sgl->address = TW_CPU_TO_SGL(dma_handle + sizeof(TW_Ioctl_Buf_Apache));
                        sgl->length = TW_CPU_TO_SGL(length);
                        oldcommand->size += pae;
                        oldcommand->size += sizeof(dma_addr_t) > 4 ? 1 : 0;
@@ -748,7 +748,7 @@ static long twl_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long
        data_buffer_length_adjusted = (driver_command.buffer_length + 511) & ~511;
 
        /* Now allocate ioctl buf memory */
-       cpu_addr = dma_alloc_coherent(&tw_dev->tw_pci_dev->dev, data_buffer_length_adjusted+sizeof(TW_Ioctl_Buf_Apache) - 1, &dma_handle, GFP_KERNEL);
+       cpu_addr = dma_alloc_coherent(&tw_dev->tw_pci_dev->dev, data_buffer_length_adjusted + sizeof(TW_Ioctl_Buf_Apache), &dma_handle, GFP_KERNEL);
        if (!cpu_addr) {
                retval = -ENOMEM;
                goto out2;
@@ -757,7 +757,7 @@ static long twl_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long
        tw_ioctl = (TW_Ioctl_Buf_Apache *)cpu_addr;
 
        /* Now copy down the entire ioctl */
-       if (copy_from_user(tw_ioctl, argp, driver_command.buffer_length + sizeof(TW_Ioctl_Buf_Apache) - 1))
+       if (copy_from_user(tw_ioctl, argp, driver_command.buffer_length + sizeof(TW_Ioctl_Buf_Apache)))
                goto out3;
 
        /* See which ioctl we are doing */
@@ -815,11 +815,11 @@ static long twl_chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long
        }
 
        /* Now copy the entire response to userspace */
-       if (copy_to_user(argp, tw_ioctl, sizeof(TW_Ioctl_Buf_Apache) + driver_command.buffer_length - 1) == 0)
+       if (copy_to_user(argp, tw_ioctl, sizeof(TW_Ioctl_Buf_Apache) + driver_command.buffer_length) == 0)
                retval = 0;
 out3:
        /* Now free ioctl buf memory */
-       dma_free_coherent(&tw_dev->tw_pci_dev->dev, data_buffer_length_adjusted+sizeof(TW_Ioctl_Buf_Apache) - 1, cpu_addr, dma_handle);
+       dma_free_coherent(&tw_dev->tw_pci_dev->dev, data_buffer_length_adjusted + sizeof(TW_Ioctl_Buf_Apache), cpu_addr, dma_handle);
 out2:
        mutex_unlock(&tw_dev->ioctl_lock);
 out:

diff --git a/drivers/scsi/3w-sas.h b/drivers/scsi/3w-sas.h
index b050803..096dec2 100644 (file)
--- a/drivers/scsi/3w-sas.h
+++ b/drivers/scsi/3w-sas.h
@@ -335,7 +335,7 @@ typedef struct TAG_TW_Ioctl_Apache {
        TW_Ioctl_Driver_Command driver_command;
        char padding[488];
        TW_Command_Full firmware_command;
-       char data_buffer[1];
+       char data_buffer[];
 } TW_Ioctl_Buf_Apache;
 
 /* GetParam descriptor */
@@ -344,7 +344,7 @@ typedef struct {
        unsigned short  parameter_id;
        unsigned short  parameter_size_bytes;
        unsigned short  actual_parameter_size_bytes;
-       unsigned char   data[1];
+       unsigned char   data[];
 } TW_Param_Apache;
 
 /* Compatibility information structure */