scsi: aacraid: Use scnprintf() for avoiding potential buffer overflow

Since snprintf() returns the would-be-output size instead of the actual
output size, the succeeding calls may go beyond the given buffer limit.
Fix it by replacing with scnprintf().

Link: https://lore.kernel.org/r/20200315094241.9086-2-tiwai@suse.de
Cc: "James E . J . Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K . Petersen" <martin.petersen@oracle.com>
Cc: Adaptec OEM Raid Solutions <aacraid@microsemi.com>
Cc: linux-scsi@vger.kernel.org
Acked-by: Balsundar P <Balsundar.P@microchip.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index b1d133de29ab5ff72eaab6df34683094ffa2c5ae..8b583eec25b5192648252c97a42c42d43d24231a 100644 (file)
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -1287,20 +1287,21 @@ static ssize_t aac_show_flags(struct device *cdev,
        if (nblank(dprintk(x)))
                len = snprintf(buf, PAGE_SIZE, "dprintk\n");
 #ifdef AAC_DETAILED_STATUS_INFO
-       len += snprintf(buf + len, PAGE_SIZE - len,
-                       "AAC_DETAILED_STATUS_INFO\n");
+       len += scnprintf(buf + len, PAGE_SIZE - len,
+                        "AAC_DETAILED_STATUS_INFO\n");
 #endif
        if (dev->raw_io_interface && dev->raw_io_64)
-               len += snprintf(buf + len, PAGE_SIZE - len,
-                               "SAI_READ_CAPACITY_16\n");
+               len += scnprintf(buf + len, PAGE_SIZE - len,
+                                "SAI_READ_CAPACITY_16\n");
        if (dev->jbod)
-               len += snprintf(buf + len, PAGE_SIZE - len, "SUPPORTED_JBOD\n");
+               len += scnprintf(buf + len, PAGE_SIZE - len,
+                                "SUPPORTED_JBOD\n");
        if (dev->supplement_adapter_info.supported_options2 &
                AAC_OPTION_POWER_MANAGEMENT)
-               len += snprintf(buf + len, PAGE_SIZE - len,
-                               "SUPPORTED_POWER_MANAGEMENT\n");
+               len += scnprintf(buf + len, PAGE_SIZE - len,
+                                "SUPPORTED_POWER_MANAGEMENT\n");
        if (dev->msi)
-               len += snprintf(buf + len, PAGE_SIZE - len, "PCI_HAS_MSI\n");
+               len += scnprintf(buf + len, PAGE_SIZE - len, "PCI_HAS_MSI\n");
        return len;
 }