scsi: aacraid: aachba: Replace snprintf() with the safer scnprintf() variant

There is a general misunderstanding amongst engineers that {v}snprintf()
returns the length of the data *actually* encoded into the destination
array.  However, as per the C99 standard {v}snprintf() really returns
the length of the data that *would have been* written if there were
enough space for it.  This misunderstanding has led to buffer-overruns
in the past.  It's generally considered safer to use the {v}scnprintf()
variants in their place (or even sprintf() in simple cases).  So let's
do that.

Link: https://lwn.net/Articles/69419/
Link: https://github.com/KSPP/linux/issues/105
Cc: Adaptec OEM Raid Solutions <aacraid@microsemi.com>
Cc: PMC-Sierra, Inc <aacraid@pmc-sierra.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20240111131732.1815560-6-lee@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index 70e1cac1975ebedb6608890f756775a0d13b5ffc..b22857c6f3f4f93b92f3e1929a12ffb1084e8b64 100644 (file)
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -1099,7 +1099,7 @@ static void get_container_serial_callback(void *context, struct fib * fibptr)
                        sp[0] = INQD_PDT_DA;
                        sp[1] = scsicmd->cmnd[2];
                        sp[2] = 0;
-                       sp[3] = snprintf(sp+4, sizeof(sp)-4, "%08X",
+                       sp[3] = scnprintf(sp+4, sizeof(sp)-4, "%08X",
                                le32_to_cpu(get_serial_reply->uid));
                        scsi_sg_copy_from_buffer(scsicmd, sp,
                                                 sizeof(sp));
@@ -1169,8 +1169,8 @@ static int setinqserial(struct aac_dev *dev, void *data, int cid)
        /*
         *      This breaks array migration.
         */
-       return snprintf((char *)(data), sizeof(struct scsi_inq) - 4, "%08X%02X",
-                       le32_to_cpu(dev->adapter_info.serial[0]), cid);
+       return scnprintf((char *)(data), sizeof(struct scsi_inq) - 4, "%08X%02X",
+                        le32_to_cpu(dev->adapter_info.serial[0]), cid);
 }
 
 static inline void set_sense(struct sense_data *sense_data, u8 sense_key,