scsi: aacraid: Fix udev inquiry race condition

When udev requests for a devices inquiry string, it might create multiple
threads causing a race condition on the shared inquiry resource string.

Created a buffer with the string for each thread.

Cc: <stable@vger.kernel.org>
Fixes: 3bc8070f ([SCSI] aacraid: SMC vendor identification)
Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/aacraid/aachba.c

@@ -913,8 +913,16 @@ static void setinqstr(struct aac_dev *dev, void *data, int tindex)
 	memset(str, ' ', sizeof(*str));
 
 	if (sup_adap_info->adapter_type_text[0]) {
-		char *cp = sup_adap_info->adapter_type_text;
 		int c;
+		char *cp;
+		char *cname = kmemdup(sup_adap_info->adapter_type_text,
+				sizeof(sup_adap_info->adapter_type_text),
+								GFP_ATOMIC);
+
+		if (!cname)
+			return;
+
+		cp = cname;
 		if ((cp[0] == 'A') && (cp[1] == 'O') && (cp[2] == 'C'))
 			inqstrcpy("SMC", str->vid);
 		else {
@@ -923,7 +931,7 @@ static void setinqstr(struct aac_dev *dev, void *data, int tindex)
 				++cp;
 			c = *cp;
 			*cp = '\0';
-			inqstrcpy(sup_adap_info->adapter_type_text, str->vid);
+			inqstrcpy(cname, str->vid);
 			*cp = c;
 			while (*cp && *cp != ' ')
 				++cp;
@@ -937,8 +945,8 @@ static void setinqstr(struct aac_dev *dev, void *data, int tindex)
 			cp[sizeof(str->pid)] = '\0';
 		}
 		inqstrcpy (cp, str->pid);
-		if (c)
-			cp[sizeof(str->pid)] = c;
+
+		kfree(cname);
 	} else {
 		struct aac_driver_ident *mp = aac_get_driver_ident(dev->cardtype);