catch potential null derefs in drivers/char/ip2main.c (245ac16)

Hi.

(My last mail to [email protected] bounced. Is there another maintainer for drivers/char/ip2main.c somewhere?)

The patch below tries to avoid dereferencing (potential) NULL pointers. It was reported by the Stanford team way back and applies against 245ac16 and 246p6. It could probably be done nicer but that would take someone that actually understands this code.

drivers/char/ip2main.c +28 -26

@@ -866,36 +866,38 @@
 			}
 
 #ifdef	CONFIG_DEVFS_FS
-			sprintf( name, "ipl%d", i );
-			i2BoardPtrTable[i]->devfs_ipl_handle =
-				devfs_register (devfs_handle, name,
-					DEVFS_FL_DEFAULT,
-					IP2_IPL_MAJOR, 4 * i,
-					S_IRUSR | S_IWUSR | S_IRGRP | S_IFCHR,
-					&ip2_ipl, NULL);
+			if (i2BoardPtrTable[i] && pB) {
+				sprintf( name, "ipl%d", i );
+				i2BoardPtrTable[i]->devfs_ipl_handle =
+					devfs_register (devfs_handle, name,
+							DEVFS_FL_DEFAULT,
+							IP2_IPL_MAJOR, 4 * i,
+							S_IRUSR | S_IWUSR | S_IRGRP | S_IFCHR,
+							&ip2_ipl, NULL);
 
-			sprintf( name, "stat%d", i );
-			i2BoardPtrTable[i]->devfs_stat_handle =
-				devfs_register (devfs_handle, name,
-					DEVFS_FL_DEFAULT,
-					IP2_IPL_MAJOR, 4 * i + 1,
-					S_IRUSR | S_IWUSR | S_IRGRP | S_IFCHR,
-					&ip2_ipl, NULL);
+				sprintf( name, "stat%d", i );
+				i2BoardPtrTable[i]->devfs_stat_handle =
+					devfs_register (devfs_handle, name,
+							DEVFS_FL_DEFAULT,
+							IP2_IPL_MAJOR, 4 * i + 1,
+							S_IRUSR | S_IWUSR | S_IRGRP | S_IFCHR,
+							&ip2_ipl, NULL);
 
-			for ( box = 0; box < ABS_MAX_BOXES; ++box )
-			{
-			    for ( j = 0; j < ABS_BIGGEST_BOX; ++j )
-			    {
-				if ( pB->i2eChannelMap[box] & (1 << j) )
+				for ( box = 0; box < ABS_MAX_BOXES; ++box )
 				{
-				    tty_register_devfs(&ip2_tty_driver,
-					0, j + ABS_BIGGEST_BOX *
-						(box+i*ABS_MAX_BOXES));
-				    tty_register_devfs(&ip2_callout_driver,
-					0, j + ABS_BIGGEST_BOX *
-						(box+i*ABS_MAX_BOXES));
+					for ( j = 0; j < ABS_BIGGEST_BOX; ++j )
+					{
+						if ( pB->i2eChannelMap[box] & (1 << j) )
+						{
+							tty_register_devfs(&ip2_tty_driver,
+									   0, j + ABS_BIGGEST_BOX *
+									   (box+i*ABS_MAX_BOXES));
+							tty_register_devfs(&ip2_callout_driver,
+									   0, j + ABS_BIGGEST_BOX *
+									   (box+i*ABS_MAX_BOXES));
+						}
+					}
 				}
-			    }
 			}
 #endif
 

Signature · 7 lines

Regards,
        Rasmus([email protected])

A chicken and an egg are lying in bed. The chicken is smoking a
cigarette with a satisfied smile on it's face and the egg is frowning
and looking a bit pissed off. The egg mutters, to no-one in particular,
"Well, I guess we answered THAT question..."

Quoted 4 lines · Rasmus Andersen

Hi.

(My last mail to [email protected] bounced. Is there another maintainer for drivers/char/ip2main.c somewhere?)

I'm still here. :-) Just look one more line down below
Doug's line. There I am.

I'm responsible for the kernel / driver integration end of it
anyways.

I'll find out what's up with Doug, but this is my issue to deal
with anyways. And yes, I'm looking at it. I've got a couple of other patches on the back burner that are overdue for integration.

drivers/char/ip2main.c line 887

Quoted 7 lines

drivers/char/ip2main.c +1 -5

-			for ( box = 0; box < ABS_MAX_BOXES; ++box )
-			{
-			    for ( j = 0; j < ABS_BIGGEST_BOX; ++j )
-			    {
-				if ( pB->i2eChannelMap[box] & (1 << j) )
+				for ( box = 0; box < ABS_MAX_BOXES; ++box )
 				{