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

Rasmus Andersen (rasmus@jaquet.dk)
Sun, 24 Jun 2001 23:06:06 +0200


Hi.

(My last mail to dougm@computone.com 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.

--- linux-245-ac16-clean/drivers/char/ip2main.c Sat May 19 20:58:17 2001
+++ linux-245-ac16/drivers/char/ip2main.c Sun Jun 24 22:37:27 2001
@@ -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

-- 
Regards,
        Rasmus(rasmus@jaquet.dk)

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