[PATCH][BUG FIX] leds: Fix bug with reading NAS SS4200 dmi code

[PATCH][BUG FIX] leds: Fix bug with reading NAS SS4200 dmi code

[Steven Rostedt]

While running randconfg with ktest.pl I stumbled upon this bug:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000003
IP: [<ffffffff815fe44f>] strstr+0x39/0x86
PGD 0 
Oops: 0000 [#1] SMP 
last sysfs file: 
CPU 0 
Modules linked in:

Pid: 1, comm: swapper Not tainted 2.6.37-rc1-test+ #6 DG965MQ/        
RIP: 0010:[<ffffffff815fe44f>]  [<ffffffff815fe44f>] strstr+0x39/0x86
RSP: 0018:ffff8800797cbd80  EFLAGS: 00010213
RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffffffffffff
RDX: 0000000000000000 RSI: ffffffff82eb7ac9 RDI: 0000000000000003
RBP: ffff8800797cbda0 R08: ffff880000000003 R09: 0000000000030725
R10: ffff88007d294c00 R11: 0000000000014c00 R12: 0000000000000020
R13: ffffffff82eb7ac9 R14: ffffffffffffffff R15: ffffffff82eb7b08
FS:  0000000000000000(0000) GS:ffff88007d200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000003 CR3: 0000000002a1d000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 1, threadinfo ffff8800797ca000, task ffff8800797d0000)
Stack:
 00000000000000ba ffffffff82eb7ac9 ffffffff82eb7ab8 00000000000000ba
 ffff8800797cbdf0 ffffffff81e2050f ffff8800797cbdc0 00000000815f913b
 ffff8800797cbe00 ffffffff82eb7ab8 0000000000000000 0000000000000000
Call Trace:
 [<ffffffff81e2050f>] dmi_matches+0x117/0x154
 [<ffffffff81e205d7>] dmi_check_system+0x3d/0x8d
 [<ffffffff82e1ad25>] ? nas_gpio_init+0x0/0x2c8
 [<ffffffff82e1ad49>] nas_gpio_init+0x24/0x2c8
 [<ffffffff820d750d>] ? wm8350_led_init+0x0/0x20
 [<ffffffff82e1ad25>] ? nas_gpio_init+0x0/0x2c8
 [<ffffffff810022f7>] do_one_initcall+0xab/0x1b2
 [<ffffffff82da749c>] kernel_init+0x248/0x331
 [<ffffffff8100e624>] kernel_thread_helper+0x4/0x10
 [<ffffffff82da7254>] ? kernel_init+0x0/0x331


Found that the nas_led_whitelist dmi_system_id structure array had no
NULL end delimiter, causing the dmi_check_system() loop to read an
undefined entry.

Cc: Dave Hansen <dave@sr71.net>
Cc: Richard Purdie <rpurdie@linux.intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/drivers/leds/leds-ss4200.c b/drivers/leds/leds-ss4200.c
index a688293..614ebeb 100644
--- a/drivers/leds/leds-ss4200.c
+++ b/drivers/leds/leds-ss4200.c
@@ -102,6 +102,7 @@ static struct dmi_system_id __initdata nas_led_whitelist[] = {
 			DMI_MATCH(DMI_PRODUCT_VERSION, "1.00.00")
 		}
 	},
+	{}
 };
 
 /*

Re: [PATCH][BUG FIX] leds: Fix bug with reading NAS SS4200 dmi code

[Arjan van de Ven]

On 11/11/2010 6:34 PM, Steven Rostedt wrote:
> Found that the nas_led_whitelist dmi_system_id structure array had no
> NULL end delimiter, causing the dmi_check_system() loop to read an
> undefined entry.

Acked-by: Arjan van de Ven <arjan@linux.intel.com>

Re: [PATCH][BUG FIX] leds: Fix bug with reading NAS SS4200 dmi code

[Dave Hansen]

On Thu, 2010-11-11 at 21:34 -0500, Steven Rostedt wrote:
> Cc: Dave Hansen <dave@sr71.net>
> Cc: Richard Purdie <rpurdie@linux.intel.com>
> Cc: Arjan van de Ven <arjan@linux.intel.com>
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
> 
> diff --git a/drivers/leds/leds-ss4200.c b/drivers/leds/leds-ss4200.c
> index a688293..614ebeb 100644
> --- a/drivers/leds/leds-ss4200.c
> +++ b/drivers/leds/leds-ss4200.c
> @@ -102,6 +102,7 @@ static struct dmi_system_id __initdata
> nas_led_whitelist[] = {
>                         DMI_MATCH(DMI_PRODUCT_VERSION, "1.00.00")
>                 }
>         },
> +       {}
>  }; 

Urg.  I'm dumb.  Thanks, Steven.

Acked-by: Dave Hansen <dave@sr71.net>