2012-08-02 11:05:47

by Fengguang Wu

[permalink] [raw]
Subject: [PATCH] isdnloop: fix and simplify isdnloop_init()

Fix a buffer overflow bug by removing the revision transform code.

[ 22.016214] isdnloop-ISDN-driver Rev 1.11.6.7
[ 22.097508] isdnloop: (loop0) virtual card added
[ 22.174400] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff83244972
[ 22.174400]
[ 22.436157] Pid: 1, comm: swapper Not tainted 3.5.0-bisect-00018-gfa8bbb1-dirty #129
[ 22.624071] Call Trace:
[ 22.720558] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
[ 22.815248] [<ffffffff8222b623>] panic+0x110/0x329
[ 22.914330] [<ffffffff83244972>] ? isdnloop_init+0xaf/0xb1
[ 23.014800] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
[ 23.090763] [<ffffffff8108e24b>] __stack_chk_fail+0x2b/0x30
[ 23.185748] [<ffffffff83244972>] isdnloop_init+0xaf/0xb1

Signed-off-by: Fengguang Wu <[email protected]>
---
drivers/isdn/isdnloop/isdnloop.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)

--- linux.orig/drivers/isdn/isdnloop/isdnloop.c 2012-05-24 19:03:06.748430938 +0800
+++ linux/drivers/isdn/isdnloop/isdnloop.c 2012-08-02 11:57:16.806437909 +0800
@@ -16,7 +16,7 @@
#include <linux/sched.h>
#include "isdnloop.h"

-static char *revision = "$Revision: 1.11.6.7 $";
+static char *revision = "1.11.6.7";
static char *isdnloop_id = "loop0";

MODULE_DESCRIPTION("ISDN4Linux: Pseudo Driver that simulates an ISDN card");
@@ -1494,16 +1494,7 @@ isdnloop_addcard(char *id1)
static int __init
isdnloop_init(void)
{
- char *p;
- char rev[10];
-
- if ((p = strchr(revision, ':'))) {
- strcpy(rev, p + 1);
- p = strchr(rev, '$');
- *p = 0;
- } else
- strcpy(rev, " ??? ");
- printk(KERN_NOTICE "isdnloop-ISDN-driver Rev%s\n", rev);
+ printk(KERN_NOTICE "isdnloop-ISDN-driver Rev %s\n", revision);

if (isdnloop_id)
return (isdnloop_addcard(isdnloop_id));


2012-08-02 23:21:58

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] isdnloop: fix and simplify isdnloop_init()

From: Fengguang Wu <[email protected]>
Date: Thu, 2 Aug 2012 19:05:43 +0800

> Fix a buffer overflow bug by removing the revision transform code.
>
> [ 22.016214] isdnloop-ISDN-driver Rev 1.11.6.7
> [ 22.097508] isdnloop: (loop0) virtual card added
> [ 22.174400] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff83244972
> [ 22.174400]
> [ 22.436157] Pid: 1, comm: swapper Not tainted 3.5.0-bisect-00018-gfa8bbb1-dirty #129
> [ 22.624071] Call Trace:
> [ 22.720558] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
> [ 22.815248] [<ffffffff8222b623>] panic+0x110/0x329
> [ 22.914330] [<ffffffff83244972>] ? isdnloop_init+0xaf/0xb1
> [ 23.014800] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
> [ 23.090763] [<ffffffff8108e24b>] __stack_chk_fail+0x2b/0x30
> [ 23.185748] [<ffffffff83244972>] isdnloop_init+0xaf/0xb1
>
> Signed-off-by: Fengguang Wu <[email protected]>

The reason the "$Revision ..." prefix is there is so that automated
version control tools will change the string automatically when code
is committed in CVS.

In the GIT era this revision style is obsolete.

Therefore you might as well just delete this crap altogether.

2012-08-03 07:32:50

by Fengguang Wu

[permalink] [raw]
Subject: [PATCH v2] isdnloop: fix and simplify isdnloop_init()

On Thu, Aug 02, 2012 at 04:21:56PM -0700, David Miller wrote:
> From: Fengguang Wu <[email protected]>
> Date: Thu, 2 Aug 2012 19:05:43 +0800
>
> > Fix a buffer overflow bug by removing the revision transform code.
> >
> > [ 22.016214] isdnloop-ISDN-driver Rev 1.11.6.7
> > [ 22.097508] isdnloop: (loop0) virtual card added
> > [ 22.174400] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff83244972
> > [ 22.174400]
> > [ 22.436157] Pid: 1, comm: swapper Not tainted 3.5.0-bisect-00018-gfa8bbb1-dirty #129
> > [ 22.624071] Call Trace:
> > [ 22.720558] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
> > [ 22.815248] [<ffffffff8222b623>] panic+0x110/0x329
> > [ 22.914330] [<ffffffff83244972>] ? isdnloop_init+0xaf/0xb1
> > [ 23.014800] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
> > [ 23.090763] [<ffffffff8108e24b>] __stack_chk_fail+0x2b/0x30
> > [ 23.185748] [<ffffffff83244972>] isdnloop_init+0xaf/0xb1
> >
> > Signed-off-by: Fengguang Wu <[email protected]>
>
> The reason the "$Revision ..." prefix is there is so that automated
> version control tools will change the string automatically when code
> is committed in CVS.
>
> In the GIT era this revision style is obsolete.
>
> Therefore you might as well just delete this crap altogether.

OK. The below updated version will simply print the hard coded
revision number as it's unlikely to change any more.

Thanks,
Fengguang
---
isdnloop: fix and simplify isdnloop_init

Fix a buffer overflow bug by hard coding the revision number.

[ 22.016214] isdnloop-ISDN-driver Rev 1.11.6.7
[ 22.097508] isdnloop: (loop0) virtual card added
[ 22.174400] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff83244972
[ 22.174400]
[ 22.436157] Pid: 1, comm: swapper Not tainted 3.5.0-bisect-00018-gfa8bbb1-dirty #129
[ 22.624071] Call Trace:
[ 22.720558] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
[ 22.815248] [<ffffffff8222b623>] panic+0x110/0x329
[ 22.914330] [<ffffffff83244972>] ? isdnloop_init+0xaf/0xb1
[ 23.014800] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
[ 23.090763] [<ffffffff8108e24b>] __stack_chk_fail+0x2b/0x30
[ 23.185748] [<ffffffff83244972>] isdnloop_init+0xaf/0xb1

Signed-off-by: Fengguang Wu <[email protected]>
---
drivers/isdn/isdnloop/isdnloop.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)

--- linux.orig/drivers/isdn/isdnloop/isdnloop.c 2012-08-03 15:24:49.047544323 +0800
+++ linux/drivers/isdn/isdnloop/isdnloop.c 2012-08-03 15:27:39.503548375 +0800
@@ -16,7 +16,6 @@
#include <linux/sched.h>
#include "isdnloop.h"

-static char *revision = "$Revision: 1.11.6.7 $";
static char *isdnloop_id = "loop0";

MODULE_DESCRIPTION("ISDN4Linux: Pseudo Driver that simulates an ISDN card");
@@ -1494,16 +1493,7 @@ isdnloop_addcard(char *id1)
static int __init
isdnloop_init(void)
{
- char *p;
- char rev[10];
-
- if ((p = strchr(revision, ':'))) {
- strcpy(rev, p + 1);
- p = strchr(rev, '$');
- *p = 0;
- } else
- strcpy(rev, " ??? ");
- printk(KERN_NOTICE "isdnloop-ISDN-driver Rev%s\n", rev);
+ printk(KERN_NOTICE "isdnloop-ISDN-driver Rev 1.11.6.7\n");

if (isdnloop_id)
return (isdnloop_addcard(isdnloop_id));

2012-08-03 08:48:20

by Karsten Keil

[permalink] [raw]
Subject: Re: [PATCH v2] isdnloop: fix and simplify isdnloop_init()

Am 03.08.2012 09:32, schrieb Fengguang Wu:
> On Thu, Aug 02, 2012 at 04:21:56PM -0700, David Miller wrote:
>> From: Fengguang Wu <[email protected]>
>> Date: Thu, 2 Aug 2012 19:05:43 +0800
>>
>>> Fix a buffer overflow bug by removing the revision transform code.
>>>
>>> [ 22.016214] isdnloop-ISDN-driver Rev 1.11.6.7
>>> [ 22.097508] isdnloop: (loop0) virtual card added
>>> [ 22.174400] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff83244972
>>> [ 22.174400]
>>> [ 22.436157] Pid: 1, comm: swapper Not tainted 3.5.0-bisect-00018-gfa8bbb1-dirty #129
>>> [ 22.624071] Call Trace:
>>> [ 22.720558] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
>>> [ 22.815248] [<ffffffff8222b623>] panic+0x110/0x329
>>> [ 22.914330] [<ffffffff83244972>] ? isdnloop_init+0xaf/0xb1
>>> [ 23.014800] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
>>> [ 23.090763] [<ffffffff8108e24b>] __stack_chk_fail+0x2b/0x30
>>> [ 23.185748] [<ffffffff83244972>] isdnloop_init+0xaf/0xb1
>>>
>>> Signed-off-by: Fengguang Wu <[email protected]>
>>
>> The reason the "$Revision ..." prefix is there is so that automated
>> version control tools will change the string automatically when code
>> is committed in CVS.
>>
>> In the GIT era this revision style is obsolete.
>>
>> Therefore you might as well just delete this crap altogether.
>
> OK. The below updated version will simply print the hard coded
> revision number as it's unlikely to change any more.
>
> Thanks,
> Fengguang
> ---
> isdnloop: fix and simplify isdnloop_init
>
> Fix a buffer overflow bug by hard coding the revision number.
>
> [ 22.016214] isdnloop-ISDN-driver Rev 1.11.6.7
> [ 22.097508] isdnloop: (loop0) virtual card added
> [ 22.174400] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff83244972
> [ 22.174400]
> [ 22.436157] Pid: 1, comm: swapper Not tainted 3.5.0-bisect-00018-gfa8bbb1-dirty #129
> [ 22.624071] Call Trace:
> [ 22.720558] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
> [ 22.815248] [<ffffffff8222b623>] panic+0x110/0x329
> [ 22.914330] [<ffffffff83244972>] ? isdnloop_init+0xaf/0xb1
> [ 23.014800] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
> [ 23.090763] [<ffffffff8108e24b>] __stack_chk_fail+0x2b/0x30
> [ 23.185748] [<ffffffff83244972>] isdnloop_init+0xaf/0xb1
>
> Signed-off-by: Fengguang Wu <[email protected]>
> ---
> drivers/isdn/isdnloop/isdnloop.c | 12 +-----------
> 1 file changed, 1 insertion(+), 11 deletions(-)
>
> --- linux.orig/drivers/isdn/isdnloop/isdnloop.c 2012-08-03 15:24:49.047544323 +0800
> +++ linux/drivers/isdn/isdnloop/isdnloop.c 2012-08-03 15:27:39.503548375 +0800
> @@ -16,7 +16,6 @@
> #include <linux/sched.h>
> #include "isdnloop.h"
>
> -static char *revision = "$Revision: 1.11.6.7 $";
> static char *isdnloop_id = "loop0";
>
> MODULE_DESCRIPTION("ISDN4Linux: Pseudo Driver that simulates an ISDN card");
> @@ -1494,16 +1493,7 @@ isdnloop_addcard(char *id1)
> static int __init
> isdnloop_init(void)
> {
> - char *p;
> - char rev[10];
> -
> - if ((p = strchr(revision, ':'))) {
> - strcpy(rev, p + 1);
> - p = strchr(rev, '$');
> - *p = 0;
> - } else
> - strcpy(rev, " ??? ");
> - printk(KERN_NOTICE "isdnloop-ISDN-driver Rev%s\n", rev);
> + printk(KERN_NOTICE "isdnloop-ISDN-driver Rev 1.11.6.7\n");
>
> if (isdnloop_id)
> return (isdnloop_addcard(isdnloop_id));
>
>
You could remove the revision completely, even from the printk.
Maybe use pr_notice("isdnloop-ISDN driver loaded\n");

Best Regards
Karsten

2012-08-03 08:51:33

by David Miller

[permalink] [raw]
Subject: Re: [PATCH v2] isdnloop: fix and simplify isdnloop_init()

From: Fengguang Wu <[email protected]>
Date: Fri, 3 Aug 2012 15:32:40 +0800

> On Thu, Aug 02, 2012 at 04:21:56PM -0700, David Miller wrote:
>> From: Fengguang Wu <[email protected]>
>> Date: Thu, 2 Aug 2012 19:05:43 +0800
>>
>> > Fix a buffer overflow bug by removing the revision transform code.
>> >
>> > [ 22.016214] isdnloop-ISDN-driver Rev 1.11.6.7
>> > [ 22.097508] isdnloop: (loop0) virtual card added
>> > [ 22.174400] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff83244972
>> > [ 22.174400]
>> > [ 22.436157] Pid: 1, comm: swapper Not tainted 3.5.0-bisect-00018-gfa8bbb1-dirty #129
>> > [ 22.624071] Call Trace:
>> > [ 22.720558] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
>> > [ 22.815248] [<ffffffff8222b623>] panic+0x110/0x329
>> > [ 22.914330] [<ffffffff83244972>] ? isdnloop_init+0xaf/0xb1
>> > [ 23.014800] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
>> > [ 23.090763] [<ffffffff8108e24b>] __stack_chk_fail+0x2b/0x30
>> > [ 23.185748] [<ffffffff83244972>] isdnloop_init+0xaf/0xb1
>> >
>> > Signed-off-by: Fengguang Wu <[email protected]>
>>
>> The reason the "$Revision ..." prefix is there is so that automated
>> version control tools will change the string automatically when code
>> is committed in CVS.
>>
>> In the GIT era this revision style is obsolete.
>>
>> Therefore you might as well just delete this crap altogether.
>
> OK. The below updated version will simply print the hard coded
> revision number as it's unlikely to change any more.

This is worse, I said delete this crap altogether.

2012-08-03 09:10:11

by Fengguang Wu

[permalink] [raw]
Subject: [PATCH v3] isdnloop: fix and simplify isdnloop_init()

Fix a buffer overflow bug by removing the revision and printk.

[ 22.016214] isdnloop-ISDN-driver Rev 1.11.6.7
[ 22.097508] isdnloop: (loop0) virtual card added
[ 22.174400] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff83244972
[ 22.174400]
[ 22.436157] Pid: 1, comm: swapper Not tainted 3.5.0-bisect-00018-gfa8bbb1-dirty #129
[ 22.624071] Call Trace:
[ 22.720558] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
[ 22.815248] [<ffffffff8222b623>] panic+0x110/0x329
[ 22.914330] [<ffffffff83244972>] ? isdnloop_init+0xaf/0xb1
[ 23.014800] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
[ 23.090763] [<ffffffff8108e24b>] __stack_chk_fail+0x2b/0x30
[ 23.185748] [<ffffffff83244972>] isdnloop_init+0xaf/0xb1

Signed-off-by: Fengguang Wu <[email protected]>
---
drivers/isdn/isdnloop/isdnloop.c | 12 ------------
1 file changed, 12 deletions(-)

--- linux.orig/drivers/isdn/isdnloop/isdnloop.c 2012-08-03 16:39:08.543650310 +0800
+++ linux/drivers/isdn/isdnloop/isdnloop.c 2012-08-03 17:08:07.515691639 +0800
@@ -16,7 +16,6 @@
#include <linux/sched.h>
#include "isdnloop.h"

-static char *revision = "$Revision: 1.11.6.7 $";
static char *isdnloop_id = "loop0";

MODULE_DESCRIPTION("ISDN4Linux: Pseudo Driver that simulates an ISDN card");
@@ -1494,17 +1493,6 @@ isdnloop_addcard(char *id1)
static int __init
isdnloop_init(void)
{
- char *p;
- char rev[10];
-
- if ((p = strchr(revision, ':'))) {
- strcpy(rev, p + 1);
- p = strchr(rev, '$');
- *p = 0;
- } else
- strcpy(rev, " ??? ");
- printk(KERN_NOTICE "isdnloop-ISDN-driver Rev%s\n", rev);
-
if (isdnloop_id)
return (isdnloop_addcard(isdnloop_id));

2012-08-03 23:53:44

by David Miller

[permalink] [raw]
Subject: Re: [PATCH v3] isdnloop: fix and simplify isdnloop_init()

From: Fengguang Wu <[email protected]>
Date: Fri, 3 Aug 2012 17:10:01 +0800

> Fix a buffer overflow bug by removing the revision and printk.
>
> [ 22.016214] isdnloop-ISDN-driver Rev 1.11.6.7
> [ 22.097508] isdnloop: (loop0) virtual card added
> [ 22.174400] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff83244972
> [ 22.174400]
> [ 22.436157] Pid: 1, comm: swapper Not tainted 3.5.0-bisect-00018-gfa8bbb1-dirty #129
> [ 22.624071] Call Trace:
> [ 22.720558] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
> [ 22.815248] [<ffffffff8222b623>] panic+0x110/0x329
> [ 22.914330] [<ffffffff83244972>] ? isdnloop_init+0xaf/0xb1
> [ 23.014800] [<ffffffff832448c3>] ? CallcNew+0x56/0x56
> [ 23.090763] [<ffffffff8108e24b>] __stack_chk_fail+0x2b/0x30
> [ 23.185748] [<ffffffff83244972>] isdnloop_init+0xaf/0xb1
>
> Signed-off-by: Fengguang Wu <[email protected]>

Applied.