2009-04-09 03:19:18

by Li Zefan

Subject: [PATCH] blktrace: pass the right pointer to kfree()

If passing a string with leading white spaces to strstrip(),
the returned ptr != the original ptr.

This bug was introduced by me.

Signed-off-by: Li Zefan <[email protected]>
---
kernel/trace/blktrace.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index b32ff44..921ef5d 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1377,12 +1377,12 @@ static int blk_trace_str2mask(const char *str)
{
int i;
int mask = 0;
- char *s, *token;
+ char *buf, *s, *token;

- s = kstrdup(str, GFP_KERNEL);
- if (s == NULL)
+ buf = kstrdup(str, GFP_KERNEL);
+ if (buf == NULL)
return -ENOMEM;
- s = strstrip(s);
+ s = strstrip(buf);

while (1) {
token = strsep(&s, ",");
@@ -1403,7 +1403,7 @@ static int blk_trace_str2mask(const char *str)
break;
}
}
- kfree(s);
+ kfree(buf);

return mask;
}
--
1.5.4.rc3

2009-04-09 04:37:43

by Li Zefan

Subject: [tip:tracing/urgent] blktrace: pass the right pointer to kfree()

Commit-ID: 9eb85125ce218a8b8d9a7c982510388e227adbec
Gitweb: http://git.kernel.org/tip/9eb85125ce218a8b8d9a7c982510388e227adbec
Author: Li Zefan <[email protected]>
AuthorDate: Thu, 9 Apr 2009 11:19:40 +0800
Committer: Ingo Molnar <[email protected]>
CommitDate: Thu, 9 Apr 2009 05:52:40 +0200

blktrace: pass the right pointer to kfree()

Impact: fix kfree crash with non-standard act_mask string

If passing a string with leading white spaces to strstrip(),
the returned ptr != the original ptr.

This bug was introduced by me.

Signed-off-by: Li Zefan <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>


---
kernel/trace/blktrace.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index b32ff44..921ef5d 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1377,12 +1377,12 @@ static int blk_trace_str2mask(const char *str)
{
int i;
int mask = 0;
- char *s, *token;
+ char *buf, *s, *token;

- s = kstrdup(str, GFP_KERNEL);
- if (s == NULL)
+ buf = kstrdup(str, GFP_KERNEL);
+ if (buf == NULL)
return -ENOMEM;
- s = strstrip(s);
+ s = strstrip(buf);

while (1) {
token = strsep(&s, ",");
@@ -1403,7 +1403,7 @@ static int blk_trace_str2mask(const char *str)
break;
}
}
- kfree(s);
+ kfree(buf);

return mask;
}

2009-04-09 13:13:48

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH] blktrace: pass the right pointer to kfree()

Em Thu, Apr 09, 2009 at 11:19:40AM +0800, Li Zefan escreveu:
> If passing a string with leading white spaces to strstrip(),
> the returned ptr != the original ptr.
>
> This bug was introduced by me.
>
> Signed-off-by: Li Zefan <[email protected]>

I hadn't noticed that strstrip was added, oops.

Acked-by: Arnaldo Carvalho de Melo <[email protected]>

> ---
> kernel/trace/blktrace.c | 10 +++++-----
> 1 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
> index b32ff44..921ef5d 100644
> --- a/kernel/trace/blktrace.c
> +++ b/kernel/trace/blktrace.c
> @@ -1377,12 +1377,12 @@ static int blk_trace_str2mask(const char *str)
> {
> int i;
> int mask = 0;
> - char *s, *token;
> + char *buf, *s, *token;
>
> - s = kstrdup(str, GFP_KERNEL);
> - if (s == NULL)
> + buf = kstrdup(str, GFP_KERNEL);
> + if (buf == NULL)
> return -ENOMEM;
> - s = strstrip(s);
> + s = strstrip(buf);
>
> while (1) {
> token = strsep(&s, ",");
> @@ -1403,7 +1403,7 @@ static int blk_trace_str2mask(const char *str)
> break;
> }
> }
> - kfree(s);
> + kfree(buf);
>
> return mask;
> }
> --
> 1.5.4.rc3