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

[Li Zefan]

Commit-ID:  9eb85125ce218a8b8d9a7c982510388e227adbec
Gitweb:     http://git.kernel.org/tip/9eb85125ce218a8b8d9a7c982510388e227adbec
Author:     Li Zefan <lizf@xxxxxxxxxxxxxx>
AuthorDate: Thu, 9 Apr 2009 11:19:40 +0800
Committer:  Ingo Molnar <mingo@xxxxxxx>
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 <lizf@xxxxxxxxxxxxxx>
Cc: Jens Axboe <jens.axboe@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
LKML-Reference: <49DD694C.8020902@xxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
 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;
 }
--
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