[tip:perf/core] ksym_tracer: NIL-terminate user input filter

tip-bot for Li Zefan
2009-11-21T13:36:32Z

Commit-ID: 011ed56853e07e30653d6f1bfddc56b396218664
Gitweb: http://git.kernel.org/tip/011ed56853e07e30653d6f1bfddc56b396218664
Author: Li Zefan <lizf@cn.fujitsu.com>
AuthorDate: Tue, 7 Jul 2009 13:54:08 +0800
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 10 Jul 2009 11:59:42 +0200

ksym_tracer: NIL-terminate user input filter

Make sure the user input string is NULL-terminated.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "K.Prasad" <prasad@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A52E300.7020601@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/trace/trace_ksym.c | 7 ++-----
1 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace_ksym.c b/kernel/trace/trace_ksym.c
index 72fcb46..8cbed5a 100644
--- a/kernel/trace/trace_ksym.c
+++ b/kernel/trace/trace_ksym.c
@@ -264,11 +264,7 @@ static ssize_t ksym_trace_filter_write(struct file *file,
unsigned long ksym_addr = 0;
int ret, op, changed = 0;

- /* Ignore echo "" > ksym_trace_filter */
- if (count == 0)
- return 0;
-
- input_string = kzalloc(count, GFP_KERNEL);
+ input_string = kzalloc(count + 1, GFP_KERNEL);
if (!input_string)
return -ENOMEM;

@@ -276,6 +272,7 @@ static ssize_t ksym_trace_filter_write(struct file *file,
kfree(input_string);
return -EFAULT;
}
+ input_string[count] = '\0';

ret = op = parse_ksym_trace_str(input_string, &ksymname, &ksym_addr);
if (ret < 0) {