[for-next][PATCH] tracing: Don't make assumptions about length of string on task rename

[for-next][PATCH] tracing: Don't make assumptions about length of string on task rename

[Steven Rostedt]

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
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Head SHA1: f0a515780393dffbb363e6d1567da46af6f3c5f3


Sasha Levin (1):
      tracing: Don't make assumptions about length of string on task rename

----
 include/trace/events/task.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---------------------------
commit f0a515780393dffbb363e6d1567da46af6f3c5f3
Author: Sasha Levin <sasha.levin@oracle.com>
Date:   Fri Aug 28 07:06:58 2015 -0400

    tracing: Don't make assumptions about length of string on task rename
    
    While the dest comm string size is assured to be at least TASK_COMM_LEN long,
    doing a memcpy() also adds the assumption that the source is at least that
    long as well, which isn't assured, and isn't true in cases such as:
    
    	set_task_comm(worker->task, "kworker/dying");
    
    This leads to accessing invalid memory.
    
    Link: http://lkml.kernel.org/r/1440760018-1557-1-git-send-email-sasha.levin@oracle.com
    
    Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
    Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/include/trace/events/task.h b/include/trace/events/task.h
index dee3bb1d5a6b..2cca6cd342d8 100644
--- a/include/trace/events/task.h
+++ b/include/trace/events/task.h
@@ -46,7 +46,7 @@ TRACE_EVENT(task_rename,
 	TP_fast_assign(
 		__entry->pid = task->pid;
 		memcpy(entry->oldcomm, task->comm, TASK_COMM_LEN);
-		memcpy(entry->newcomm, comm, TASK_COMM_LEN);
+		strlcpy(entry->newcomm, comm, TASK_COMM_LEN);
 		__entry->oom_score_adj = task->signal->oom_score_adj;
 	),