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

From: Steven Rostedt
Date: Tue Sep 01 2015 - 10:04:21 EST


git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
for-next

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@xxxxxxxxxx>
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@xxxxxxxxxx

Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

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;
),

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