Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 28 Aug 2015 11:02:51 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] tracepoint: don't make assumptions about length of string on task rename |
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On Fri, 28 Aug 2015 07:06:58 -0400 Sasha Levin <sasha.levin@oracle.com> wrote:
> 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. > > Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Should this go to stable as well?
Also, as the memcpy was just faster than a strcpy, the static length was used. Perhaps we should convert that to a dynamic length string. But that should be a separate patch as this one fixes a possible bug, and the conversion to a dynamic string is just an enhancement.
-- Steve
> --- > include/trace/events/task.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/trace/events/task.h b/include/trace/events/task.h > index dee3bb1..2cca6cd 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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