Commit 74bf4076 authored Jan 25, 2010 by Steven Rostedt Committed by Steven Rostedt Jan 25, 2010

tracing: Prevent kernel oops with corrupted buffer



If the contents of the ftrace ring buffer gets corrupted and the trace
file is read, it could create a kernel oops (usualy just killing the user
task thread). This is caused by the checking of the pid in the buffer.
If the pid is negative, it still references the cmdline cache array,
which could point to an invalid address.

The simple fix is to test for negative PIDs.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent f6760aa0

kernel/trace/trace.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -951,6 +951,11 @@ void trace_find_cmdline(int pid, char comm[])
		return;
		}

		if (WARN_ON_ONCE(pid < 0)) {
		strcpy(comm, "<XXX>");
		return;
		}

		if (pid > PID_MAX_DEFAULT) {
		strcpy(comm, "<...>");
		return;

Admin message