Commit df091625 authored Sep 09, 2010 by Chris Wright Committed by Steven Rostedt Sep 09, 2010

tracing: t_start: reset FTRACE_ITER_HASH in case of seek/pread

Be sure to avoid entering t_show() with FTRACE_ITER_HASH set without
having properly started the iterator to iterate the hash.  This case is
degenerate and, as discovered by Robert Swiecki, can cause t_hash_show()
to misuse a pointer.  This causes a NULL ptr deref with possible security
implications.  Tracked as CVE-2010-3079.

Cc: Robert Swiecki <swiecki@google.com>
Cc: Eugene Teo <eugene@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent 5e11637e

kernel/trace/ftrace.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1510,6 +1510,8 @@ static void t_start(struct seq_file m, loff_t *pos)
		if (*pos > 0)
		return t_hash_start(m, pos);
		iter->flags \|= FTRACE_ITER_PRINTALL;
		/* reset in case of seek/pread */
		iter->flags &= ~FTRACE_ITER_HASH;
		return iter;
		}

Admin message