From dc81e5e3abb9f98a3cb6f269c0bee595b2c1235d Mon Sep 17 00:00:00 2001 From: Yoshihiro YUNOMAE Date: Fri, 6 Jun 2014 07:35:17 +0900 Subject: [PATCH] tracing: Return error if ftrace_trace_arrays list is empty ftrace_trace_arrays links global_trace.list. However, global_trace is not added to ftrace_trace_arrays if trace_alloc_buffers() failed. As the result, ftrace_trace_arrays becomes an empty list. If ftrace_trace_arrays is an empty list, current top_trace_array() returns an invalid pointer. As the result, the kernel can induce memory corruption or panic. Current implementation does not check whether ftrace_trace_arrays is empty list or not. So, in this patch, if ftrace_trace_arrays is empty list, top_trace_array() returns NULL. Moreover, this patch makes all functions calling top_trace_array() handle it appropriately. Link: http://lkml.kernel.org/p/20140605223517.32311.99233.stgit@yunodevel Signed-off-by: Yoshihiro YUNOMAE Signed-off-by: Steven Rostedt --- Reading git-format-patch failed