5.4-stable review patch. If anyone has any objections, please let me know.
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From: guoweikang guoweikang.kernel@gmail.com
commit 45af52e7d3b8560f21d139b3759735eead8b1653 upstream.
When executing the following command:
# echo "write*:mod:ext3" > /sys/kernel/tracing/stack_trace_filter
The current mod command causes a null pointer dereference. While commit 0f17976568b3f ("ftrace: Fix regression with module command in stack_trace_filter") has addressed part of the issue, it left a corner case unhandled, which still results in a kernel crash.
Cc: stable@vger.kernel.org Cc: Masami Hiramatsu mhiramat@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Mathieu Desnoyers mathieu.desnoyers@efficios.com Link: https://lore.kernel.org/20241120052750.275463-1-guoweikang.kernel@gmail.com Fixes: 04ec7bb642b77 ("tracing: Have the trace_array hold the list of registered func probes"); Signed-off-by: guoweikang guoweikang.kernel@gmail.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/trace/ftrace.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4132,6 +4132,9 @@ ftrace_mod_callback(struct trace_array * char *func; int ret;
+ if (!tr) + return -ENODEV; + /* match_records() modifies func, and we need the original */ func = kstrdup(func_orig, GFP_KERNEL); if (!func)