Namhyung Kim discovered a use after free bug. It has to do with adding

a pid filter to function tracing in an instance, and then freeing
 the instance.
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Merge tag 'trace-v4.11-rc5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull ftrace fix from Steven Rostedt:
 "Namhyung Kim discovered a use after free bug. It has to do with adding
  a pid filter to function tracing in an instance, and then freeing the
  instance"

* tag 'trace-v4.11-rc5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix function pid filter on instances
This commit is contained in:
Linus Torvalds 2017-04-18 09:31:51 -07:00
commit 0bad6d7e93
3 changed files with 12 additions and 0 deletions

View File

@ -5566,6 +5566,15 @@ static void clear_ftrace_pids(struct trace_array *tr)
trace_free_pid_list(pid_list);
}
void ftrace_clear_pids(struct trace_array *tr)
{
mutex_lock(&ftrace_lock);
clear_ftrace_pids(tr);
mutex_unlock(&ftrace_lock);
}
static void ftrace_pid_reset(struct trace_array *tr)
{
mutex_lock(&ftrace_lock);

View File

@ -7402,6 +7402,7 @@ static int instance_rmdir(const char *name)
tracing_set_nop(tr);
event_trace_del_tracer(tr);
ftrace_clear_pids(tr);
ftrace_destroy_function_files(tr);
tracefs_remove_recursive(tr->dir);
free_trace_buffers(tr);

View File

@ -896,6 +896,7 @@ int using_ftrace_ops_list_func(void);
void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
void ftrace_init_tracefs_toplevel(struct trace_array *tr,
struct dentry *d_tracer);
void ftrace_clear_pids(struct trace_array *tr);
#else
static inline int ftrace_trace_task(struct trace_array *tr)
{
@ -914,6 +915,7 @@ ftrace_init_global_array_ops(struct trace_array *tr) { }
static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
static inline void ftrace_clear_pids(struct trace_array *tr) { }
/* ftace_func_t type is not defined, use macro instead of static inline */
#define ftrace_init_array_ops(tr, func) do { } while (0)
#endif /* CONFIG_FUNCTION_TRACER */