diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f93e34dd2328..6c47a94f5924 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1097,6 +1097,12 @@ struct ftrace_ops global_ops = { FTRACE_OPS_FL_PID, }; +/* + * parser_lock - Protects trace_parser state against concurrent operations. + * Held across trace_get_user() and subsequent buffer parsing to prevent races. + */ +static DEFINE_MUTEX(parser_lock); + /* * Used by the stack unwinder to know about dynamic ftrace trampolines. */ @@ -5842,6 +5848,8 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, /* iter->hash is a local copy, so we don't need regex_lock */ parser = &iter->parser; + + guard(mutex)(&parser_lock); read = trace_get_user(parser, ubuf, cnt, ppos); if (read >= 0 && trace_parser_loaded(parser) && @@ -6984,12 +6992,14 @@ int ftrace_regex_release(struct inode *inode, struct file *file) iter = file->private_data; parser = &iter->parser; + mutex_lock(&parser_lock); if (trace_parser_loaded(parser)) { int enable = !(iter->flags & FTRACE_ITER_NOTRACE); ftrace_process_regex(iter, parser->buffer, parser->idx, enable); } + mutex_unlock(&parser_lock); trace_parser_put(parser); @@ -7321,10 +7331,12 @@ ftrace_graph_release(struct inode *inode, struct file *file) parser = &fgd->parser; + mutex_lock(&parser_lock); if (trace_parser_loaded((parser))) { ret = ftrace_graph_set_hash(fgd->new_hash, parser->buffer); } + mutex_unlock(&parser_lock); trace_parser_put(parser); @@ -7437,6 +7449,7 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, parser = &fgd->parser; + guard(mutex)(&parser_lock); read = trace_get_user(parser, ubuf, cnt, ppos); if (read >= 0 && trace_parser_loaded(parser) &&