Messages in this thread | | | Date | Tue, 24 Jul 2018 22:41:49 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH 1/3] [BUGFIX] tracing: Fix double free of event_trigger_data |
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On Wed, 25 Jul 2018 10:16:53 +0900 Masami Hiramatsu <mhiramat@kernel.org> wrote:
> Hm, as far as I can see, when register_trigger() returns >= 0, it already > calls ->init the trigger_data. This means its refcount++, and in that > case, below patch will miss to free the trigger_data. > How about below for tentative fix? > > if (!ret) { > ret = -ENOENT; > /* We have to forcibly free the trigger_data */ > goto out_free; > } else if (ret > 0) > ret = 0;
Or better yet, match it properly:
out_reg: /* Up the trigger_data count to make sure reg doesn't free it on failure */ event_trigger_init(trigger_ops, trigger_data); ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); /* * The above returns on success the # of functions enabled, * but if it didn't find any functions it returns zero. * Consider no functions a failure too. */ if (!ret) { cmd_ops->unreg(glob, trigger_ops, trigger_data, file); ret = -ENOENT; } else if (ret > 0) ret = 0;
/* Down the counter of trigger_data or free it if not used anymore */ event_trigger_free(trigger_ops, trigger_data); out: return ret;
-- Steve
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