Messages in this thread | | | Subject | Re: [PATCH] regulator: of: Add of_node_put() before return in function | From | Nishka Dasgupta <> | Date | Wed, 31 Jul 2019 18:41:03 +0530 |
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On 26/07/19 4:15 PM, Mark Brown wrote: > On Fri, Jul 26, 2019 at 01:02:52PM +0530, Nishka Dasgupta wrote: >> On 24/07/19 9:17 PM, Mark Brown wrote: >>> On Wed, Jul 24, 2019 at 02:02:31PM +0530, Nishka Dasgupta wrote: > >>>> The local variable search in regulator_of_get_init_node takes the value >>>> returned by either of_get_child_by_name or of_node_get, both of which >>>> get a node. If this node is not put before returning, it could cause a >>>> memory leak. Hence put search before a mid-loop return statement. >>>> Issue found with Coccinelle. > >>>> - if (!strcmp(desc->of_match, name)) >>>> + if (!strcmp(desc->of_match, name)) { >>>> + of_node_put(search); >>>> return of_node_get(child); >>>> + } > >>> Why not just remove the extra of_node_get() and a comment explaining why >>> it's not needed? > >> I'm sorry, I don't think I understand. I'm putting search in this patch; the >> program was already getting child. Should I also return child directly >> instead of getting it again, and continue to put search? > > Your new code is dropping a reference then immediately reacquiring one > to return it (introducing a race condition along the way). Why not just > return the already held reference and not call any functions at all? > I still don't understand. Previously the function was acquiring a reference to child with of_node_get(). My added code is dropping a reference to search, using of_node_put(). I'm probably misunderstanding this at some point, but I thought search and child are two different nodes? Or am I completely misunderstanding what you're explaining? Apologies for the confusion.
Thanking you, Nishka
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