linux-kernel - Re: [PATCH 1/2] module: Fix memory deallocation on error path in move

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Message-ID: <bae6e1f3-efbc-47d9-8eb4-653f851311d7@kernel.org>
Date: Tue, 17 Jun 2025 19:17:32 +0200
From: Daniel Gomez <da.gomez@...nel.org>
To: Petr Pavlu <petr.pavlu@...e.com>
Cc: Luis Chamberlain <mcgrof@...nel.org>,
 Sami Tolvanen <samitolvanen@...gle.com>, Daniel Gomez
 <da.gomez@...sung.com>, linux-modules@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] module: Fix memory deallocation on error path in
 move_module()



>> One thing though, we are "releasing" the memory even if we have skipped the
>> allocation in the first place. So, I think it would make sense to release only
>> for the types we have actually allocated. What do you think?
> 
> I noticed this too, specifically because move_module() is inconsistent
> in this regard with free_mod_mem(). The latter function contains:
> 
> if (mod_mem->size)
> 	module_memory_free(mod, type);
> 
> However, my preference is actually to update free_mod_mem() and remove
> the check. The function module_memory_free() should be a no-op if
> mod->base is NULL, similarly to how calling free(NULL) is a no-op.
> 

Sound good to me. Perhaps a different patch type for cleanup/refactor. The fix
here would be back-ported to stable branches. So these are 2 different things.