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From: Daniel Gomez <da.gomez@kernel.org>
To: Petr Pavlu <petr.pavlu@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>,
	Sami Tolvanen <samitolvanen@google.com>,
	Daniel Gomez <da.gomez@samsung.com>,
	linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] module: Fix memory deallocation on error path in move_module()
Date: Sat, 14 Jun 2025 23:28:12 +0200	[thread overview]
Message-ID: <7cf40cd1-fe0d-4493-ac15-e70c418e54a5@kernel.org> (raw)
In-Reply-To: <c7dbb33d-98b6-45da-be77-e86b9e6787ee@suse.com>

> This seems to be off by one. For instance, if the loop reaches the last
> valid type in mod_mem_type, MOD_INIT_RODATA, and successfully allocates
> its memory, the variable t gets set to MOD_INIT_RODATA. Subsequently, if
> an error occurs later in move_module() and control is transferred to
> out_err, the deallocation starts from t-1, and therefore MOD_INIT_RODATA
> doesn't get freed.
> 
> If we want to always start from the last type found, the code would need
> to be:
> 
> 		[...]
> 		ret = module_memory_alloc(mod, type);
> 		if (ret)
> 			goto out_err;
> 		t = type + 1;
> 	}
> 
> I can adjust it in this way if it is preferred.
> 

My earlier suggestion was incorrect. We can simply initialize the memory
type t to MOD_MEM_NUM_TYPES since it's only used in the error path of
module_memory_alloc().

  reply	other threads:[~2025-06-14 21:28 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-07 16:16 [PATCH 0/2] " Petr Pavlu
2025-06-07 16:16 ` [PATCH 1/2] " Petr Pavlu
2025-06-08  7:25   ` Petr Pavlu
2025-06-09 22:12     ` Sami Tolvanen
2025-06-10 18:51   ` Daniel Gomez
2025-06-12 10:48     ` Petr Pavlu
2025-06-14 21:28       ` Daniel Gomez [this message]
2025-06-16 13:58         ` Petr Pavlu
2025-06-17  9:47           ` Daniel Gomez
2025-06-17 15:41             ` Petr Pavlu
2025-06-17 17:17               ` Daniel Gomez
2025-06-07 16:16 ` [PATCH 2/2] module: Avoid unnecessary return value initialization " Petr Pavlu
2025-06-09 22:13   ` Sami Tolvanen
2025-06-10 18:56   ` Daniel Gomez

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