From: Josh Poimboeuf <jpoimboe@redhat.com>
To: David Vernet <void@manifault.com>
Cc: pmladek@suse.com, linux-doc@vger.kernel.org,
live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
jikos@kernel.org, mbenes@suse.cz, joe.lawrence@redhat.com,
corbet@lwn.net, yhs@fb.com, songliubraving@fb.com
Subject: Re: [PATCH] livepatch: Fix leak on klp_init_patch_early failure path
Date: Mon, 13 Dec 2021 19:13:10 -0800 [thread overview]
Message-ID: <20211214031310.p6kmbvd73kn6j7x3@treble> (raw)
In-Reply-To: <YbfQHjoUO5GTvImR@dev0025.ash9.facebook.com>
On Mon, Dec 13, 2021 at 02:58:38PM -0800, David Vernet wrote:
> > I don't think the fix will be quite that simple. For example, if
> > klp_init_patch_early() fails, that means try_module_get() hasn't been
> > done, so klp_free_patch_finish() will wrongly do a module_put().
>
> Ugh, good point and thank you for catching that. Another problem with the
> current patch is that we'll call kobject_put() on the patch even if we
> never call kobject_init on the patch due to patch->objs being NULL.
>
> Perhaps we should pull try_module_get() and the NULL check for patch->objs
> out of klp_init_patch_early()? It feels a bit more intuitive to me if
> klp_init_patch_early() were only be responsible for initializing kobjects
> for the patch and its objects / funcs anyways.
>
> Testing it locally seems to work fine. Let me know if this sounds
> reasonable to you, and I'll send out a v2 patch with the fixes to both the
> patch description, and logic.
Sounds reasonable to me. Thanks.
--
Josh
next prev parent reply other threads:[~2021-12-14 3:13 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-13 19:17 [PATCH] livepatch: Fix leak on klp_init_patch_early failure path David Vernet
2021-12-13 20:10 ` Josh Poimboeuf
2021-12-13 22:58 ` David Vernet
2021-12-13 23:32 ` Song Liu
2021-12-14 3:13 ` Josh Poimboeuf [this message]
2021-12-14 8:45 ` Petr Mladek
2021-12-14 9:17 ` Miroslav Benes
2021-12-14 15:26 ` David Vernet
2021-12-14 15:50 ` Greg Kroah-Hartman
2021-12-15 8:19 ` Petr Mladek
2021-12-15 15:35 ` Greg Kroah-Hartman
2021-12-16 14:14 ` Petr Mladek
2021-12-16 14:35 ` Greg Kroah-Hartman
2021-12-17 13:10 ` Petr Mladek
2021-12-16 15:14 ` David Vernet
2021-12-17 13:53 ` Petr Mladek
2021-12-15 8:33 ` Miroslav Benes
2021-12-14 15:52 ` Greg Kroah-Hartman
2021-12-14 18:26 ` David Vernet
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