From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 760485328AA for ; Tue, 8 Sep 2026 12:04:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788869085; cv=none; b=ALFYUc4VjqChwaKDx4ztDp9j84E2LXW4LeLRvUi1sa2KHEgF+fk+cQrIRHOzpPOnbVXfWaHCJL917Gim7vBjul2UtDtt41SirpcQNMGIFOsjfr7gqCzy1cx6qcgHj8K0k0TjuM82JDj5Yrl5DRJJQMZnyjRv8ApTrigWPsJ3l0s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788869085; c=relaxed/simple; bh=DVuuPUwXLwtT0Ymk60JQVhNGfMYWdFufX5xFsm2SN0Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hxhT9GEKmdUUPjMqThyRtRnX4H7kIScc6JvGp0U/k2x/JVQ4RUe0YuT2j4HjIEJNKC75d16oyEHam5I8ErJgyvwz/Jb9atsZoBfCMZzLOcguzYpa91Gc6Rz0dbok+GTvWNtAxYz9LLT+VTFFeQ+DgG8Qd37vPI2qRkUDH82J7P4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=AE4oPbrB; arc=none smtp.client-ip=209.85.128.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="AE4oPbrB" Received: by mail-wm1-f53.google.com with SMTP id 5b1f17b1804b1-49b8eeb3ff2so42947195e9.2 for ; Tue, 08 Sep 2026 05:04:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1788869078; x=1789473878; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=FWdRM8KWaj2QeHMO2XI9aeMbB/7rTG7L5o5/mygY1k4=; b=AE4oPbrBXiKJIGNuH5An6h8EXwLlG/v3FDNKEj55VhC7ysk+7ZEJqfOqjoXXHN5YmF fo0Vpxb7sTdPzjwxttrscfAp1Yz8L7L9BRyaz9WctV1r1u00meHO4OJZ34/+NEBl080k CBYaDmwESAQlBDNINM7DDBwVJvq4VOa+p4FkNoihjf/KZI2KeTMXVH9NUKRzAxMFpEg6 in1hSy8hfGpK/YweQJe1IPkUBdCMhMwwmEvRHw9WEMK+eRqmDkGyMiMptuwO+c4lrrry qdDCFO8/jUQSbRk1FgKIFFpTByhMI6/JQpTG9fv73GyAb9p4Q4mph5rBe+gA0cMNaVa4 HLuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788869078; x=1789473878; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=FWdRM8KWaj2QeHMO2XI9aeMbB/7rTG7L5o5/mygY1k4=; b=ZkMH0pi5M+qOH77ccU9RXB5FHslypTxB4nhWyvOKJg445hUdZ5Qwez1FigifhQo+Z3 RfzX+yQlaVo0q/p9FpAFcxGoLPk4CKgKOJd4p5sLAs2gqGCNWv74jkzdAFuzZdTg3u7c DGHzGbQfi8FCYcWvQCc5OwRukk+sLYzcZjEIQovWxnwQ8YwcqiLhInBFqAOkc2foLnas VTGmBhF8CwUk/NNGjnQRwUAJGQwYG868LBlnCnoYazDs5R4JfvRDkjFxS2HaRFumcTtx EN+HggpN+OY1klfGY5cHj4eLihfmGIHfODZBwPTmhwlhmXObuzdMRnHkjnZIqKnTDv7a T5nQ== X-Forwarded-Encrypted: i=1; AKwUvBwJCaYYVN9QsUrVNoxsaiJlNxdbBzbXXfF2B9SjSEPCeidedC0cKj7NIax14F4/XpE4WnwQdzt3tC2nk01q@vger.kernel.org X-Gm-Message-State: AFuF++kURrPnQf+qAPDWyCnmc3dKEErdGYuFJE23Z4IM8YFGuNkh8px1 uRSW7wms4DIY6rwPGqe7q9xiW/ALZwnvp8j0m8e+/3hNJXboA4zCHddBGWB1RyIUKLg= X-Gm-Gg: AYBFou1UVufr5eEK1KtX+wTIT/MoQ91jZUvuv4DR/1SyPtu0gaUY7Ke26aZTyq1q85W /wfafftbj5zDrekpwVnQnLdUhG02dmHMMDXRVe/47twGCKfpPCsrPoEt878mhgEqUTCxUCrBh+j aeIOWikug3czJk/T5BaacCB7h77+DWeMo4UKdcPmIm/lQyMr/dwa401VJbFR/lVDGzN/DZp9k6b mopk+JPfBmyJz7j/OO3ozR7rlQbO99ufu7ioWiZBHl3gHYzXetW8gpXc1oS2CyPYnrBnJYlOLAO BWtOvdl9XwpYb/ZV6C1N+O/16txaFg4bt32A63ln9CWcSVZDW6UdyOThqFpB81p6BqktXXsLf0i ZWnW2GOmek2oE4MrVSrPXfq+SpHZTGh6kxtHMOfOHbOQpegs1jxTQa8ual0oK3g7NiwSyY/o1wW nVMBvZg5ZuaYsjuHq1dFwQrpImLb+hdaFDVBuZrTWVxnbGDIPi4FA= X-Received: by 2002:a05:600c:3b01:b0:49c:fa21:e73b with SMTP id 5b1f17b1804b1-49cfa21e86cmr239776125e9.17.1788869078416; Tue, 08 Sep 2026 05:04:38 -0700 (PDT) Received: from pathway ([176.114.240.130]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-485885b7bfasm36371435f8f.29.2026.09.08.05.04.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Sep 2026 05:04:36 -0700 (PDT) From: Petr Mladek To: Harry Hsu , jpoimboe@kernel.org, mbenes@suse.cz, joe.lawrence@redhat.com Cc: jikos@kernel.org, live-patching@vger.kernel.org, shuah@kernel.org, song@kernel.org, linux-kernel@vger.kernel.org, Petr Mladek , sashiko-bot@kernel.org Subject: [PATCH v4 5/5] livepatch: Clean up klp_init_object_loaded() when fails Date: Tue, 8 Sep 2026 14:03:25 +0200 Message-ID: <20260908120325.299649-6-pmladek@suse.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260908120325.299649-1-pmladek@suse.com> References: <20260908120325.299649-1-pmladek@suse.com> Precedence: bulk X-Mailing-List: live-patching@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit When loading a module, klp_module_coming() updates all enabled patches. If an error occurs, klp_cleanup_module_patches_limited() cleans up fully processed patches, but skips the patch that failed midway. The current code is a bit messy. The changes done by klp_init_object_loaded() should get cleared by klp_free_object_loaded(). But this function also clears obj->mod which is set by klp_module_coming(). And relocations are cleared separately. Fix the situations by updating klp_free_object_loaded(). It should revert all and only changes made by klp_init_object_loaded(). This requires some shuffling: + Clear obj->mod explicitly in klp_cleanup_module_patches_limited() and do not rely on klp_free_object_loaded(). + Clear relocations in klp_free_object_loaded(). Remove the explicit call from klp_cleanup_module_patches_limited(). This requires adding the @patch parameter. Next, klp_init_object_loaded() has to clear its own changes on failure. It just returns an error when relocations failed because they clear their own mess. It could call klp_free_object_loaded() in other situations because all relocations were done and other values are just cleared. Finally, in klp_module_coming(), avoid code duplication by goto targets. There is no need to clear relocations for other objects in the failing patch because klp_module_coming() operates strictly on the specific module being loaded. Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/r/20260823062313.1321B1F000E9@smtp.kernel.org Closes: https://lore.kernel.org/r/20260830175608.4BABB1F000E9@smtp.kernel.org Acked-by: Song Liu Signed-off-by: Petr Mladek --- kernel/livepatch/core.c | 37 +++++++++++++++++++++++++------------ 1 file changed, 25 insertions(+), 12 deletions(-) diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 714f97fdd271..87b2331486d4 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -738,18 +738,20 @@ static void __klp_free_funcs(struct klp_object *obj, bool nops_only) } /* Clean up when a patched object is unloaded */ -static void klp_free_object_loaded(struct klp_object *obj) +static void klp_free_object_loaded(struct klp_patch *patch, + struct klp_object *obj) { struct klp_func *func; - obj->mod = NULL; - klp_for_each_func(obj, func) { func->old_func = NULL; if (func->nop) func->new_func = NULL; } + + if (klp_is_module(obj)) + klp_clear_object_relocs(patch, obj); } static void __klp_free_objects(struct klp_patch *patch, bool nops_only) @@ -896,7 +898,7 @@ static int klp_init_object_loaded(struct klp_patch *patch, func->old_sympos, (unsigned long *)&func->old_func); if (ret) - return ret; + goto err; /* * Aliased symbols share one address, so they would resolve to @@ -909,7 +911,8 @@ static int klp_init_object_loaded(struct klp_patch *patch, if (prev_func->old_func == func->old_func) { pr_err("'%s' and '%s' resolve to the same address, aliased symbols are not supported\n", prev_func->old_name, func->old_name); - return -EINVAL; + ret = -EINVAL; + goto err; } } @@ -918,7 +921,8 @@ static int klp_init_object_loaded(struct klp_patch *patch, if (!ret) { pr_err("kallsyms size lookup failed for '%s'\n", func->old_name); - return -ENOENT; + ret = -ENOENT; + goto err; } if (func->nop) @@ -929,11 +933,17 @@ static int klp_init_object_loaded(struct klp_patch *patch, if (!ret) { pr_err("kallsyms size lookup failed for '%s' replacement\n", func->old_name); - return -ENOENT; + ret = -ENOENT; + goto err; } } return 0; + +err: + klp_free_object_loaded(patch, obj); + + return ret; } static int klp_init_object(struct klp_patch *patch, struct klp_object *obj) @@ -1287,8 +1297,8 @@ static void klp_cleanup_module_patches_limited(struct module *mod, klp_unpatch_object(obj); klp_post_unpatch_callback(obj); - klp_clear_object_relocs(patch, obj); - klp_free_object_loaded(obj); + klp_free_object_loaded(patch, obj); + obj->mod = NULL; break; } } @@ -1337,7 +1347,7 @@ int klp_module_coming(struct module *mod) if (ret) { pr_warn("pre-patch callback failed for object '%s'\n", obj->name); - goto err; + goto err_free_object; } ret = klp_patch_object(obj); @@ -1345,8 +1355,7 @@ int klp_module_coming(struct module *mod) pr_warn("failed to apply patch '%s' to module '%s' (%d)\n", patch->mod->name, obj->mod->name, ret); - klp_post_unpatch_callback(obj); - goto err; + goto err_unpatch_callback; } if (patch != klp_transition_patch) @@ -1360,6 +1369,10 @@ int klp_module_coming(struct module *mod) return 0; +err_unpatch_callback: + klp_post_unpatch_callback(obj); +err_free_object: + klp_free_object_loaded(patch, obj); err: /* * If a patch is unsuccessfully applied, return -- 2.55.0