From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B3D8135C1A0; Wed, 20 May 2026 17:18:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779297538; cv=none; b=ok+SEAyf/ipBRUdm7C6SOldnAT59LibCV4ET4Bo+buzThRtk/JF7/9pGZ49+TcGpofQsZ10HpLNuqExMiwDd7hs58DxUaJ01ycUdD2lF9Z51InP6m6aOFCXIx8DTZa7cw8NSGLQRY5RHWxyaU4HDFey/Z7gtD8Zk/nxMTO47ksw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779297538; c=relaxed/simple; bh=pVcq1nDvtkvNK+1fih0BtQRZOt5/YkneZ0GCp2y/PvQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sft/Qrul4ME9JlVrmOwi+3BYm85RbZLDos1ubRw7QX5LVRQUTXc1sRdAJGFY3316FBWyAa9eqOviqlIdPN1Sa+g6Ly81EUR6iKglZDhgmjxdYOnobD6izyx6pLXgjQlcX1it6OCgqxpvTrjtGb6GLo6S/c0XfzO9/gwMAxi8QPc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yPYtaRSI; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="yPYtaRSI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26FD51F000E9; Wed, 20 May 2026 17:18:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779297537; bh=AO8MQOYjIr0chSIigcyx2kVLgZhkDKeBvaokTVNAb3w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=yPYtaRSI4XRAsV9h8DYrWp3Z0+o+5OHNeikFW9q14gGYi9FvXUky/0eAC26zGwnMR BoZWBNSBBUMob91nKkcS+N6byEaR7XijGC0kJU+8OBuKfV1/I9SF//LdXAwvlRX1Wl /jgUZ6tKjapTCSb2HKWtEZ/JClCMN0XwDeMRDr3g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Petr Pavlu , Sami Tolvanen , Sasha Levin Subject: [PATCH 6.18 068/957] module: Fix freeing of charp module parameters when CONFIG_SYSFS=n Date: Wed, 20 May 2026 18:09:11 +0200 Message-ID: <20260520162136.039373598@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162134.554764788@linuxfoundation.org> References: <20260520162134.554764788@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Petr Pavlu [ Upstream commit deffe1edba626d474fef38007c03646ca5876a0e ] When setting a charp module parameter, the param_set_charp() function allocates memory to store a copy of the input value. Later, when the module is potentially unloaded, the destroy_params() function is called to free this allocated memory. However, destroy_params() is available only when CONFIG_SYSFS=y, otherwise only a dummy variant is present. In the unlikely case that the kernel is configured with CONFIG_MODULES=y and CONFIG_SYSFS=n, this results in a memory leak of charp values when a module is unloaded. Fix this issue by making destroy_params() always available when CONFIG_MODULES=y. Rename the function to module_destroy_params() to clarify that it is intended for use by the module loader. Fixes: e180a6b7759a ("param: fix charp parameters set via sysfs") Signed-off-by: Petr Pavlu Signed-off-by: Sami Tolvanen Signed-off-by: Sasha Levin --- include/linux/moduleparam.h | 11 +++-------- kernel/module/main.c | 4 ++-- kernel/params.c | 27 ++++++++++++++++++--------- 3 files changed, 23 insertions(+), 19 deletions(-) diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 6907aedc4f748..77775fd821407 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -414,14 +414,9 @@ extern char *parse_args(const char *name, void *arg, parse_unknown_fn unknown); /* Called by module remove. */ -#ifdef CONFIG_SYSFS -extern void destroy_params(const struct kernel_param *params, unsigned num); -#else -static inline void destroy_params(const struct kernel_param *params, - unsigned num) -{ -} -#endif /* !CONFIG_SYSFS */ +#ifdef CONFIG_MODULES +void module_destroy_params(const struct kernel_param *params, unsigned int num); +#endif /* All the helper functions */ /* The macros to do compile-time type checking stolen from Jakub diff --git a/kernel/module/main.c b/kernel/module/main.c index 66d4efbddfffe..3745cd02c8479 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -1408,7 +1408,7 @@ static void free_module(struct module *mod) module_unload_free(mod); /* Free any allocated parameters. */ - destroy_params(mod->kp, mod->num_kp); + module_destroy_params(mod->kp, mod->num_kp); if (is_livepatch_module(mod)) free_module_elf(mod); @@ -3519,7 +3519,7 @@ static int load_module(struct load_info *info, const char __user *uargs, mod_sysfs_teardown(mod); coming_cleanup: mod->state = MODULE_STATE_GOING; - destroy_params(mod->kp, mod->num_kp); + module_destroy_params(mod->kp, mod->num_kp); blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); klp_module_going(mod); diff --git a/kernel/params.c b/kernel/params.c index 7c2242f64bf08..8942884e21c43 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -746,15 +746,6 @@ void module_param_sysfs_remove(struct module *mod) } #endif -void destroy_params(const struct kernel_param *params, unsigned num) -{ - unsigned int i; - - for (i = 0; i < num; i++) - if (params[i].ops->free) - params[i].ops->free(params[i].arg); -} - struct module_kobject * __init_or_module lookup_or_create_module_kobject(const char *name) { @@ -986,3 +977,21 @@ static int __init param_sysfs_builtin_init(void) late_initcall(param_sysfs_builtin_init); #endif /* CONFIG_SYSFS */ + +#ifdef CONFIG_MODULES + +/* + * module_destroy_params - free all parameters for one module + * @params: module parameters (array) + * @num: number of module parameters + */ +void module_destroy_params(const struct kernel_param *params, unsigned int num) +{ + unsigned int i; + + for (i = 0; i < num; i++) + if (params[i].ops->free) + params[i].ops->free(params[i].arg); +} + +#endif /* CONFIG_MODULES */ -- 2.53.0