From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A6B7D1A2632; Tue, 17 Jun 2025 16:22:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750177379; cv=none; b=jFmEDxEWxmeIeDRI5df295XZnQvVg1y48xLK+4C50AxqhRM556u4FDo+WpK7RwSxNYGvxM1wbq170Jd/ixda79rdXtzgB6E9wC7Epi8pN3pKm9VTbQqgzLzpGV91C6a/drYTQ5o/OTXz9iCaBEp8lZJAoeiaR0xfPvALpxSA6u8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750177379; c=relaxed/simple; bh=w4xx/HJ0JDXO69E8o3tqEvWhgt6iYb0YLEfQuwhDkwQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kqWJVyz6pXqsA0fxGvScCtbZfFQ1//wx3AabmEE6djDYQY5SFJNRftEuyFsZ49AEYKe8RPDnwAUWNxPCEPKGojWHEYijgiHp4eOdCYlyHLPesw+sXJGkaAVZGiq836snZ0UvbqQO4AU2Fd91BncC4IJcvIZ7DGbb/yrK99beX9k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XCFSarRH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="XCFSarRH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15692C4CEE3; Tue, 17 Jun 2025 16:22:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750177379; bh=w4xx/HJ0JDXO69E8o3tqEvWhgt6iYb0YLEfQuwhDkwQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XCFSarRHNwDZ5PTnD+l99aLBbfyUtCqCZBZfrzQRKj4FMVqgX8mG9Zh1eNKCxiQjU ScETmO0SVhGlNJgap/y1JJ5UHcCO6u2xOencvGdG3oSaFTK95b//vQJqzlQfW2jdJg Hu0aj89BLYz+t+5kxxWqnJnDyOZhleGSpjL+kx0A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Suzuki K Poulose , Yeoreum Yun , Leo Yan , Sasha Levin Subject: [PATCH 6.12 335/512] coresight: prevent deactivate active config while enabling the config Date: Tue, 17 Jun 2025 17:25:01 +0200 Message-ID: <20250617152433.188175263@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250617152419.512865572@linuxfoundation.org> References: <20250617152419.512865572@linuxfoundation.org> User-Agent: quilt/0.68 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yeoreum Yun [ Upstream commit 408c97c4a5e0b634dcd15bf8b8808b382e888164 ] While enable active config via cscfg_csdev_enable_active_config(), active config could be deactivated via configfs' sysfs interface. This could make UAF issue in below scenario: CPU0 CPU1 (sysfs enable) load module cscfg_load_config_sets() activate config. // sysfs (sys_active_cnt == 1) ... cscfg_csdev_enable_active_config() lock(csdev->cscfg_csdev_lock) // here load config activate by CPU1 unlock(csdev->cscfg_csdev_lock) deactivate config // sysfs (sys_activec_cnt == 0) cscfg_unload_config_sets() unload module // access to config_desc which freed // while unloading module. cscfg_csdev_enable_config To address this, use cscfg_config_desc's active_cnt as a reference count which will be holded when - activate the config. - enable the activated config. and put the module reference when config_active_cnt == 0. Fixes: f8cce2ff3c04 ("coresight: syscfg: Add API to activate and enable configurations") Suggested-by: Suzuki K Poulose Signed-off-by: Yeoreum Yun Reviewed-by: Leo Yan Signed-off-by: Suzuki K Poulose Link: https://lore.kernel.org/r/20250514161951.3427590-4-yeoreum.yun@arm.com Signed-off-by: Sasha Levin --- .../hwtracing/coresight/coresight-config.h | 2 +- .../hwtracing/coresight/coresight-syscfg.c | 49 +++++++++++++------ 2 files changed, 35 insertions(+), 16 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h index 6ba0139757418..84cdde6f0e4db 100644 --- a/drivers/hwtracing/coresight/coresight-config.h +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -228,7 +228,7 @@ struct cscfg_feature_csdev { * @feats_csdev:references to the device features to enable. */ struct cscfg_config_csdev { - const struct cscfg_config_desc *config_desc; + struct cscfg_config_desc *config_desc; struct coresight_device *csdev; bool enabled; struct list_head node; diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index 11138a9762b01..30a561d874819 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -867,6 +867,25 @@ void cscfg_csdev_reset_feats(struct coresight_device *csdev) } EXPORT_SYMBOL_GPL(cscfg_csdev_reset_feats); +static bool cscfg_config_desc_get(struct cscfg_config_desc *config_desc) +{ + if (!atomic_fetch_inc(&config_desc->active_cnt)) { + /* must ensure that config cannot be unloaded in use */ + if (unlikely(cscfg_owner_get(config_desc->load_owner))) { + atomic_dec(&config_desc->active_cnt); + return false; + } + } + + return true; +} + +static void cscfg_config_desc_put(struct cscfg_config_desc *config_desc) +{ + if (!atomic_dec_return(&config_desc->active_cnt)) + cscfg_owner_put(config_desc->load_owner); +} + /* * This activate configuration for either perf or sysfs. Perf can have multiple * active configs, selected per event, sysfs is limited to one. @@ -890,22 +909,17 @@ static int _cscfg_activate_config(unsigned long cfg_hash) if (config_desc->available == false) return -EBUSY; - /* must ensure that config cannot be unloaded in use */ - err = cscfg_owner_get(config_desc->load_owner); - if (err) + if (!cscfg_config_desc_get(config_desc)) { + err = -EINVAL; break; + } + /* * increment the global active count - control changes to * active configurations */ atomic_inc(&cscfg_mgr->sys_active_cnt); - /* - * mark the descriptor as active so enable config on a - * device instance will use it - */ - atomic_inc(&config_desc->active_cnt); - err = 0; dev_dbg(cscfg_device(), "Activate config %s.\n", config_desc->name); break; @@ -920,9 +934,8 @@ static void _cscfg_deactivate_config(unsigned long cfg_hash) list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) { if ((unsigned long)config_desc->event_ea->var == cfg_hash) { - atomic_dec(&config_desc->active_cnt); atomic_dec(&cscfg_mgr->sys_active_cnt); - cscfg_owner_put(config_desc->load_owner); + cscfg_config_desc_put(config_desc); dev_dbg(cscfg_device(), "Deactivate config %s.\n", config_desc->name); break; } @@ -1047,7 +1060,7 @@ int cscfg_csdev_enable_active_config(struct coresight_device *csdev, unsigned long cfg_hash, int preset) { struct cscfg_config_csdev *config_csdev_active = NULL, *config_csdev_item; - const struct cscfg_config_desc *config_desc; + struct cscfg_config_desc *config_desc; unsigned long flags; int err = 0; @@ -1062,8 +1075,8 @@ int cscfg_csdev_enable_active_config(struct coresight_device *csdev, spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); list_for_each_entry(config_csdev_item, &csdev->config_csdev_list, node) { config_desc = config_csdev_item->config_desc; - if ((atomic_read(&config_desc->active_cnt)) && - ((unsigned long)config_desc->event_ea->var == cfg_hash)) { + if (((unsigned long)config_desc->event_ea->var == cfg_hash) && + cscfg_config_desc_get(config_desc)) { config_csdev_active = config_csdev_item; csdev->active_cscfg_ctxt = (void *)config_csdev_active; break; @@ -1097,7 +1110,11 @@ int cscfg_csdev_enable_active_config(struct coresight_device *csdev, err = -EBUSY; spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); } + + if (err) + cscfg_config_desc_put(config_desc); } + return err; } EXPORT_SYMBOL_GPL(cscfg_csdev_enable_active_config); @@ -1136,8 +1153,10 @@ void cscfg_csdev_disable_active_config(struct coresight_device *csdev) spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); /* true if there was an enabled active config */ - if (config_csdev) + if (config_csdev) { cscfg_csdev_disable_config(config_csdev); + cscfg_config_desc_put(config_csdev->config_desc); + } } EXPORT_SYMBOL_GPL(cscfg_csdev_disable_active_config); -- 2.39.5