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 D80BE3BC4F3; Thu, 15 Jan 2026 17:10:03 +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=1768497003; cv=none; b=TzWWG5h+bMHOWfQHPLeI0YNO+/KtmFfmAmqlS2wLGMyTxTwry+TTKY1GCWuqv9e14idsGRlHmeUdReJ4+7PIx6UZil4xSBWs1wyzhmCnhi8KOXkI0HGqAIozuNtjN/8GIAlq9w2c/CsYYmjoknYaHXRqF+KSLGrYh/Q87SzTFlE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768497003; c=relaxed/simple; bh=+oHcCJktbvUfyy9qFibH8jMt6QcsfTUxPA+h8n1qjYI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NNA4sltc6F9i5tGLzQwYcxWL34h2rMNqc/8aE6XQGbgyIxbjUT/T1BzNlOHLTpZFmj/8pW5L+hRDWZQ6eOu+YupHQ4UwiCiUHGm/G3kehHVeY8Awa0gM/ztbc6C9sebyUgUVlRk52svI5um3wyKbHiqCix8fkl9cbSV/M0XbvbE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=A/+1qFAI; 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="A/+1qFAI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61AE6C116D0; Thu, 15 Jan 2026 17:10:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1768497003; bh=+oHcCJktbvUfyy9qFibH8jMt6QcsfTUxPA+h8n1qjYI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A/+1qFAI94Fs1sJJrekwPuQkpub/jhi1YqvqMxuT5wZz1QfNNdhjdlHoFXtEXv+y1 yp3sgvAldxQtSwEthPpoJwhowgeCJjB5DLgcKB9R799xCDy4DmYGPvqC7jG09Y2R0D 3RMFtr9P0wItRBDzWzl0QwBxWQUAKV9tQ2IjnvT8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sumeet Pawnikar , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 6.6 78/88] powercap: fix race condition in register_control_type() Date: Thu, 15 Jan 2026 17:49:01 +0100 Message-ID: <20260115164149.140295597@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260115164146.312481509@linuxfoundation.org> References: <20260115164146.312481509@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sumeet Pawnikar [ Upstream commit 7bda1910c4bccd4b8d4726620bb3d6bbfb62286e ] The device becomes visible to userspace via device_register() even before it fully initialized by idr_init(). If userspace or another thread tries to register a zone immediately after device_register(), the control_type_valid() will fail because the control_type is not yet in the list. The IDR is not yet initialized, so this race condition causes zone registration failure. Move idr_init() and list addition before device_register() fix the race condition. Signed-off-by: Sumeet Pawnikar [ rjw: Subject adjustment, empty line added ] Link: https://patch.msgid.link/20251205190216.5032-1-sumeet4linux@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/powercap/powercap_sys.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/powercap/powercap_sys.c b/drivers/powercap/powercap_sys.c index 4112a00973382..d14b36b75189d 100644 --- a/drivers/powercap/powercap_sys.c +++ b/drivers/powercap/powercap_sys.c @@ -625,17 +625,23 @@ struct powercap_control_type *powercap_register_control_type( INIT_LIST_HEAD(&control_type->node); control_type->dev.class = &powercap_class; dev_set_name(&control_type->dev, "%s", name); - result = device_register(&control_type->dev); - if (result) { - put_device(&control_type->dev); - return ERR_PTR(result); - } idr_init(&control_type->idr); mutex_lock(&powercap_cntrl_list_lock); list_add_tail(&control_type->node, &powercap_cntrl_list); mutex_unlock(&powercap_cntrl_list_lock); + result = device_register(&control_type->dev); + if (result) { + mutex_lock(&powercap_cntrl_list_lock); + list_del(&control_type->node); + mutex_unlock(&powercap_cntrl_list_lock); + + idr_destroy(&control_type->idr); + put_device(&control_type->dev); + return ERR_PTR(result); + } + return control_type; } EXPORT_SYMBOL_GPL(powercap_register_control_type); -- 2.51.0