From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D9491C5AD7B for ; Tue, 11 Aug 2026 06:35:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=Rs1yPzUnIco2rjC6CFhLVWVyr0WMS18/eTcbCTT31s8=; b=t/ZB/Jz4v2IGk2tBnIWbHNrJK+ c/qcDhZM5dKpoZcWqWM3892oZtw0H9ntv8z7YjxXQSk2ovYAaKYaGUX13U1QsJ4y/MQdq11hL+n2C H5/p7K9ddZpvVFTaNexbC+xyrW310zaLl0zuACFUQ10h8lZ4WCqJIPJ/J49vZIaUdmGfELT3Oxmyc j1aYcMXLt4Rs1Ff74/8lTBVG5mbEHzxhYnxSL5E2DOYPyjwMWt4WZ4NIE66HsTWJ/efjETRjjDyCh wUosNF3M/MQ2jHjvMiF6tf+epuuCdAOGADLRtFFLW0CiT7o1xb4fSvm5e7+Oi+Z8ovYz6UlbVuTnm ZYIAQduA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wtg4j-0000000DQnP-0cVp; Tue, 11 Aug 2026 06:35:01 +0000 Received: from mail-pl1-x633.google.com ([2607:f8b0:4864:20::633]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wtg4g-0000000DQmi-3lm2 for linux-arm-kernel@lists.infradead.org; Tue, 11 Aug 2026 06:35:00 +0000 Received: by mail-pl1-x633.google.com with SMTP id d9443c01a7336-2d004f135b1so5895245ad.3 for ; Mon, 10 Aug 2026 23:34:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1786430098; x=1787034898; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=Rs1yPzUnIco2rjC6CFhLVWVyr0WMS18/eTcbCTT31s8=; b=UQ4Y60JC7dWCaLSMCYRvda59CS3Ndk8VPBgbv/gPGo+HrIiKAOUq7qCFZyyK/uhY7J 6iPAcRsIj8894XNBumPF2YcIdn18qZX+XQG6p3bRoK5HlsNHAfhTwEB5f41KDztzbm3n ebfb05+NXmADVQmxvAsCXmczf6rGPVBAVEY3mPqZ1tmvWFD3LvpIHxTxMjCrHk+UmkWe NwMwwEB113OjmajWBU8IJ6r8Jhrpz1gBPvTBNFuTlQRTERxE0HzPIvFcndGKQz07lN01 YijmcN/b+ySYRfoJ9/lRV7TIoN7BOoTdK9o2t/6JHAokcaUp86D2VsbXCZL23STkAxBu otXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786430098; x=1787034898; h=content-transfer-encoding:mime-version: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=Rs1yPzUnIco2rjC6CFhLVWVyr0WMS18/eTcbCTT31s8=; b=RaSLm7FL4m83fPoath6M+Mw0AXPGlO1qWblq0dQOx9ZG13qAz6UaqbwbCg685pmVnf iApb0+nWufwmny3ZOyUFb9BIEeXh9RU90V3qQby/xZnNgCGQ8aUZ1FVsCY8AO71PFeXZ qjIWY9zXs5wsCk+Y86VosoU8rTvA2RI8Un8hym2+7kOEB4/14LDnSPzAp7Hj+EJ9ntBR 604xHS5CDnZkaKp9lngB74SMrOaMre+hbLf/MMigHE21f1WSyPVP/RqKCS4imFp47tqP sxf0vFl9W0CNNwFEPG4mE9otQDqyfCeumpsYayAgrrSCi5/WEh95rLu1fTWREAdhIHJi 31Hw== X-Forwarded-Encrypted: i=1; AHgh+RrTZldd4YVtoHTo1qaJToYoBiwU9rLrfBaTsKutFwHF5yAw6v1BfEoXuqDzHy7sXlYfboKqHdTYF7iEZGceQ3ow@lists.infradead.org X-Gm-Message-State: AOJu0YzdjGJxmeCGdoODyT+igbiHDMMeWGhOm9xS8a06//QDGcjCalN3 qafV/g4k+Cj246o/vVjj4ab9bqN57XH50erGNCUgocOolxW8q8WBShjW X-Gm-Gg: AR+sD12eJFKc9+q2eS6sqksnSwLrSoiUOqF8RhAhf9QgP8HqSn851asuXPC21Cvf/+M rqtqHF5bJiLONA6s63FPQXkhVbrQZn64LzHbBCZFSapxOyoGNubSRHNSDYfu4UHjQqf79YJkZhF 4ZF58KgOJrwc4NHips2ru92rJEUwsFurFRDZOJBz/3uHtmGrk5BE86opq3dy6atTpZ+CGI3VQZn Czz+NRw7oPgw2OapDl2By2QDMhGb1KTmtlWruxUP4inxAcKYcUulL+oi2RJ5esrj4vHmug0VWPo 9UVBCFwLSre7Z6bUcNvuNzI4YKBjO0C++sWyDNzk3+0aN7Zel7kS+qpYeRf+qzjbLPacJ97E+Vn vN3IxnHrKOPDGsli1x7uSaXw0yZ2iml7jFEceQWPBNf2tU0rme/EuFl6u3SqNq7urY8+IU6UsrO Y9eQwk4CdSOE2as9XlLEQ8th5KL/20EfO994/RZu2L3YwT/2kOCig= X-Received: by 2002:a17:902:da87:b0:2c6:a772:7e43 with SMTP id d9443c01a7336-2d31798510cmr11974795ad.18.1786430097998; Mon, 10 Aug 2026 23:34:57 -0700 (PDT) Received: from lgs.. ([101.36.106.88]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2d315ef11e8sm2383365ad.1.2026.08.10.23.34.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Aug 2026 23:34:57 -0700 (PDT) From: Guangshuo Li To: Olivia Mackall , Herbert Xu , Maxime Coquelin , Alexandre Torgue , Guangshuo Li , Daniel Thompson , Linus Walleij , linux-crypto@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Subject: [PATCH v2] hwrng: stm32: fix usage_count leak when autosuspend_delay is negative Date: Tue, 11 Aug 2026 14:34:42 +0800 Message-ID: <20260811063442.3058074-1-lgs201920130244@gmail.com> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260810_233459_152170_FCD45F79 X-CRM114-Status: GOOD ( 15.94 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org stm32_rng_probe() calls pm_runtime_use_autosuspend(), but runtime PM is enabled with pm_runtime_enable() and the matching pm_runtime_dont_use_autosuspend() is not called on driver teardown. If the autosuspend delay is set to a negative value while autosuspend is enabled, the runtime PM core increments usage_count to prevent runtime suspend. Without calling pm_runtime_dont_use_autosuspend() during teardown, this reference is not dropped and usage_count remains unbalanced. Use devm_pm_runtime_enable() so that pm_runtime_dont_use_autosuspend() and pm_runtime_disable() are automatically called on probe failure and driver teardown. With runtime PM cleanup handled by devres, stm32_rng_remove() is no longer needed. This issue was found by manual code inspection. Fixes: c6a97c42e399 ("hwrng: stm32 - add support for STM32 HW RNG") Cc: stable@vger.kernel.org Signed-off-by: Guangshuo Li --- v2: - Replace pm_runtime_enable() with devm_pm_runtime_enable() to handle runtime PM cleanup through devres. - Remove stm32_rng_remove() and the manual cleanup on the probe failure path. drivers/char/hw_random/stm32-rng.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c index 9a8c00586ab0..f5bfe54c01dc 100644 --- a/drivers/char/hw_random/stm32-rng.c +++ b/drivers/char/hw_random/stm32-rng.c @@ -368,11 +368,6 @@ static int stm32_rng_init(struct hwrng *rng) return 0; } -static void stm32_rng_remove(struct platform_device *ofdev) -{ - pm_runtime_disable(&ofdev->dev); -} - static int __maybe_unused stm32_rng_runtime_suspend(struct device *dev) { struct stm32_rng_private *priv = dev_get_drvdata(dev); @@ -590,7 +585,9 @@ static int stm32_rng_probe(struct platform_device *ofdev) pm_runtime_set_autosuspend_delay(dev, 100); pm_runtime_use_autosuspend(dev); - pm_runtime_enable(dev); + ret = devm_pm_runtime_enable(dev); + if (ret) + return ret; return devm_hwrng_register(dev, &priv->rng); } @@ -602,7 +599,6 @@ static struct platform_driver stm32_rng_driver = { .of_match_table = stm32_rng_match, }, .probe = stm32_rng_probe, - .remove = stm32_rng_remove, }; module_platform_driver(stm32_rng_driver); -- 2.43.0