From nobody Wed Dec 17 04:16:46 2025 Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) (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 A500F2DF719 for ; Fri, 5 Dec 2025 19:02:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.53 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764961347; cv=none; b=AzwNDMIJtlUaufxE9of855eLQjAo0TGkjQMDbnprjnxIkKA3lW5yiZ9aZE4+nzg67yVawoJa19uTiZ3Ob2g4ync3EOYjEXgWA8+byuE9K21dtoUTA4M0uZsZj6uVI5CYww40LXFObg8dBPSRgr03JPFSPHcDs6gb+GBWJa3c7qY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764961347; c=relaxed/simple; bh=BZ40Qr+VCK0a19X541gPydfySH8VknjOkzRAW0odqYE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=I/D0hks9uvpurFMdf3N1YvAFfh86JlkStaoJh/oN36MtNoFZ44aqRmKcLibDKgli14gW+R8+u/qfo2ZTwEdCHi9IMwSAfwgBXDv7APytEOnyhIiEITyBRWaqSaRt7SlF8xLSs0v30szKgIVH3inuuiyeRguHdXt6j6vw5VW/3oc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=c5DzquLf; arc=none smtp.client-ip=209.85.216.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="c5DzquLf" Received: by mail-pj1-f53.google.com with SMTP id 98e67ed59e1d1-3434700be69so3462186a91.1 for ; Fri, 05 Dec 2025 11:02:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1764961345; x=1765566145; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=UVgkDGLlp+gBx2zQWaI190FEJKwlN+nT2HtV4xsm0D8=; b=c5DzquLf1OB+N9rmAFgTdcrBh0MQR7Hq7NXNY7k1QVA/Y1O27pgcNnr1ucgQ9cPdqK ydLRzdJJtCZ0ITHoP3UjCarpwTTZ5T3As7grYnC3/zuzyMEc/V6Ew3x+aNgmxXXLyIBG pZmJm+Ia2kOxwF34nfzokq4gIweyb2TyHYJfOeIlo+opZJLlYxoKPEOEqI37tlj/tkqe f538J6OK/Kh0Ek8p5Lqsx3STfNk/m8pVPPe2/Tla1WiPCtg/N2EOljR/WPg0vUkmPaYL h4n4jcqtioXzc3/Uc8gKEZe0yfngnynvMHfqRzBnS7ojo8vOmOoWwfMoOMbUS9HUYGeM s5tA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764961345; x=1765566145; 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; bh=UVgkDGLlp+gBx2zQWaI190FEJKwlN+nT2HtV4xsm0D8=; b=Wv0vkEsR01Nm2XKWw7xqdbHa0ijZxMgSJ8c2ZDMIuID94S7A65gICzZPPmTKEct5Ze ptWhQ5KUDqhX90EY1X9RT7GuO/JG4NYvnvRGXck8gTlBvhgOy2Okfs287f+t05kqx/NG mAGOM+avZLCplv0/6fAVLSMd9Da3MN+eRWcCXiHju9QLj3/4zDx6WF43RZL1mgQYuU+7 pGA4opGGQ3GVbTFpKxumoTtUY/rPH5ulAsmxIRL/U6rYyQlXLeU3IdcK62t72FW6clkN IzsG33apftR2kxDFi5QbQfeIhqwgyNLPvZZfJyZOT9VsLDyxhsKEo9rwsoscaU70mLO4 kyww== X-Gm-Message-State: AOJu0Yy+ebUUCN5qOwJ8PFHSuXNp0zGyLfIaC3tuFZ100bicBEwMOQAt iCRGnrpQgcTNzYZmw2slbIVjIOAyOqyXF/QX50CdLZyKfZ2piE4D+fsAorY97Q== X-Gm-Gg: ASbGncvK/PBze9Y0U1o7rapv7rFr+ZErF+khmz5EuMFrKZy+/R9Lonkj2vT71dAKbag PcaVA3J60dGbzrPazQHE6fcxkB7IpEI6sW1QOUP0NSlhiKgDDb9Vjap5nD5KXp0ip+NonsnJjJX wuKNnXxpmDV96ms9rO5fnbJQuksrrdONDK4Ax8PLgtYHolYs7dSzID4+yxoyY+9u9t6BPIkIc15 3QrDnz8IWuqNZVAR/sSee+atuC6tphl4CZPzwovmSoyKiknKsEkyx4OyocMNiXhrCgNKv/nV+FK TLb+Ax62aHSTUeoTI+sC+ZHOQHprfZYWtLSx9De2yM8HLcxCnMjG4WghUMpXppICrcBiMXlU6gJ ePo4aDjLhPTyVgeghozSWzz6PjlZAMI0FGaMYLINr4k2b2fgKH7uI6GPXC24M7vrlQARY/sF5hh 4NJ0APCXpBQvM5+wM= X-Google-Smtp-Source: AGHT+IHRnnUB9BZoTPQGE/aH5IPRU062dEZHTF0y6Fy2pggR9iHt/qtwWzkxg+Yr9YVd/3FxsMtvXw== X-Received: by 2002:a17:90b:4d8d:b0:340:f422:fc76 with SMTP id 98e67ed59e1d1-349a23f7b44mr158083a91.0.1764961344665; Fri, 05 Dec 2025 11:02:24 -0800 (PST) Received: from gmail.com ([2402:e280:3e9b:22f:e515:8350:8116:2469]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3494f2e43d9sm5169439a91.0.2025.12.05.11.02.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Dec 2025 11:02:24 -0800 (PST) From: Sumeet Pawnikar To: rafael@kernel.org, linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, sumeet4linux@gmail.com Subject: [PATCH] powercap: fix race condition in register_control_type Date: Sat, 6 Dec 2025 00:32:16 +0530 Message-ID: <20251205190216.5032-1-sumeet4linux@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 --- drivers/powercap/powercap_sys.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/powercap/powercap_sys.c b/drivers/powercap/powercap_sy= s.c index 4112a0097338..bdc65e040d17 100644 --- a/drivers/powercap/powercap_sys.c +++ b/drivers/powercap/powercap_sys.c @@ -625,17 +625,22 @@ struct powercap_control_type *powercap_register_contr= ol_type( INIT_LIST_HEAD(&control_type->node); control_type->dev.class =3D &powercap_class; dev_set_name(&control_type->dev, "%s", name); - result =3D device_register(&control_type->dev); - if (result) { - put_device(&control_type->dev); - return ERR_PTR(result); - } idr_init(&control_type->idr); =20 mutex_lock(&powercap_cntrl_list_lock); list_add_tail(&control_type->node, &powercap_cntrl_list); mutex_unlock(&powercap_cntrl_list_lock); =20 + result =3D 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); --=20 2.43.0