From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) (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 10C665813E for ; Wed, 13 Mar 2024 21:44:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710366276; cv=none; b=jUZkqe6BPpR7OHeawckzqYWHw5g1oRE0xn4FHObktNXMise3+AbGurySPDN8UEOEsSZC12SyV+ndcmFv5k1oqIH97G1ECA671LDMZASf/I9hVpShJzuX5vpx+GDZ1nLnp7B0c2JgWVIniVL5Gzg7qCGMtq7XldcupI1kN6dwMtA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710366276; c=relaxed/simple; bh=M7tMssL3rW6daJmlY8YzvszCMnWhcIOBZ0pI+5TVFAg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BARzTDnYNecf+nh5KPpW7M7gcdcVdow6WM9i4cQv03LnensNIS8iCT4lxlbk+7NreKsR1qjW/jXCBuzCwYLgxByyGS5kYCvXzDqffQN22V76czjmCfrMZRtpwR89Jm7PaG4xVjAPV2YI7aLpFFfK0tYSHsPdo9sO5pQusXUtKyQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Dr7Mz7hh; arc=none smtp.client-ip=209.85.214.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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="Dr7Mz7hh" Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-1dddaa02d22so2060835ad.2 for ; Wed, 13 Mar 2024 14:44:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1710366274; x=1710971074; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=TqpXVYBsDQDgSl0PQ61LrhAcbX98gzLbSWwdys5RLvI=; b=Dr7Mz7hhdOcnWrjy2IStgZTaq3Mq0JKlIyS9xzBr7dVBtsP1N+ERWw0aUz+m+Ma0C7 RFGpZQutkCeDosFbjrUOtxhRGoHnDcCcC5POO8a0WhIZAa48MLIT/Fq7UQbKogxIjZbv QzSQatKv8W6QkVKF48mlkdeIaQ1h4XmbZm6G0aSPxv5kcc8+3eke7uOld8aFoVmYPWrs w6VknKtjdv0XOBgCZwOK0bOZgQMPXR9gkhHUy9al2s5Dx0Og9GUCCcn4yUnEzgrOxtMx PnOm/W5KJvllCTzeYp8DuhTr8DPWZ7gLY7L75yucgE1GCyF6kis3icQCLgmSq3PWiEo9 2uUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710366274; x=1710971074; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=TqpXVYBsDQDgSl0PQ61LrhAcbX98gzLbSWwdys5RLvI=; b=lCJa+oUp7nwiAPK8w2p2M5sfgv0AKsrKtmqn6rAk8auJJPwv38CLsC5ZMBkQakH9xm MuVh3Lc64JBvTpAG/Jrome8PsPgCgi7CzddWmIbdficE+9eq1UJVAoMz0leic8Kr80BI gsf6Gsa0wqxsOjWN66rnTyy+OTUDXLrkpCeTPBmU8i+/XCPiEspTcC2KQWHTJra1tmE8 QSpyEkWduZraGz7BjP5RUsftG0nn++hGzvo8SUSm0Rgie38tukBd6wwhES27w/jbjsfB GRhzFCtHOnJyfAdvx8OdX/VSj/3lvr+XgxzHlYvWfvVKc3h+UyvoAlp7fmrWejUQjik2 XPug== X-Forwarded-Encrypted: i=1; AJvYcCX3AW9LS8N43tx6LXVQddUxq7oVfk+OvKi6FqQFOiyKg4LMJgfFs1TZlF35SvGKQO0ulHzc/jH6mV1OM3NpgrJ7MzPFoe7nKwX24U/8 X-Gm-Message-State: AOJu0YwWjRtqHdz70IG2Lpr1oOrdfkrgyTQKoAIkH/CY1nLP10zIV3IV mBr9G8ZSYEzWbebCLkCSbHI6TzqC0GYgOsqn7UmRI4xz5BG8HTHoLuMo5mVW X-Google-Smtp-Source: AGHT+IGTROaHYXxzf+17P2vGGsVAJyT79RM3PPgmRinvxxlvM/ysxERHCOBQZqY+QnILlv5GLoVePw== X-Received: by 2002:a17:902:7890:b0:1dc:51ac:88f5 with SMTP id q16-20020a170902789000b001dc51ac88f5mr33054pll.65.1710366274322; Wed, 13 Mar 2024 14:44:34 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::5:2875]) by smtp.gmail.com with ESMTPSA id b5-20020a170902650500b001dd7d66ac95sm91424plk.78.2024.03.13.14.44.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Mar 2024 14:44:33 -0700 (PDT) Sender: Tejun Heo Date: Wed, 13 Mar 2024 11:44:32 -1000 From: Tejun Heo To: Alan Stern Cc: Bart Van Assche , Greg KH , Kernel development list Subject: Re: [PATCH] fs: sysfs: Fix reference leak in sysfs_break_active_protection() Message-ID: References: <2024030428-graph-harmful-1597@gregkh> <416a8311-c725-419a-8b22-74c80207347f@rowland.harvard.edu> <9c2484f4-df62-4d23-97a2-55a160eba55f@rowland.harvard.edu> <8a4d3f0f-c5e3-4b70-a188-0ca433f9e6f9@rowland.harvard.edu> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8a4d3f0f-c5e3-4b70-a188-0ca433f9e6f9@rowland.harvard.edu> On Wed, Mar 13, 2024 at 05:43:41PM -0400, Alan Stern wrote: > The sysfs_break_active_protection() routine has an obvious reference > leak in its error path. If the call to kernfs_find_and_get() fails then > kn will be NULL, so the companion sysfs_unbreak_active_protection() > routine won't get called (and would only cause an access violation by > trying to dereference kn->parent if it was called). As a result, the > reference to kobj acquired at the start of the function will never be > released. > > Fix the leak by adding an explicit kobject_put() call when kn is NULL. > > Signed-off-by: Alan Stern > Fixes: 2afc9166f79b ("scsi: sysfs: Introduce sysfs_{un,}break_active_protection()") > Cc: Bart Van Assche > Cc: Acked-by: Tejun Heo Thanks. -- tejun