From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3775223-1519416010-2-18397345181953813694 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519416009; b=MDupuu/pEcQmIEtdXAnvjPF+sk8bX2splXsJBs2iMvtWPpx Mtljw7/46IENdtjDyBK6hCYLOB6aK93o4eOPzMctxzmqr2+6KaJxPJV1wLwij8xL BmoC1o2xWrBiDKM9SehLQxbmuO+EaexH232ElunOnd59prCX319Bp8UXg8ZQ/jBj EVVukyXn2FmzZWUwAwONjO3KzWIN6+u+3wFDrzvL2SXKtaPvmb+MjiL0lnYDYuV5 0nk+BrM/RpBfLj4d+NmMBpCuWmsmlvkKKaTufHJ64lr0+cBbA7AxRbFmqQNlCbCq ySdy+PX5pviovk5v05t3smAnmnOjPAIR8R/7nLA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1519416009; bh=4nuGZZ3Rw9BAqghrK3cDjXZvyU u1kPumnq3JXjqhf2I=; b=Uggwz8AMm6+SdUpHVet0JYN6QytaZXezyS0zWREeai vnjZjxpHiBC4km+GmgAVDYnimoPWTMb6fFlMD1E/qPZhfomnJdmraqL6+kiqRSj3 0bc2LusCYKcsKr2RZnrSLXBr4hoR5Ocyx4bteg0PggnK6pbTOStw7K5P5Lv384sr S2H7EA9lAg0R2Q8jRJM+VADsizYSvCs9MBQGFmanY5IBx24YiXhh7x06PHO8U8EI 47MveUqSv2/x3YMNiRDWdqeThpSSqekYH0r8RNaEIi9jx0yp8AOh5Y9W73O6o/4A 0zyKkspwQINE5amLs8YjWVuHRauGZtikY+PGFipOoijA== ARC-Authentication-Results: i=1; mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Authentication-Results: mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754793AbeBWT7z (ORCPT ); Fri, 23 Feb 2018 14:59:55 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:42336 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933386AbeBWSnq (ORCPT ); Fri, 23 Feb 2018 13:43:46 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ben Hutchings Subject: [PATCH 4.9 037/145] staging: android: ashmem: Fix a race condition in pin ioctls Date: Fri, 23 Feb 2018 19:25:43 +0100 Message-Id: <20180223170729.749650378@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180223170724.669759283@linuxfoundation.org> References: <20180223170724.669759283@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings commit ce8a3a9e76d0193e2e8d74a06d275b3c324ca652 upstream. ashmem_pin_unpin() reads asma->file and asma->size before taking the ashmem_mutex, so it can race with other operations that modify them. Build-tested only. Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/staging/android/ashmem.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) --- a/drivers/staging/android/ashmem.c +++ b/drivers/staging/android/ashmem.c @@ -719,30 +719,32 @@ static int ashmem_pin_unpin(struct ashme size_t pgstart, pgend; int ret = -EINVAL; + mutex_lock(&ashmem_mutex); + if (unlikely(!asma->file)) - return -EINVAL; + goto out_unlock; - if (unlikely(copy_from_user(&pin, p, sizeof(pin)))) - return -EFAULT; + if (unlikely(copy_from_user(&pin, p, sizeof(pin)))) { + ret = -EFAULT; + goto out_unlock; + } /* per custom, you can pass zero for len to mean "everything onward" */ if (!pin.len) pin.len = PAGE_ALIGN(asma->size) - pin.offset; if (unlikely((pin.offset | pin.len) & ~PAGE_MASK)) - return -EINVAL; + goto out_unlock; if (unlikely(((__u32)-1) - pin.offset < pin.len)) - return -EINVAL; + goto out_unlock; if (unlikely(PAGE_ALIGN(asma->size) < pin.offset + pin.len)) - return -EINVAL; + goto out_unlock; pgstart = pin.offset / PAGE_SIZE; pgend = pgstart + (pin.len / PAGE_SIZE) - 1; - mutex_lock(&ashmem_mutex); - switch (cmd) { case ASHMEM_PIN: ret = ashmem_pin(asma, pgstart, pgend); @@ -755,6 +757,7 @@ static int ashmem_pin_unpin(struct ashme break; } +out_unlock: mutex_unlock(&ashmem_mutex); return ret;