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 A06518F74 for ; Sun, 16 Jul 2023 20:15:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 216C5C433C7; Sun, 16 Jul 2023 20:15:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689538512; bh=jXJXyTPnfzD3E87H7ZSgoAAWIucKoAZyuDP9xss2pFs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ODSxHaKBXREODBW7gLCoXpFwzNDxUTWsrpsiAj7bO2o2sKztyX6Phn7/Zxwf3b2zp z43Zh4ZnU815n5LLXXMB/3y/QBvsN/tluZIZmChOTbfLn8XkG+ZO6saZF8i70Q59qs tJjzshVUMkwVDddtODgTBOUiNMkRM5zBO3aZ9aJo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sachin Sant , Nicholas Piggin , Michael Ellerman , Sasha Levin Subject: [PATCH 6.4 477/800] powerpc/64s: Fix VAS mm use after free Date: Sun, 16 Jul 2023 21:45:30 +0200 Message-ID: <20230716195000.158769348@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230716194949.099592437@linuxfoundation.org> References: <20230716194949.099592437@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Nicholas Piggin [ Upstream commit b4bda59b47879cce38a6ec5a01cd3cac702b5331 ] The refcount on mm is dropped before the coprocessor is detached. Reported-by: Sachin Sant Fixes: 7bc6f71bdff5f ("powerpc/vas: Define and use common vas_window struct") Fixes: b22f2d88e435c ("powerpc/pseries/vas: Integrate API with open/close windows") Signed-off-by: Nicholas Piggin Tested-by: Sachin Sant Signed-off-by: Michael Ellerman Link: https://msgid.link/20230607101024.14559-1-npiggin@gmail.com Signed-off-by: Sasha Levin --- arch/powerpc/platforms/powernv/vas-window.c | 2 +- arch/powerpc/platforms/pseries/vas.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c index 0072682531d80..b664838008c12 100644 --- a/arch/powerpc/platforms/powernv/vas-window.c +++ b/arch/powerpc/platforms/powernv/vas-window.c @@ -1310,8 +1310,8 @@ int vas_win_close(struct vas_window *vwin) /* if send window, drop reference to matching receive window */ if (window->tx_win) { if (window->user_win) { - put_vas_user_win_ref(&vwin->task_ref); mm_context_remove_vas_window(vwin->task_ref.mm); + put_vas_user_win_ref(&vwin->task_ref); } put_rx_win(window->rxwin); } diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c index 513180467562b..9a44a98ba3420 100644 --- a/arch/powerpc/platforms/pseries/vas.c +++ b/arch/powerpc/platforms/pseries/vas.c @@ -507,8 +507,8 @@ static int vas_deallocate_window(struct vas_window *vwin) vascaps[win->win_type].nr_open_windows--; mutex_unlock(&vas_pseries_mutex); - put_vas_user_win_ref(&vwin->task_ref); mm_context_remove_vas_window(vwin->task_ref.mm); + put_vas_user_win_ref(&vwin->task_ref); kfree(win); return 0; -- 2.39.2