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[23.128.96.18]) by mx.google.com with ESMTP id l5si15492166iln.118.2021.08.23.08.36.40; Mon, 23 Aug 2021 08:36:52 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231203AbhHWPgh (ORCPT + 99 others); Mon, 23 Aug 2021 11:36:37 -0400 Received: from pegase2.c-s.fr ([93.17.235.10]:52827 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229550AbhHWPgg (ORCPT ); Mon, 23 Aug 2021 11:36:36 -0400 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4GtbtH75CNz9sVN; Mon, 23 Aug 2021 17:35:51 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id izYZZl_Eawbw; Mon, 23 Aug 2021 17:35:51 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4GtbtH6DhNz9sT5; Mon, 23 Aug 2021 17:35:51 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id B21DC8B7AF; Mon, 23 Aug 2021 17:35:51 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id nmZS4ven9wac; Mon, 23 Aug 2021 17:35:51 +0200 (CEST) Received: from po18078vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.100]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 58C6B8B7AD; Mon, 23 Aug 2021 17:35:51 +0200 (CEST) Received: by po18078vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 4E4176BC7C; Mon, 23 Aug 2021 15:35:51 +0000 (UTC) Message-Id: From: Christophe Leroy Subject: [PATCH v2 1/5] powerpc/signal64: Access function descriptor with user access block To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Mon, 23 Aug 2021 15:35:51 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Access the function descriptor of the handler within a user access block. Signed-off-by: Christophe Leroy --- arch/powerpc/kernel/signal_64.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 1831bba0582e..790c450c2de8 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -936,8 +936,18 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, func_descr_t __user *funct_desc_ptr = (func_descr_t __user *) ksig->ka.sa.sa_handler; - err |= get_user(regs->ctr, &funct_desc_ptr->entry); - err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); + if (user_read_access_begin(funct_desc_ptr, sizeof(func_descr_t))) { + unsafe_get_user(regs->ctr, &funct_desc_ptr->entry, bad_funct_desc_block); + unsafe_get_user(regs->gpr[2], &funct_desc_ptr->toc, bad_funct_desc_block); + } else { + goto bad_funct_desc; +bad_funct_desc_block: + user_read_access_end(); +bad_funct_desc: + signal_fault(current, regs, __func__, funct_desc_ptr); + return 1; + } + user_read_access_end(); } /* enter the signal handler in native-endian mode */ -- 2.25.0