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[23.128.96.18]) by mx.google.com with ESMTP id gn24si5667827ejc.244.2021.04.23.06.53.09; Fri, 23 Apr 2021 06:53:39 -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 S229931AbhDWNwt (ORCPT + 99 others); Fri, 23 Apr 2021 09:52:49 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:28601 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229794AbhDWNwt (ORCPT ); Fri, 23 Apr 2021 09:52:49 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4FRbLx0RLgz9ttC6; Fri, 23 Apr 2021 15:52:09 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id nksP2VPKskja; Fri, 23 Apr 2021 15:52:09 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4FRbLw6llJz9ttC5; Fri, 23 Apr 2021 15:52:08 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id E9C678B865; Fri, 23 Apr 2021 15:52:10 +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 iidl2mxlih71; Fri, 23 Apr 2021 15:52:10 +0200 (CEST) Received: from po15610vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id B435C8B765; Fri, 23 Apr 2021 15:52:10 +0200 (CEST) Received: by po15610vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 763D96397D; Fri, 23 Apr 2021 13:52:10 +0000 (UTC) Message-Id: From: Christophe Leroy Subject: [PATCH] powerpc/signal32: Fix erroneous SIGSEGV on RT signal return To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Fri, 23 Apr 2021 13:52:10 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return of user_read_access_begin() is tested the wrong way, leading to a SIGSEGV when the user address is valid and likely an Oops when the user address is bad. Fix the test. Fixes: 887f3ceb51cd ("powerpc/signal32: Convert do_setcontext[_tm]() to user access block") Signed-off-by: Christophe Leroy --- arch/powerpc/kernel/signal_32.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index fc41c58f0cbb..8f05ed0da292 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -967,7 +967,7 @@ static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sigset_t set; struct mcontext __user *mcp; - if (user_read_access_begin(ucp, sizeof(*ucp))) + if (!user_read_access_begin(ucp, sizeof(*ucp))) return -EFAULT; unsafe_get_sigset_t(&set, &ucp->uc_sigmask, failed); @@ -1005,7 +1005,7 @@ static int do_setcontext_tm(struct ucontext __user *ucp, u32 cmcp; u32 tm_cmcp; - if (user_read_access_begin(ucp, sizeof(*ucp))) + if (!user_read_access_begin(ucp, sizeof(*ucp))) return -EFAULT; unsafe_get_sigset_t(&set, &ucp->uc_sigmask, failed); -- 2.25.0