From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6F5EDEE57DF for ; Mon, 11 Sep 2023 13:53:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=zzqvzQsL65C8BV+sk1rIb3Wxk8novKuo2KOPxq6Rrsg=; b=xglbOC0zlcuYiv IQbs9ErvXy/QNMqHLICwfgKMjOOYVaK/8WJPpV5DcLKpdrj/2KMy6qHkfgjH0UU3GgT+AdeDGkZMf 1gKIvGpHUk5aGKdVGG6m+gqqx1798691YNH8CxG3xxqfxvWWncVR3PEbAAPV64tjPxkYnyv9NcNqg ZI//IqRbG8pgE1O13pry0oThdXrFF2IsoXV2I56psKYIensMeQuhRkcyJOBe4UrPNy81gQ4Z8uk/c sDT+Iwco2gFJR+rbvPDU5MlNV2KxSo24jyQWSikEN32y27GIsmFsvw3pvniJzDT+5qhawwJ7WJQEd N0KFHvVDdjkpgSQYDTyw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qfhLz-000e9N-2X; Mon, 11 Sep 2023 13:53:27 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qfhLw-000e8R-10 for linux-arm-kernel@lists.infradead.org; Mon, 11 Sep 2023 13:53:26 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2487D61180; Mon, 11 Sep 2023 13:53:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36A84C433C8; Mon, 11 Sep 2023 13:53:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694440402; bh=JjCF7Wx0lVt8SeQDM2dFHSKWW7LA9C5vXS8TrSro9wY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dgApSD54KPFw/fokDBJhgoAmQKUA3aZMDegDwLBMpzLZll0+mIK3cEG+FfpiwDeWN hs3BjwZOZkPLhCi3UYPEcwRyzPh1jBoHsfSUPq/zBGwb6GuzaHdCA1wRDWInbtv7p9 UJeTXcFnxjopgg2jf8uThtc6nd4yBKXnUzZnwlgU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Russell King , Arnd Bergmann , Lecopzer Chen , Oleg Nesterov , linux-arm-kernel@lists.infradead.org, Arnd Bergmann , Kees Cook , Sasha Levin Subject: [PATCH 6.5 022/739] ARM: ptrace: Restore syscall skipping for tracers Date: Mon, 11 Sep 2023 15:37:01 +0200 Message-ID: <20230911134651.665981774@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134650.921299741@linuxfoundation.org> References: <20230911134650.921299741@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230911_065324_555774_2F4D0AC7 X-CRM114-Status: GOOD ( 16.33 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook [ Upstream commit 4697b5848bd933f68ebd04836362c8de0cacaf71 ] Since commit 4e57a4ddf6b0 ("ARM: 9107/1: syscall: always store thread_info->abi_syscall"), the seccomp selftests "syscall_errno" and "syscall_faked" have been broken. Both seccomp and PTRACE depend on using the special value of "-1" for skipping syscalls. This value wasn't working because it was getting masked by __NR_SYSCALL_MASK in both PTRACE_SET_SYSCALL and get_syscall_nr(). Explicitly test for -1 in PTRACE_SET_SYSCALL and get_syscall_nr(), leaving it exposed when present, allowing tracers to skip syscalls again. Cc: Russell King Cc: Arnd Bergmann Cc: Lecopzer Chen Cc: Oleg Nesterov Cc: linux-arm-kernel@lists.infradead.org Fixes: 4e57a4ddf6b0 ("ARM: 9107/1: syscall: always store thread_info->abi_syscall") Reviewed-by: Arnd Bergmann Link: https://lore.kernel.org/r/20230810195422.2304827-2-keescook@chromium.org Signed-off-by: Kees Cook Signed-off-by: Sasha Levin --- arch/arm/include/asm/syscall.h | 3 +++ arch/arm/kernel/ptrace.c | 5 +++-- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/syscall.h b/arch/arm/include/asm/syscall.h index dfeed440254a8..fe4326d938c18 100644 --- a/arch/arm/include/asm/syscall.h +++ b/arch/arm/include/asm/syscall.h @@ -25,6 +25,9 @@ static inline int syscall_get_nr(struct task_struct *task, if (IS_ENABLED(CONFIG_AEABI) && !IS_ENABLED(CONFIG_OABI_COMPAT)) return task_thread_info(task)->abi_syscall; + if (task_thread_info(task)->abi_syscall == -1) + return -1; + return task_thread_info(task)->abi_syscall & __NR_SYSCALL_MASK; } diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index 2d8e2516906b6..fef32d73f9120 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -783,8 +783,9 @@ long arch_ptrace(struct task_struct *child, long request, break; case PTRACE_SET_SYSCALL: - task_thread_info(child)->abi_syscall = data & - __NR_SYSCALL_MASK; + if (data != -1) + data &= __NR_SYSCALL_MASK; + task_thread_info(child)->abi_syscall = data; ret = 0; break; -- 2.40.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel