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 E3A142F7461; Tue, 12 Aug 2025 17:39:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755020398; cv=none; b=YFvtyiwiHZcr/Nyv1I/JpJaEzwH0xAyMfF10YmP9vUmWpJDV5pzAKOosl06qhlFB5ayEyWa0yRfghQWD4DyqVJjYVOhCuuyJ6wlVrMlJ99CvyFoP72GwDg751lfNWSnkcqqzV/9AccncQlvloAVzcGwhylSyu7peqiebH/VGft8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755020398; c=relaxed/simple; bh=HYvF/wxSevFp9pq6Marbz8O5g96v+wrRJx9sHyjBLrY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=smQj4MnrqKylAUN+9b9Jh8T0jq3ZxLHMUsXWZk+5lAnqiNVyg37PAeAb3rS98dphtCtHh5PjXJ0IBICFoNmRtMzodKFAJaQPNOr5tG+yvLz358qmwmBdYRUdjJhGZkbU31Qdn3nQf6mrMdXd1b924Y2elyf4RZrLXZ/6Nl7sn0s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zztGmu62; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zztGmu62" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 253FBC4CEF0; Tue, 12 Aug 2025 17:39:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755020397; bh=HYvF/wxSevFp9pq6Marbz8O5g96v+wrRJx9sHyjBLrY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zztGmu62Dv8bgWRQHK07UiQqKbZUP4St/UsSwkIOAyRHciZFa5Ip3cz/JeRljbnuN 7dSmb1wA3whNSn/dk9YV6SkBVGpwT3XwIOmvMJOg62MFdxWSibKzKnJ8dw5LoyNl8M /Lv2O1Eztikcu4srbP7mgA4edB6W3GAwhdVnnMHQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dmitry Vyukov , Thomas Gleixner , Sasha Levin Subject: [PATCH 6.1 070/253] selftests: Fix errno checking in syscall_user_dispatch test Date: Tue, 12 Aug 2025 19:27:38 +0200 Message-ID: <20250812172951.710715953@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250812172948.675299901@linuxfoundation.org> References: <20250812172948.675299901@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Vyukov [ Upstream commit b89732c8c8357487185f260a723a060b3476144e ] Successful syscalls don't change errno, so checking errno is wrong to ensure that a syscall has failed. For example for the following sequence: prctl(PR_SET_SYSCALL_USER_DISPATCH, op, 0x0, 0xff, 0); EXPECT_EQ(EINVAL, errno); prctl(PR_SET_SYSCALL_USER_DISPATCH, op, 0x0, 0x0, &sel); EXPECT_EQ(EINVAL, errno); only the first syscall may fail and set errno, but the second may succeed and keep errno intact, and the check will falsely pass. Or if errno happened to be EINVAL before, even the first check may falsely pass. Also use EXPECT/ASSERT consistently. Currently there is an inconsistent mix without obvious reasons for usage of one or another. Fixes: 179ef035992e ("selftests: Add kselftest for syscall user dispatch") Signed-off-by: Dmitry Vyukov Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/af6a04dbfef9af8570f5bab43e3ef1416b62699a.1747839857.git.dvyukov@google.com Signed-off-by: Sasha Levin --- .../syscall_user_dispatch/sud_test.c | 50 +++++++++---------- 1 file changed, 25 insertions(+), 25 deletions(-) diff --git a/tools/testing/selftests/syscall_user_dispatch/sud_test.c b/tools/testing/selftests/syscall_user_dispatch/sud_test.c index d975a6767329..48cf01aeec3e 100644 --- a/tools/testing/selftests/syscall_user_dispatch/sud_test.c +++ b/tools/testing/selftests/syscall_user_dispatch/sud_test.c @@ -79,6 +79,21 @@ TEST_SIGNAL(dispatch_trigger_sigsys, SIGSYS) } } +static void prctl_valid(struct __test_metadata *_metadata, + unsigned long op, unsigned long off, + unsigned long size, void *sel) +{ + EXPECT_EQ(0, prctl(PR_SET_SYSCALL_USER_DISPATCH, op, off, size, sel)); +} + +static void prctl_invalid(struct __test_metadata *_metadata, + unsigned long op, unsigned long off, + unsigned long size, void *sel, int err) +{ + EXPECT_EQ(-1, prctl(PR_SET_SYSCALL_USER_DISPATCH, op, off, size, sel)); + EXPECT_EQ(err, errno); +} + TEST(bad_prctl_param) { char sel = SYSCALL_DISPATCH_FILTER_ALLOW; @@ -86,57 +101,42 @@ TEST(bad_prctl_param) /* Invalid op */ op = -1; - prctl(PR_SET_SYSCALL_USER_DISPATCH, op, 0, 0, &sel); - ASSERT_EQ(EINVAL, errno); + prctl_invalid(_metadata, op, 0, 0, &sel, EINVAL); /* PR_SYS_DISPATCH_OFF */ op = PR_SYS_DISPATCH_OFF; /* offset != 0 */ - prctl(PR_SET_SYSCALL_USER_DISPATCH, op, 0x1, 0x0, 0); - EXPECT_EQ(EINVAL, errno); + prctl_invalid(_metadata, op, 0x1, 0x0, 0, EINVAL); /* len != 0 */ - prctl(PR_SET_SYSCALL_USER_DISPATCH, op, 0x0, 0xff, 0); - EXPECT_EQ(EINVAL, errno); + prctl_invalid(_metadata, op, 0x0, 0xff, 0, EINVAL); /* sel != NULL */ - prctl(PR_SET_SYSCALL_USER_DISPATCH, op, 0x0, 0x0, &sel); - EXPECT_EQ(EINVAL, errno); + prctl_invalid(_metadata, op, 0x0, 0x0, &sel, EINVAL); /* Valid parameter */ - errno = 0; - prctl(PR_SET_SYSCALL_USER_DISPATCH, op, 0x0, 0x0, 0x0); - EXPECT_EQ(0, errno); + prctl_valid(_metadata, op, 0x0, 0x0, 0x0); /* PR_SYS_DISPATCH_ON */ op = PR_SYS_DISPATCH_ON; /* Dispatcher region is bad (offset > 0 && len == 0) */ - prctl(PR_SET_SYSCALL_USER_DISPATCH, op, 0x1, 0x0, &sel); - EXPECT_EQ(EINVAL, errno); - prctl(PR_SET_SYSCALL_USER_DISPATCH, op, -1L, 0x0, &sel); - EXPECT_EQ(EINVAL, errno); + prctl_invalid(_metadata, op, 0x1, 0x0, &sel, EINVAL); + prctl_invalid(_metadata, op, -1L, 0x0, &sel, EINVAL); /* Invalid selector */ - prctl(PR_SET_SYSCALL_USER_DISPATCH, op, 0x0, 0x1, (void *) -1); - ASSERT_EQ(EFAULT, errno); + prctl_invalid(_metadata, op, 0x0, 0x1, (void *) -1, EFAULT); /* * Dispatcher range overflows unsigned long */ - prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_ON, 1, -1L, &sel); - ASSERT_EQ(EINVAL, errno) { - TH_LOG("Should reject bad syscall range"); - } + prctl_invalid(_metadata, PR_SYS_DISPATCH_ON, 1, -1L, &sel, EINVAL); /* * Allowed range overflows usigned long */ - prctl(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_ON, -1L, 0x1, &sel); - ASSERT_EQ(EINVAL, errno) { - TH_LOG("Should reject bad syscall range"); - } + prctl_invalid(_metadata, PR_SYS_DISPATCH_ON, -1L, 0x1, &sel, EINVAL); } /* -- 2.39.5