From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta-65-227.siemens.flowmailer.net (mta-65-227.siemens.flowmailer.net [185.136.65.227]) (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 335F31D4173 for ; Thu, 17 Oct 2024 11:51:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.136.65.227 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729165873; cv=none; b=l+mSSi6R409Sio2L88S1+Z+bEFyIZCE9yOPOvSbhAp2SIy+xdLlHPNJTVeQU+YeJI9baQ+g5pAVuKp/NePFDIIJu7tbI9c7CNQ2olnVu4I+C+nCbAMLXYSO7cN88N7Bc+kupSYIEtjo1Jsn/jpFIM8GJ4nfHDQkP0guxfhgCHdA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729165873; c=relaxed/simple; bh=BvlT8Bj1/037cUewa0hHnmYjbLsPmkVCgq+QJY1rApo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=EwJPyR22M94P4vyqC4CDb0yo7dz6r5GZ2Cj8ob/HotKX+nt8DxeaismgbbFSMajgIZBzUu83sNVG6qLdFD5MSMeVtsMt3BOHYBPqUhkO551RoOS1viTeA2xnBHg5fj88OYjYezQp4fd7hZBDuEBp7Hi3wLBX8dwY02IZl+g22Cw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com; dkim=pass (2048-bit key) header.d=siemens.com header.i=felix.moessbauer@siemens.com header.b=LJ0um/nV; arc=none smtp.client-ip=185.136.65.227 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=siemens.com header.i=felix.moessbauer@siemens.com header.b="LJ0um/nV" Received: by mta-65-227.siemens.flowmailer.net with ESMTPSA id 20241017115100f1b3860b606210027a for ; Thu, 17 Oct 2024 13:51:00 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm1; d=siemens.com; i=felix.moessbauer@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc:References:In-Reply-To; bh=xehMTjjkfTLF9mI9dDqz4sbMLUpydX86XmxXhzZ/5JE=; b=LJ0um/nVIFDxccPSxh9QB8166XGVgff29EnyLaOIarw3ANc1VQZ63WY3BC12AnEeQ9pJr0 TL9V5Dk6mXkLamyytfJI/88pLMtj5uNPFlEoJiJE5hAyrpTDF7FVslwz6uFR6UvVehCA26fT eDmZyOukPXe91cHZTIyK8LSCQzqyvlh+QGqb94vPxtmcK4kcTSJ/yNkcl2OW+ZLsdQy6AoKX Vj6+lya8AAPQBbPnko5je8flI5ahlXvJ8Wyi/1gWDxt4/KvLepaXv1Y+Rmhp3PlL09Zsp8dx bx8EszO/0wgvBJym3Dceg3P+FHCGPhuzhwet05WhIcloQSiexivUKsMw==; From: Felix Moessbauer To: stable@vger.kernel.org Cc: io-uring@vger.kernel.org, axboe@kernel.dk, gregkh@linuxfoundation.org, kernel test robot , Felix Moessbauer Subject: [PATCH 5.10 5.15 2/3] io_uring/sqpoll: retain test for whether the CPU is valid Date: Thu, 17 Oct 2024 13:50:28 +0200 Message-Id: <20241017115029.178246-2-felix.moessbauer@siemens.com> In-Reply-To: <20241017115029.178246-1-felix.moessbauer@siemens.com> References: <20241017115029.178246-1-felix.moessbauer@siemens.com> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-1321639:519-21489:flowmailer From: Jens Axboe commit a09c17240bdf2e9fa6d0591afa9448b59785f7d4 upstream. A recent commit ensured that SQPOLL cannot be setup with a CPU that isn't in the current tasks cpuset, but it also dropped testing whether the CPU is valid in the first place. Without that, if a task passes in a CPU value that is too high, the following KASAN splat can get triggered: BUG: KASAN: stack-out-of-bounds in io_sq_offload_create+0x858/0xaa4 Read of size 8 at addr ffff800089bc7b90 by task wq-aff.t/1391 CPU: 4 UID: 1000 PID: 1391 Comm: wq-aff.t Not tainted 6.11.0-rc7-00227-g371c468f4db6 #7080 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace.part.0+0xcc/0xe0 show_stack+0x14/0x1c dump_stack_lvl+0x58/0x74 print_report+0x16c/0x4c8 kasan_report+0x9c/0xe4 __asan_report_load8_noabort+0x1c/0x24 io_sq_offload_create+0x858/0xaa4 io_uring_setup+0x1394/0x17c4 __arm64_sys_io_uring_setup+0x6c/0x180 invoke_syscall+0x6c/0x260 el0_svc_common.constprop.0+0x158/0x224 do_el0_svc+0x3c/0x5c el0_svc+0x34/0x70 el0t_64_sync_handler+0x118/0x124 el0t_64_sync+0x168/0x16c The buggy address belongs to stack of task wq-aff.t/1391 and is located at offset 48 in frame: io_sq_offload_create+0x0/0xaa4 This frame has 1 object: [32, 40) 'allowed_mask' The buggy address belongs to the virtual mapping at [ffff800089bc0000, ffff800089bc9000) created by: kernel_clone+0x124/0x7e0 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000d740af80 pfn:0x11740a memcg:ffff0000c2706f02 flags: 0xbffe00000000000(node=0|zone=2|lastcpupid=0x1fff) raw: 0bffe00000000000 0000000000000000 dead000000000122 0000000000000000 raw: ffff0000d740af80 0000000000000000 00000001ffffffff ffff0000c2706f02 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff800089bc7a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff800089bc7b00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 >ffff800089bc7b80: 00 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff800089bc7c00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 ffff800089bc7c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f3 Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202409161632.cbeeca0d-lkp@intel.com Fixes: f011c9cf04c0 ("io_uring/sqpoll: do not allow pinning outside of cpuset") Tested-by: Felix Moessbauer Signed-off-by: Jens Axboe Signed-off-by: Felix Moessbauer --- io_uring/io_uring.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 6b6fd244233f8..a260852a0490c 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -8751,6 +8751,8 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, int cpu = p->sq_thread_cpu; ret = -EINVAL; + if (cpu >= nr_cpu_ids || !cpu_online(cpu)) + goto err_sqpoll; cpuset_cpus_allowed(current, &allowed_mask); if (!cpumask_test_cpu(cpu, &allowed_mask)) goto err_sqpoll; -- 2.39.5