Received: by 2002:a05:6a10:206:0:0:0:0 with SMTP id 6csp2204732pxj; Thu, 20 May 2021 02:30:43 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxo5M+s3umbIMdtXP9RbNGDYbCqzXQnhI5MDbNsoOQfVVfHsvIYYfELGQLZVl1NNwUDYhV0 X-Received: by 2002:a17:906:a403:: with SMTP id l3mr3832988ejz.251.1621503043092; Thu, 20 May 2021 02:30:43 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1621503043; cv=none; d=google.com; s=arc-20160816; b=S16SQsiwCJHo/BiVCq0N+lC0185Kjt8goQDQpvU2U2PgEwvtPPKFyZzMbdPluclPg2 o8nhWMMthv4zfMyoXqd9nUNQyvPZXZ+arm+/Yye8Yg9oYs093qb9XJCvP3bUYsJyfCE+ OA6Ts8frFzIY1sT7G+MKLtGQE+9BeR6TrZ/3Xj3gFMfUHiRMXVxx725mnKva18tZoj39 8gP5tdEqHg6bY7gsSMTlo4ahpGDai/fmkEG0a8Avexfx1lLpXgLJVdtrXYlabW50tawJ E6ONjfdZARz5TK81IovDWU7fPjXxB4RqCODbTeb52PZjwuS8L3Kfi7RpYKMbV8Fw4lic B1ww== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=tkKWaNiK+p84zjZ3REmVNuaWEpHFmfU/1TPy+ZGy8HA=; b=yCu4Vo4qefHFleLJrHOstkPSf/3g0nV5nF06Fn6SEZFDTnYysdBfleDDuW2i6O5t3S rdjwUmsXkD4yOZgqtEhhe2PkSxyyxERkZI5hkRcMy6iq5vjrl9MQ2Mp2WjdCW5m3FI8V 35hfC/m6RxtzLaKZCNpjTH/loY1MT+uG+TCGV7FUtyCJPFy/XOEFa4GvXd5wS9edF8+g G6fFdnSi4ZlVaYB4wtvOMTuAvAzM4cH2kAH0H/KNh/cU26mvX9EeT+DmichZDOJSmKgk Uo6A7g58sRfAggU8JU6LIzumzeCVM4n5P0uG7G/7odUzv718Pj+m/A6+qi+KaLQOB0KE o8aA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=Ur4r4xVc; 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; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id g1si1803723edu.36.2021.05.20.02.30.18; Thu, 20 May 2021 02:30:43 -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; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=Ur4r4xVc; 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; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232199AbhETJ21 (ORCPT + 99 others); Thu, 20 May 2021 05:28:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:53500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231934AbhETJ1Z (ORCPT ); Thu, 20 May 2021 05:27:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D57BB6135C; Thu, 20 May 2021 09:26:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621502764; bh=7JjN/D17G6ME5Mc+DmYKPPS1cVShSzMCm9Pl9HYk81k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ur4r4xVcILns6NovbGQ22VAofcmyJtxgFEVW5IEMumrmlYUMtkzMAmoRTuuBTanPJ 7Qig48TKnBvsA2eZnK6c/vnv9yTdZda0AAdMAiOxt8AL+wQdieXiVSWRtYqYaVxeyh 8F5VrdHgzY65U9I6d6ZZkTY/MurYRJFj3x5UsaUY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, yangerkun , Pavel Begunkov , Jens Axboe , Sasha Levin Subject: [PATCH 5.12 39/45] block: reexpand iov_iter after read/write Date: Thu, 20 May 2021 11:22:27 +0200 Message-Id: <20210520092054.789347422@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092053.516042993@linuxfoundation.org> References: <20210520092053.516042993@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: yangerkun [ Upstream commit cf7b39a0cbf6bf57aa07a008d46cf695add05b4c ] We get a bug: BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x11c/0x404 lib/iov_iter.c:1139 Read of size 8 at addr ffff0000d3fb11f8 by task CPU: 0 PID: 12582 Comm: syz-executor.2 Not tainted 5.10.0-00843-g352c8610ccd2 #2 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x2d0 arch/arm64/kernel/stacktrace.c:132 show_stack+0x28/0x34 arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x110/0x164 lib/dump_stack.c:118 print_address_description+0x78/0x5c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report+0x148/0x1e4 mm/kasan/report.c:562 check_memory_region_inline mm/kasan/generic.c:183 [inline] __asan_load8+0xb4/0xbc mm/kasan/generic.c:252 iov_iter_revert+0x11c/0x404 lib/iov_iter.c:1139 io_read fs/io_uring.c:3421 [inline] io_issue_sqe+0x2344/0x2d64 fs/io_uring.c:5943 __io_queue_sqe+0x19c/0x520 fs/io_uring.c:6260 io_queue_sqe+0x2a4/0x590 fs/io_uring.c:6326 io_submit_sqe fs/io_uring.c:6395 [inline] io_submit_sqes+0x4c0/0xa04 fs/io_uring.c:6624 __do_sys_io_uring_enter fs/io_uring.c:9013 [inline] __se_sys_io_uring_enter fs/io_uring.c:8960 [inline] __arm64_sys_io_uring_enter+0x190/0x708 fs/io_uring.c:8960 __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline] invoke_syscall arch/arm64/kernel/syscall.c:48 [inline] el0_svc_common arch/arm64/kernel/syscall.c:158 [inline] do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:227 el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367 el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383 el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670 Allocated by task 12570: stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0xdc/0x120 mm/kasan/common.c:461 kasan_kmalloc+0xc/0x14 mm/kasan/common.c:475 __kmalloc+0x23c/0x334 mm/slub.c:3970 kmalloc include/linux/slab.h:557 [inline] __io_alloc_async_data+0x68/0x9c fs/io_uring.c:3210 io_setup_async_rw fs/io_uring.c:3229 [inline] io_read fs/io_uring.c:3436 [inline] io_issue_sqe+0x2954/0x2d64 fs/io_uring.c:5943 __io_queue_sqe+0x19c/0x520 fs/io_uring.c:6260 io_queue_sqe+0x2a4/0x590 fs/io_uring.c:6326 io_submit_sqe fs/io_uring.c:6395 [inline] io_submit_sqes+0x4c0/0xa04 fs/io_uring.c:6624 __do_sys_io_uring_enter fs/io_uring.c:9013 [inline] __se_sys_io_uring_enter fs/io_uring.c:8960 [inline] __arm64_sys_io_uring_enter+0x190/0x708 fs/io_uring.c:8960 __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline] invoke_syscall arch/arm64/kernel/syscall.c:48 [inline] el0_svc_common arch/arm64/kernel/syscall.c:158 [inline] do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:227 el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367 el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383 el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670 Freed by task 12570: stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track+0x38/0x6c mm/kasan/common.c:56 kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:355 __kasan_slab_free+0x124/0x150 mm/kasan/common.c:422 kasan_slab_free+0x10/0x1c mm/kasan/common.c:431 slab_free_hook mm/slub.c:1544 [inline] slab_free_freelist_hook mm/slub.c:1577 [inline] slab_free mm/slub.c:3142 [inline] kfree+0x104/0x38c mm/slub.c:4124 io_dismantle_req fs/io_uring.c:1855 [inline] __io_free_req+0x70/0x254 fs/io_uring.c:1867 io_put_req_find_next fs/io_uring.c:2173 [inline] __io_queue_sqe+0x1fc/0x520 fs/io_uring.c:6279 __io_req_task_submit+0x154/0x21c fs/io_uring.c:2051 io_req_task_submit+0x2c/0x44 fs/io_uring.c:2063 task_work_run+0xdc/0x128 kernel/task_work.c:151 get_signal+0x6f8/0x980 kernel/signal.c:2562 do_signal+0x108/0x3a4 arch/arm64/kernel/signal.c:658 do_notify_resume+0xbc/0x25c arch/arm64/kernel/signal.c:722 work_pending+0xc/0x180 blkdev_read_iter can truncate iov_iter's count since the count + pos may exceed the size of the blkdev. This will confuse io_read that we have consume the iovec. And once we do the iov_iter_revert in io_read, we will trigger the slab-out-of-bounds. Fix it by reexpand the count with size has been truncated. blkdev_write_iter can trigger the problem too. Signed-off-by: yangerkun Acked-by: Pavel Begunkov Link: https://lore.kernel.org/r/20210401071807.3328235-1-yangerkun@huawei.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- fs/block_dev.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 09d6f7229db9..a5a6a7930e5e 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1684,6 +1684,7 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) struct inode *bd_inode = bdev_file_inode(file); loff_t size = i_size_read(bd_inode); struct blk_plug plug; + size_t shorted = 0; ssize_t ret; if (bdev_read_only(I_BDEV(bd_inode))) @@ -1701,12 +1702,17 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) return -EOPNOTSUPP; - iov_iter_truncate(from, size - iocb->ki_pos); + size -= iocb->ki_pos; + if (iov_iter_count(from) > size) { + shorted = iov_iter_count(from) - size; + iov_iter_truncate(from, size); + } blk_start_plug(&plug); ret = __generic_file_write_iter(iocb, from); if (ret > 0) ret = generic_write_sync(iocb, ret); + iov_iter_reexpand(from, iov_iter_count(from) + shorted); blk_finish_plug(&plug); return ret; } @@ -1718,13 +1724,21 @@ ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) struct inode *bd_inode = bdev_file_inode(file); loff_t size = i_size_read(bd_inode); loff_t pos = iocb->ki_pos; + size_t shorted = 0; + ssize_t ret; if (pos >= size) return 0; size -= pos; - iov_iter_truncate(to, size); - return generic_file_read_iter(iocb, to); + if (iov_iter_count(to) > size) { + shorted = iov_iter_count(to) - size; + iov_iter_truncate(to, size); + } + + ret = generic_file_read_iter(iocb, to); + iov_iter_reexpand(to, iov_iter_count(to) + shorted); + return ret; } EXPORT_SYMBOL_GPL(blkdev_read_iter); -- 2.30.2