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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE928C54EBD for ; Thu, 12 Jan 2023 15:34:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230460AbjALPei (ORCPT ); Thu, 12 Jan 2023 10:34:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240399AbjALPeF (ORCPT ); Thu, 12 Jan 2023 10:34:05 -0500 Received: from mail-il1-f200.google.com (mail-il1-f200.google.com [209.85.166.200]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65BDB6144B for ; Thu, 12 Jan 2023 07:24:57 -0800 (PST) Received: by mail-il1-f200.google.com with SMTP id a7-20020a056e0208a700b0030ecfd5d4cdso1606942ilt.9 for ; Thu, 12 Jan 2023 07:24:57 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Tx8vies8TxyvxQ+rYNyjuUQwsIU5p8yX5/b5vwL2Gb4=; b=OJNx7BXGDsh+uim1qzW0NwgOjxDuaaas+6otJYlRG9I+b9pt6T3Ex3gUgd14CIx4eX ylm2LlEnc+K+ZvesAS7t9h1f4Hc8kAA4HvoRRL9vIj7dnSZOoViIVry7SVaKj7VBeLSJ 5YRPfqrG0ycJk6Qg024E4AOBUw+aCjN/ubDS4BKTYzlx8Xz8XgT5E5hcFbJxrID2X0N1 BSuiMt1hQeTDeQ8x1WmQOuJ6le8nW8tx52tDU9Yf/ONS7K93cVBg8cBVR9ubnN3J1yJW 7E1mtQniY19Xr7t03MARvYYMsY6ks4OvBHCgi6moSjDNlx0GHauoLXZ5LqdF75lHQ2fk ig/A== X-Gm-Message-State: AFqh2kpp9FxJVvEG6X0ntHKOGmG3IwRQtj1YYJgUZgTUmrmphM5l02It DwEeQUCBi3Y8iG5hhMQwzpg3dGpmAeq1ZahJkVzhlp+Yr4i8 X-Google-Smtp-Source: AMrXdXutKmf7G9Ql1E6hjDLR1jg7PvhGYaeUzTiuecAoj7mQEfpvwfTEzz+RSa25MG9DTlZS/zXjug+w2JtfQY5moL6xLUnyd7+p MIME-Version: 1.0 X-Received: by 2002:a05:6638:2a8:b0:38a:3f3c:8b0d with SMTP id d8-20020a05663802a800b0038a3f3c8b0dmr6941617jaq.181.1673537083025; Thu, 12 Jan 2023 07:24:43 -0800 (PST) Date: Thu, 12 Jan 2023 07:24:43 -0800 In-Reply-To: <00000000000062f20e05f20e5b9e@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000005a33e305f212b7f3@google.com> Subject: Re: [syzbot] KASAN: use-after-free Read in io_fallback_tw From: syzbot To: asml.silence@gmail.com, axboe@kernel.dk, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org syzbot has found a reproducer for the following issue on: HEAD commit: 0a093b2893c7 Add linux-next specific files for 20230112 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=14b3995a480000 kernel config: https://syzkaller.appspot.com/x/.config?x=835f3591019836d5 dashboard link: https://syzkaller.appspot.com/bug?extid=ebcc33c1e81093c9224f compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11613181480000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=101a000e480000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/8111a570d6cb/disk-0a093b28.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ecc135b7fc9a/vmlinux-0a093b28.xz kernel image: https://storage.googleapis.com/syzbot-assets/ca8d73b446ea/bzImage-0a093b28.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ebcc33c1e81093c9224f@syzkaller.appspotmail.com ================================================================== BUG: KASAN: use-after-free in io_fallback_tw+0x6d/0x119 io_uring/io_uring.c:1249 Read of size 8 at addr ffff88802b270448 by task syz-executor235/5078 CPU: 0 PID: 5078 Comm: syz-executor235 Not tainted 6.2.0-rc3-next-20230112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:306 [inline] print_report+0x15e/0x45d mm/kasan/report.c:417 kasan_report+0xc0/0xf0 mm/kasan/report.c:517 io_fallback_tw+0x6d/0x119 io_uring/io_uring.c:1249 tctx_task_work.cold+0xf/0x2c io_uring/io_uring.c:1219 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xb17/0x2a90 kernel/exit.c:867 do_group_exit+0xd4/0x2a0 kernel/exit.c:1012 __do_sys_exit_group kernel/exit.c:1023 [inline] __se_sys_exit_group kernel/exit.c:1021 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1021 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f38f86551c9 Code: Unable to access opcode bytes at 0x7f38f865519f. RSP: 002b:00007ffce433d688 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f38f86c9350 RCX: 00007f38f86551c9 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f38f86c9350 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 Allocated by task 5078: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:325 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:769 [inline] kmem_cache_alloc_bulk+0x3aa/0x730 mm/slub.c:4033 __io_alloc_req_refill+0xcc/0x40b io_uring/io_uring.c:1062 io_alloc_req_refill io_uring/io_uring.h:348 [inline] io_submit_sqes.cold+0x7c/0xc2 io_uring/io_uring.c:2407 __do_sys_io_uring_enter+0x9e4/0x2c10 io_uring/io_uring.c:3429 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 33: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] kmem_cache_free+0xec/0x4e0 mm/slub.c:3809 io_req_caches_free+0x1a9/0x1e6 io_uring/io_uring.c:2737 io_ring_exit_work+0x2e7/0xc80 io_uring/io_uring.c:2967 process_one_work+0x9bf/0x1750 kernel/workqueue.c:2293 worker_thread+0x669/0x1090 kernel/workqueue.c:2440 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 The buggy address belongs to the object at ffff88802b2703c0 which belongs to the cache io_kiocb of size 216 The buggy address is located 136 bytes inside of 216-byte region [ffff88802b2703c0, ffff88802b270498) The buggy address belongs to the physical page: page:ffffea0000ac9c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b270 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffff88801c4e3280 dead000000000122 0000000000000000 raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5078, tgid 5078 (syz-executor235), ts 57698640196, free_ts 57658994184 prep_new_page mm/page_alloc.c:2549 [inline] get_page_from_freelist+0x11bb/0x2d50 mm/page_alloc.c:4324 __alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5590 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2281 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x350 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3193 __kmem_cache_alloc_bulk mm/slub.c:3951 [inline] kmem_cache_alloc_bulk+0x23d/0x730 mm/slub.c:4026 __io_alloc_req_refill+0xcc/0x40b io_uring/io_uring.c:1062 io_alloc_req_refill io_uring/io_uring.h:348 [inline] io_submit_sqes.cold+0x7c/0xc2 io_uring/io_uring.c:2407 __do_sys_io_uring_enter+0x9e4/0x2c10 io_uring/io_uring.c:3429 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1451 [inline] free_pcp_prepare+0x4d0/0x910 mm/page_alloc.c:1501 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page_list+0x176/0xcd0 mm/page_alloc.c:3528 release_pages+0xcb1/0x1330 mm/swap.c:1072 tlb_batch_pages_flush+0xa8/0x1a0 mm/mmu_gather.c:97 tlb_flush_mmu_free mm/mmu_gather.c:292 [inline] tlb_flush_mmu mm/mmu_gather.c:299 [inline] tlb_finish_mmu+0x14b/0x7e0 mm/mmu_gather.c:391 exit_mmap+0x202/0x7c0 mm/mmap.c:3100 __mmput+0x128/0x4c0 kernel/fork.c:1212 mmput+0x60/0x70 kernel/fork.c:1234 exec_mmap fs/exec.c:1034 [inline] begin_new_exec+0x1027/0x2f80 fs/exec.c:1293 load_elf_binary+0x801/0x4ff0 fs/binfmt_elf.c:1001 search_binary_handler fs/exec.c:1736 [inline] exec_binprm fs/exec.c:1778 [inline] bprm_execve fs/exec.c:1853 [inline] bprm_execve+0x7fd/0x1ae0 fs/exec.c:1809 do_execveat_common+0x72c/0x880 fs/exec.c:1960 do_execve fs/exec.c:2034 [inline] __do_sys_execve fs/exec.c:2110 [inline] __se_sys_execve fs/exec.c:2105 [inline] __x64_sys_execve+0x93/0xc0 fs/exec.c:2105 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88802b270300: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff88802b270380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff88802b270400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802b270480: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802b270500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================