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 X-Spam-Level: X-Spam-Status: No, score=-8.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D78AC432BE for ; Thu, 19 Aug 2021 10:44:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56C1D610A7 for ; Thu, 19 Aug 2021 10:44:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238320AbhHSKop (ORCPT ); Thu, 19 Aug 2021 06:44:45 -0400 Received: from mail-io1-f72.google.com ([209.85.166.72]:37576 "EHLO mail-io1-f72.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237005AbhHSKoo (ORCPT ); Thu, 19 Aug 2021 06:44:44 -0400 Received: by mail-io1-f72.google.com with SMTP id h3-20020a056602008300b005b7c0e23e11so3062100iob.4 for ; Thu, 19 Aug 2021 03:44:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:in-reply-to:message-id:subject :from:to; bh=NnrHY+0Ifj4stMjiYzo4dTxHnwfcr4wtUED0ExIjtpA=; b=Q4RBL1Kd3Ro6R+2pY39nxy0iRwTOLxjYbzySRgv2swS+GQ1aQ9XMQGbqrimLilK8uT i2IT4RAITCYljxdx/b2nn7GQKDoyLnbiqNE7hSL1J72Hru6g3nxHZKbxoS6QlHxji64W CGfd1TtZs0Eya5sWYJBOofrjAFo/gTnFFTztSeBkRR1b9x/PX/5OFICqtlU2OxNQ01lD HWiaq7uhaZYlnyGAIah8/YfTAFL80nlwotkBN5CrsqtB9SsR43o5LNuMW19gSUarUrp9 OmvetFr9t3AZdXf2lZM9uU85kYVv6Far9jiDYj/Dt/8zjf4CM0JuAWK3IHJG+zM4Mi9V BwXQ== X-Gm-Message-State: AOAM533IEYBOWvT28H8dVZDugEGq57g41RhnWbGbcjhZ1iX6hM1bt1kU RAjHhuS+PbLWlhIgi+waslZBjqDgz8n/Hs036uZBkqda9rcx X-Google-Smtp-Source: ABdhPJx1TcJSHMqV3xiO6gtNPn06oGIheguGbnqad41n5x9vN/jnwIoI4j+p1WILlnSlox3vNBMljICM6EM6FiF+8rvZS3p7123i MIME-Version: 1.0 X-Received: by 2002:a92:ce03:: with SMTP id b3mr9326399ilo.267.1629369847773; Thu, 19 Aug 2021 03:44:07 -0700 (PDT) Date: Thu, 19 Aug 2021 03:44:07 -0700 In-Reply-To: <858d47f0-48d5-fff5-24bb-346ebde4e127@gmail.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000fc001d05c9e73a85@google.com> Subject: Re: [syzbot] KASAN: use-after-free Read in tctx_task_work (2) 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: linux-kernel@vger.kernel.org Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: KASAN: use-after-free Read in tctx_task_work ================================================================== BUG: KASAN: use-after-free in ctx_flush_and_put fs/io_uring.c:2002 [inline] BUG: KASAN: use-after-free in tctx_task_work+0x307/0x310 fs/io_uring.c:2049 Read of size 4 at addr ffff888029d66358 by task syz-executor530/27775 CPU: 0 PID: 27775 Comm: syz-executor530 Not tainted 5.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:436 ctx_flush_and_put fs/io_uring.c:2002 [inline] tctx_task_work+0x307/0x310 fs/io_uring.c:2049 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xbae/0x2a30 kernel/exit.c:825 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2808 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x446729 Code: Unable to access opcode bytes at RIP 0x4466ff. RSP: 002b:00007fada1a521e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: 00000000000001d2 RBX: 00000000004cb458 RCX: 0000000000446729 RDX: 0000000000000000 RSI: 0000000000006b46 RDI: 0000000000000006 RBP: 00000000004cb450 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb45c R13: 00007ffff39bb49f R14: 00007fada1a52300 R15: 0000000000022000 Allocated by task 27776: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0x9b/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] io_ring_ctx_alloc fs/io_uring.c:1206 [inline] io_uring_create fs/io_uring.c:9685 [inline] io_uring_setup+0x27d/0x2cf0 fs/io_uring.c:9791 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 10491: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1625 [inline] slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1650 slab_free mm/slub.c:3210 [inline] kfree+0xe4/0x530 mm/slub.c:4264 io_ring_ctx_free fs/io_uring.c:8712 [inline] io_ring_exit_work+0x13ba/0x1930 fs/io_uring.c:8861 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:348 insert_work+0x48/0x370 kernel/workqueue.c:1332 __queue_work+0x5c1/0xed0 kernel/workqueue.c:1498 queue_work_on+0xee/0x110 kernel/workqueue.c:1525 queue_work include/linux/workqueue.h:507 [inline] io_ring_ctx_wait_and_kill+0x30a/0x3c0 fs/io_uring.c:8914 io_uring_release+0x3e/0x50 fs/io_uring.c:8922 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xbae/0x2a30 kernel/exit.c:825 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2808 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae Second to last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:348 insert_work+0x48/0x370 kernel/workqueue.c:1332 __queue_work+0x5c1/0xed0 kernel/workqueue.c:1498 queue_work_on+0xee/0x110 kernel/workqueue.c:1525 queue_work include/linux/workqueue.h:507 [inline] io_ring_ctx_wait_and_kill+0x30a/0x3c0 fs/io_uring.c:8914 io_uring_release+0x3e/0x50 fs/io_uring.c:8922 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xbae/0x2a30 kernel/exit.c:825 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2808 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888029d66000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 856 bytes inside of 4096-byte region [ffff888029d66000, ffff888029d67000) The buggy address belongs to the page: page:ffffea0000a75800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29d60 head:ffffea0000a75800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010842140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6467, ts 58396905717, free_ts 57689976074 prep_new_page mm/page_alloc.c:2436 [inline] get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4169 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5391 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244 alloc_slab_page mm/slub.c:1688 [inline] allocate_slab+0x32e/0x4b0 mm/slub.c:1828 new_slab mm/slub.c:1891 [inline] new_slab_objects mm/slub.c:2637 [inline] ___slab_alloc+0x4ba/0x820 mm/slub.c:2800 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2840 slab_alloc_node mm/slub.c:2922 [inline] slab_alloc mm/slub.c:2964 [inline] __kmalloc+0x312/0x330 mm/slub.c:4108 kmalloc include/linux/slab.h:596 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1332 vfs_getattr fs/stat.c:139 [inline] vfs_statx+0x164/0x390 fs/stat.c:207 vfs_fstatat fs/stat.c:225 [inline] vfs_lstat include/linux/fs.h:3386 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:380 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1346 [inline] free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1397 free_unref_page_prepare mm/page_alloc.c:3332 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3411 qlink_free mm/kasan/quarantine.c:146 [inline] qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 __kasan_slab_alloc+0x8e/0xa0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:2956 [inline] slab_alloc mm/slub.c:2964 [inline] kmem_cache_alloc+0x285/0x4a0 mm/slub.c:2969 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags include/linux/audit.h:319 [inline] getname+0x8e/0xd0 fs/namei.c:209 do_sys_openat2+0xf5/0x420 fs/open.c:1198 do_sys_open fs/open.c:1220 [inline] __do_sys_open fs/open.c:1228 [inline] __se_sys_open fs/open.c:1224 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1224 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888029d66200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888029d66280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888029d66300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888029d66380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888029d66400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Tested on: commit: bdd748b6 io-wq: move nr_running and worker_refs out of.. git tree: git://git.kernel.dk/linux-block for-5.15/io_uring console output: https://syzkaller.appspot.com/x/log.txt?x=13141b61300000 kernel config: https://syzkaller.appspot.com/x/.config?x=cb4282936412304f dashboard link: https://syzkaller.appspot.com/bug?extid=9c3492b27d10dc49ffa6 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1