From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751282AbeFDUVE (ORCPT ); Mon, 4 Jun 2018 16:21:04 -0400 Received: from mail-io0-f200.google.com ([209.85.223.200]:53026 "EHLO mail-io0-f200.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751058AbeFDUVC (ORCPT ); Mon, 4 Jun 2018 16:21:02 -0400 X-Google-Smtp-Source: ADUXVKKVSYtTMFwKPAWofVd65PihksQks388VSPisb/+g0An2j+Q7JjLWjJgUWMaLx8yQLqzuBiECK7PurGAFWa2Sjc3l5FOZVVz MIME-Version: 1.0 Date: Mon, 04 Jun 2018 13:21:02 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000271c83056dd6acc6@google.com> Subject: bpf-next boot error: KASAN: use-after-free Write in call_usermodehelper_exec_work From: syzbot To: linux-kernel@vger.kernel.org, mcgrof@kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 69b450789136 Merge branch 'misc-BPF-improvements' git tree: bpf-next console output: https://syzkaller.appspot.com/x/log.txt?x=1080d1d7800000 kernel config: https://syzkaller.appspot.com/x/.config?x=e4078980b886800c dashboard link: https://syzkaller.appspot.com/bug?extid=2c73319c406f1987d156 compiler: gcc (GCC) 8.0.1 20180413 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+2c73319c406f1987d156@syzkaller.appspotmail.com kworker/u4:1 (36) used greatest stack depth: 23056 bytes left cpuidle: using governor menu ACPI: bus type PCI registered PCI: Using configuration type 1 for base access ================================================================== BUG: KASAN: use-after-free in call_usermodehelper_exec_work+0x2d3/0x310 kernel/umh.c:195 Write of size 4 at addr ffff8801d9202370 by task kworker/u4:2/50 CPU: 0 PID: 50 Comm: kworker/u4:2 Not tainted 4.17.0-rc6+ #32 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound call_usermodehelper_exec_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_store4_noabort+0x17/0x20 mm/kasan/report.c:437 call_usermodehelper_exec_work+0x2d3/0x310 kernel/umh.c:195 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Allocated by task 1: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 kmalloc include/linux/slab.h:512 [inline] kzalloc include/linux/slab.h:701 [inline] call_usermodehelper_setup+0xe8/0x400 kernel/umh.c:382 kobject_uevent_env+0xb21/0x1110 lib/kobject_uevent.c:608 kobject_uevent+0x1f/0x30 lib/kobject_uevent.c:636 kernel_add_sysfs_param kernel/params.c:798 [inline] param_sysfs_builtin kernel/params.c:833 [inline] param_sysfs_init+0x3f9/0x486 kernel/params.c:954 do_one_initcall+0x127/0x913 init/main.c:884 do_initcall_level init/main.c:952 [inline] do_initcalls init/main.c:960 [inline] do_basic_setup init/main.c:978 [inline] kernel_init_freeable+0x49b/0x58e init/main.c:1135 kernel_init+0x11/0x1b3 init/main.c:1061 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Freed by task 208: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 call_usermodehelper_freeinfo kernel/umh.c:45 [inline] umh_complete+0x7b/0x90 kernel/umh.c:59 call_usermodehelper_exec_async+0x6e8/0x9e0 kernel/umh.c:116 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 The buggy address belongs to the object at ffff8801d9202300 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 112 bytes inside of 192-byte region [ffff8801d9202300, ffff8801d92023c0) The buggy address belongs to the page: page:ffffea0007648080 count:1 mapcount:0 mapping:ffff8801d9202000 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801d9202000 0000000000000000 0000000100000010 raw: ffffea0007647f60 ffff8801da801148 ffff8801da800040 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d9202200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d9202280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801d9202300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d9202380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801d9202400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This bug is generated by a bot. 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