Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935197AbdCWOK5 (ORCPT ); Thu, 23 Mar 2017 10:10:57 -0400 Received: from mail-vk0-f54.google.com ([209.85.213.54]:34862 "EHLO mail-vk0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751576AbdCWOK4 (ORCPT ); Thu, 23 Mar 2017 10:10:56 -0400 MIME-Version: 1.0 From: Dmitry Vyukov Date: Thu, 23 Mar 2017 15:09:44 +0100 Message-ID: Subject: loop: WARNING in sysfs_remove_group To: Jens Axboe , Ming Lei , Hannes Reinecke , Mike Christie , Omar Sandoval , mnghuan@gmail.com, Petr Mladek , LKML Cc: syzkaller Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3597 Lines: 77 Hello, I've got the following WARNING while running syzkaller on 093b995e3b55a0ae0670226ddfcb05bfbf0099ae. Note the preceding injected kmalloc failure, most likely it's the root cause. FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 3 PID: 21172 Comm: syz-executor4 Not tainted 4.11.0-rc3+ #364 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x1b8/0x28d lib/dump_stack.c:52 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x78a/0x870 lib/fault-inject.c:154 should_failslab+0xec/0x120 mm/failslab.c:31 slab_pre_alloc_hook mm/slab.h:434 [inline] slab_alloc mm/slab.c:3394 [inline] kmem_cache_alloc+0x200/0x720 mm/slab.c:3570 kmem_cache_zalloc include/linux/slab.h:653 [inline] __kernfs_new_node+0xd1/0x430 fs/kernfs/dir.c:629 kernfs_new_node+0x80/0xf0 fs/kernfs/dir.c:661 kernfs_create_dir_ns+0x41/0x140 fs/kernfs/dir.c:933 kernfs_create_dir include/linux/kernfs.h:477 [inline] internal_create_group+0xf7/0x8f0 fs/sysfs/group.c:124 sysfs_create_group+0x1f/0x30 fs/sysfs/group.c:156 loop_sysfs_init drivers/block/loop.c:802 [inline] loop_set_fd drivers/block/loop.c:940 [inline] lo_ioctl+0xbbf/0x1670 drivers/block/loop.c:1341 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0xcf6/0x1f80 block/ioctl.c:594 block_ioctl+0xde/0x120 fs/block_dev.c:1978 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1af/0x16d0 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x445b79 RSP: 002b:00007f8df2ef7858 EFLAGS: 00000286 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000708000 RCX: 0000000000445b79 RDX: 0000000000000006 RSI: 0000000000004c00 RDI: 0000000000000005 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000286 R12: 00000000004a7e31 R13: 0000000000000000 R14: 00007f8df2ef7618 R15: 00007f8df2ef7788 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 21188 at fs/sysfs/group.c:237 sysfs_remove_group+0x167/0x1c0 fs/sysfs/group.c:235 sysfs group 'loop' not found for kobject 'loop6' Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 21188 Comm: syz-executor4 Not tainted 4.11.0-rc3+ #364 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x1b8/0x28d lib/dump_stack.c:52 panic+0x20c/0x423 kernel/panic.c:180 __warn+0x1c4/0x1e0 kernel/panic.c:541 warn_slowpath_fmt+0xc1/0x100 kernel/panic.c:564 sysfs_remove_group+0x167/0x1c0 fs/sysfs/group.c:235 loop_sysfs_exit drivers/block/loop.c:808 [inline] loop_clr_fd+0x46d/0xa90 drivers/block/loop.c:1055 lo_ioctl+0x1dc/0x1670 drivers/block/loop.c:1348 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0xcf6/0x1f80 block/ioctl.c:594 block_ioctl+0xde/0x120 fs/block_dev.c:1978 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1af/0x16d0 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x445b79 RSP: 002b:00007f8df2ed6858 EFLAGS: 00000286 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000007080a8 RCX: 0000000000445b79 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000005 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000286 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8df2ed79c0 R15: 00007f8df2ed7700