kasan reported a user-after-free. I'm using a kvm machine, it panic
during boot. I'm using the latest linux tree. which contains below.
commit d377535405686f735b90a8ad4ba269484cd7c96e
Author: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Date: Tue Jun 5 05:26:33 2018 -0400
dm: Use kzalloc for all structs with embedded biosets/mempools
[ 58.836774] ==================================================================
[ 58.839974] BUG: KASAN: use-after-free in __wake_up_common+0x7c7/0x880
[ 58.841988] Read of size 8 at addr ffff88025a47c3e8 by task kswapd0/66
[ 58.843986]
[ 58.845644]
[ 58.846127] Allocated by task 956:
[ 58.847249]
[ 58.847731] Freed by task 956:
[ 58.848856]
[ 58.849336] The buggy address belongs to the object at ffff88025a47c000
[ 58.849336] which belongs to the cache names_cache of size 4096
[ 58.853276] The buggy address is located 1000 bytes inside of
[ 58.853276] 4096-byte region [ffff88025a47c000, ffff88025a47d000)
[ 58.856924] The buggy address belongs to the page:
[ 58.858411] page:ffffea0009691f00 count:1 mapcount:0
mapping:0000000000000000 index:0x0 compound_mapcount: 0
[ 58.861443] flags: 0x6fffff80008100(slab|head)
[ 58.862820] raw: 006fffff80008100 0000000000000000 0000000000000000
0000000100010001
[ 58.865197] raw: dead000000000100 dead000000000200 ffff88012d940a00
0000000000000000
[ 58.867590] page dumped because: kasan: bad access detected
[ 58.869409]
[ 58.869933] Memory state around the buggy address:
[ 58.871116] ffff88025a47c280: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 58.872195] ffff88025a47c300: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 58.873295] >ffff88025a47c380: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 58.874358] ^
[ 58.875334] ffff88025a47c400: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 58.876395] ffff88025a47c480: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[ 58.877453] ==================================================================
[ 58.878547] BUG: unable to handle kernel NULL pointer dereference
at 0000000000000000
[ 58.879708] PGD 0 P4D 0
[ 58.880107] Oops: 0010 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN PTI
[ 58.881013] CPU: 0 PID: 66 Comm: kswapd0 Tainted: G B W
4.17.0.fi+ #41
[ 58.881944] Hardware name: Red Hat KVM, BIOS 0.0.0 02/06/2015
[ 58.882646] RIP: 0010: (null)
[ 58.883106] Code: Bad RIP value.
[ 58.883520] RSP: 0018:ffff88012ec07818 EFLAGS: 00010086
[ 58.884158] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 58.885020] RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff88025a47c3d0
[ 58.886576] RBP: ffff880257960418 R08: ffff88025a47c3d0 R09: fffffbfff09587a4
[ 58.888370] R10: fffffbfff09587a4 R11: ffffffff84ac3d23 R12: ffffffffffffffe8
[ 58.890257] R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88012ec07910
[ 58.892113] FS: 0000000000000000(0000) GS:ffff88012ec00000(0000)
knlGS:0000000000000000
[ 58.894194] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 58.895648] CR2: ffffffffffffffd6 CR3: 0000000004214000 CR4: 00000000001406f0
[ 58.897468] Call Trace:
[ 58.898117] <IRQ>
[ 58.898716] ? __wake_up_common+0x18e/0x880
[ 58.899843] ? wait_woken+0x340/0x340
[ 58.900842] ? do_raw_spin_lock+0xcf/0x220
[ 58.901665] ? __wake_up_common_lock+0xe3/0x170
[ 58.902439] ? __wake_up_common+0x880/0x880
[ 58.903077] ? time_hardirqs_off+0x3e/0x4f0
[ 58.903742] ? _raw_spin_unlock_irqrestore+0x45/0xa0
[ 58.904486] ? mempool_free+0x270/0x3a0
[ 58.905185] ? bio_free+0x104/0x190
[ 58.905722] ? bio_put+0xb9/0x120
[ 58.906235] ? dec_pending+0x3cd/0xbe0 [dm_mod]
[ 58.906960] ? time_hardirqs_off+0x30/0x4f0
[ 58.907602] ? debug_check_no_locks_freed+0x260/0x260
[ 58.908389] ? alloc_io+0x820/0x820 [dm_mod]
[ 58.909130] ? linear_status+0x1b0/0x1b0 [dm_mod]
[ 58.909839] ? clone_endio+0x1ed/0x890 [dm_mod]
[ 58.910691] ? bio_disassociate_task+0x16e/0x450
[ 58.911453] ? dm_get_queue_limits+0x110/0x110 [dm_mod]
[ 58.912288] ? check_preemption_disabled+0x36/0x2a0
[ 58.913075] ? dm_get_queue_limits+0x110/0x110 [dm_mod]
[ 58.913919] ? bio_endio+0x423/0x8b0
[ 58.914513] ? blk_update_request+0x295/0xe40
[ 58.915215] ? virtqueue_get_buf_ctx+0x3b0/0xa60 [virtio_ring]
[ 58.916171] ? blk_mq_end_request+0x56/0x390
[ 58.916877] ? blk_mq_complete_request+0x36a/0x6e0
[ 58.917857] ? virtblk_done+0x1bc/0x450 [virtio_blk]
[ 58.918690] ? 0xffffffffa0158000
[ 58.919260] ? __lock_is_held+0xb6/0x170
[ 58.919917] ? check_preemption_disabled+0x36/0x2a0
[ 58.920730] ? 0xffffffffa0158000
[ 58.921300] ? vring_interrupt+0x170/0x280 [virtio_ring]
[ 58.922176] ? vring_alloc_queue+0x400/0x400 [virtio_ring]
[ 58.923080] ? __handle_irq_event_percpu+0x117/0x9a0
[ 58.923908] ? handle_irq_event_percpu+0x77/0x180
[ 58.924691] ? __handle_irq_event_percpu+0x9a0/0x9a0
[ 58.925519] ? do_raw_spin_unlock+0x156/0x250
[ 58.926257] ? handle_irq_event+0xc6/0x1a0
[ 58.926943] ? handle_edge_irq+0x229/0xd40
[ 58.927747] ? handle_irq+0x2e2/0x5fd
[ 58.928528] ? check_preemption_disabled+0x36/0x2a0
[ 58.929545] ? do_IRQ+0xa7/0x240
[ 58.930241] ? common_interrupt+0xf/0xf
[ 58.931072] </IRQ>
[ 58.931576] ? lock_acquire+0x184/0x470
[ 58.932395] ? list_lru_count_one+0xb8/0x3a0
[ 58.933330] ? list_lru_count_one+0x86/0x3a0
[ 58.934362] ? super_cache_count+0x152/0x2f0
[ 58.935268] ? shrink_slab.part.24+0x1fe/0xc60
[ 58.936205] ? mem_cgroup_from_task+0x180/0x180
[ 58.937162] ? prepare_kswapd_sleep+0x160/0x160
[ 58.938101] ? mem_cgroup_iter+0x165/0xc60
[ 58.938955] ? shrink_slab+0x9e/0xd0
[ 58.939707] ? shrink_node+0x3f1/0x17b0
[ 58.940675] ? shrink_node_memcg+0x1f10/0x1f10
[ 58.941794] ? mem_cgroup_iter+0x165/0xc60
[ 58.942668] ? mem_cgroup_nr_lru_pages+0xe0/0xe0
[ 58.943642] ? inactive_list_is_low+0x1f3/0x6e0
[ 58.944598] ? balance_pgdat+0x2c9/0x950
[ 58.945436] ? mem_cgroup_shrink_node+0x7d0/0x7d0
[ 58.946432] ? preempt_count_sub+0x101/0x190
[ 58.947340] ? check_preemption_disabled+0x36/0x2a0
[ 58.948373] ? kswapd+0x5c1/0x1060
[ 58.949109] ? balance_pgdat+0x950/0x950
[ 58.949948] ? __kthread_parkme+0x84/0x240
[ 58.950816] ? __kthread_parkme+0xff/0x240
[ 58.951685] ? finish_wait+0x3f0/0x3f0
[ 58.952484] ? schedule+0x92/0x230
[ 58.953202] ? balance_pgdat+0x950/0x950
[ 58.954030] ? balance_pgdat+0x950/0x950
[ 58.954861] ? kthread+0x37d/0x500
[ 58.955592] ? kthread_create_worker_on_cpu+0xe0/0xe0
[ 58.956654] ? ret_from_fork+0x3a/0x50
[ 58.957457] Modules linked in: sunrpc snd_hda_codec_generic
crct10dif_pclmul snd_hda_intel crc32_pclmul ghash_clmulni_intel
snd_hda_codec snd_hda_core snd_hwdep vfat fat iTCO_wdt
iTCO_vendor_support snd_seq snd_seq_device snd_pcm pcspkr
virtio_balloon snd_timer i2c_i801 sg lpc_ich snd soundcore shpchp
ip_tables xfs libcrc32c sr_mod cdrom virtio_net net_failover
virtio_scsi failover virtio_blk virtio_console bochs_drm
drm_kms_helper syscopyarea sysfillrect 8139too sysimgblt fb_sys_fops
ttm drm crc32c_intel ahci libahci 8139cp libata serio_raw mii i2c_core
virtio_pci virtio_ring virtio dm_mirror dm_region_hash dm_log dm_mod
[ 58.968856] CR2: 0000000000000000
[ 58.969583] ---[ end trace 70ad259a1fd9713f ]---
[ 58.970624] RIP: 0010: (null)
[ 58.971417] Code: Bad RIP value.
[ 58.972095] RSP: 0018:ffff88012ec07818 EFLAGS: 00010086
[ 58.973181] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 58.974635] RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff88025a47c3d0
[ 58.976060] RBP: ffff880257960418 R08: ffff88025a47c3d0 R09: fffffbfff09587a4
[ 58.977495] R10: fffffbfff09587a4 R11: ffffffff84ac3d23 R12: ffffffffffffffe8
[ 58.978922] R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88012ec07910
[ 58.980365] FS: 0000000000000000(0000) GS:ffff88012ec00000(0000)
knlGS:0000000000000000
[ 58.981984] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 58.983139] CR2: ffffffffffffffd6 CR3: 0000000004214000 CR4: 00000000001406f0
[ 58.984568] Kernel panic - not syncing: Fatal exception in interrupt
[ 60.070024] Shutting down cpus with NMI
[ 60.070741] Kernel Offset: disabled
[ 60.071317] ---[ end Kernel panic - not syncing: Fatal exception in
interrupt ]---
On 6 June 2018 at 22:18, Jens Axboe <axboe@xxxxxxxxx> wrote:
> On 6/6/18 2:41 AM, Kent Overstreet wrote:
>> On Wed, Jun 06, 2018 at 04:37:25PM +0800, Li Wang wrote:
>>> Hi BIO experts,
>>>
>>> I catch this panic issue on some kind of arches(x86_64, ppc64,
>>> ppc64le..), it seems the root cause is very probably from BIO changes
>>> from kernel-4.17-rc7. Plz take a look.
>>
>> That's the bioset changes, the fix is out and on its way in
>
> It's already in mainline, since about lunch time yesterday.
>
>
> --
> Jens Axboe
>
