KASAN: use-after-free Read in __cpuhp_state_remove_instance

syzbot
2021-02-26T09:49:47Z

Hello,

syzbot found the following issue on:

HEAD commit: d01f2f7e Add linux-next specific files for 20210226
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1750e9b0d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=a1746d2802a82a05
dashboard link: https://syzkaller.appspot.com/bug?extid=38769495e847cea2dcca

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+38769495e847cea2dcca@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:835 [inline]
BUG: KASAN: use-after-free in hlist_del include/linux/list.h:852 [inline]
BUG: KASAN: use-after-free in __cpuhp_state_remove_instance+0x58b/0x5b0 kernel/cpu.c:2002
Read of size 8 at addr ffff88801582fb98 by task syz-executor.5/15523

CPU: 1 PID: 15523 Comm: syz-executor.5 Not tainted 5.11.0-next-20210226-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0xfa/0x151 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232
__kasan_report mm/kasan/report.c:399 [inline]
kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
__hlist_del include/linux/list.h:835 [inline]
hlist_del include/linux/list.h:852 [inline]
__cpuhp_state_remove_instance+0x58b/0x5b0 kernel/cpu.c:2002
cpuhp_state_remove_instance_nocalls include/linux/cpuhotplug.h:407 [inline]
io_wq_create+0x6ca/0xbf0 fs/io-wq.c:1056
io_init_wq_offload fs/io_uring.c:7792 [inline]
io_uring_alloc_task_context+0x1bf/0x6a0 fs/io_uring.c:7811
io_uring_add_task_file+0x261/0x350 fs/io_uring.c:8773
io_uring_install_fd fs/io_uring.c:9381 [inline]
io_uring_create fs/io_uring.c:9532 [inline]
io_uring_setup+0x14c7/0x2be0 fs/io_uring.c:9571
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x465ef9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7ba953b108 EFLAGS: 00000202 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 000000000056c0b0 RCX: 0000000000465ef9
RDX: 0000000020ffb000 RSI: 0000000020000080 RDI: 00000000000050bb
RBP: 0000000020000080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000020ffb000 R14: 0000000020000000 R15: 0000000020ee7000

Allocated by task 15523:
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:427 [inline]
____kasan_kmalloc mm/kasan/common.c:506 [inline]
____kasan_kmalloc mm/kasan/common.c:465 [inline]
__kasan_kmalloc+0x99/0xc0 mm/kasan/common.c:515
kmalloc include/linux/slab.h:554 [inline]
kzalloc include/linux/slab.h:684 [inline]
io_wq_create+0xc0/0xbf0 fs/io-wq.c:1002
io_init_wq_offload fs/io_uring.c:7792 [inline]
io_uring_alloc_task_context+0x1bf/0x6a0 fs/io_uring.c:7811
io_uring_add_task_file+0x261/0x350 fs/io_uring.c:8773
io_uring_install_fd fs/io_uring.c:9381 [inline]
io_uring_create fs/io_uring.c:9532 [inline]
io_uring_setup+0x14c7/0x2be0 fs/io_uring.c:9571
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 15523:
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:357
____kasan_slab_free mm/kasan/common.c:360 [inline]
____kasan_slab_free mm/kasan/common.c:325 [inline]
__kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367
kasan_slab_free include/linux/kasan.h:199 [inline]
slab_free_hook mm/slub.c:1562 [inline]
slab_free_freelist_hook+0x72/0x1b0 mm/slub.c:1600
slab_free mm/slub.c:3161 [inline]
kfree+0xe5/0x7b0 mm/slub.c:4213
io_wq_destroy fs/io-wq.c:1091 [inline]
io_wq_put+0x4d0/0x6d0 fs/io-wq.c:1098
io_wq_create+0x92d/0xbf0 fs/io-wq.c:1053
io_init_wq_offload fs/io_uring.c:7792 [inline]
io_uring_alloc_task_context+0x1bf/0x6a0 fs/io_uring.c:7811
io_uring_add_task_file+0x261/0x350 fs/io_uring.c:8773
io_uring_install_fd fs/io_uring.c:9381 [inline]
io_uring_create fs/io_uring.c:9532 [inline]
io_uring_setup+0x14c7/0x2be0 fs/io_uring.c:9571
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

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:345
insert_work+0x48/0x370 kernel/workqueue.c:1331
__queue_work+0x5c1/0xf00 kernel/workqueue.c:1497
queue_work_on+0xae/0xc0 kernel/workqueue.c:1524
queue_work include/linux/workqueue.h:507 [inline]
netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:658 [inline]
netdevice_event+0x3aa/0x720 drivers/infiniband/core/roce_gid_mgmt.c:801
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2063
call_netdevice_notifiers_extack net/core/dev.c:2075 [inline]
call_netdevice_notifiers net/core/dev.c:2089 [inline]
unregister_netdevice_many+0x942/0x1760 net/core/dev.c:10905
default_device_exit_batch+0x2fa/0x3c0 net/core/dev.c:11425
ops_exit_list+0x10d/0x160 net/core/net_namespace.c:178
cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:595
process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
kthread+0x3b1/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

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:345
insert_work+0x48/0x370 kernel/workqueue.c:1331
__queue_work+0x5c1/0xf00 kernel/workqueue.c:1497
queue_work_on+0xae/0xc0 kernel/workqueue.c:1524
queue_work include/linux/workqueue.h:507 [inline]
call_usermodehelper_exec+0x1f0/0x4c0 kernel/umh.c:433
kobject_uevent_env+0xf9f/0x1680 lib/kobject_uevent.c:617
rx_queue_add_kobject net/core/net-sysfs.c:1020 [inline]
net_rx_queue_update_kobjects+0xee/0x450 net/core/net-sysfs.c:1060
register_queue_kobjects net/core/net-sysfs.c:1742 [inline]
netdev_register_kobject+0x275/0x430 net/core/net-sysfs.c:1990
register_netdevice+0xd33/0x14a0 net/core/dev.c:10178
__ip_tunnel_create+0x398/0x5c0 net/ipv4/ip_tunnel.c:267
ip_tunnel_init_net+0x330/0x9c0 net/ipv4/ip_tunnel.c:1061
vti_init_net+0x2a/0x360 net/ipv4/ip_vti.c:501
ops_init+0xaf/0x470 net/core/net_namespace.c:140
setup_net+0x40f/0xa30 net/core/net_namespace.c:333
copy_net_ns+0x31e/0x760 net/core/net_namespace.c:474
create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
copy_namespaces+0x385/0x440 kernel/nsproxy.c:178
copy_process+0x2ab5/0x6fd0 kernel/fork.c:2100
kernel_clone+0xe7/0xab0 kernel/fork.c:2462
__do_sys_clone+0xc8/0x110 kernel/fork.c:2579
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88801582fb00
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 152 bytes inside of
192-byte region [ffff88801582fb00, ffff88801582fbc0)
The buggy address belongs to the page:
page:000000007dcd9156 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1582f
flags: 0xfff00000000200(slab)
raw: 00fff00000000200 ffffea000071b7c0 0000000400000004 ffff888010841a00
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88801582fa80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff88801582fb00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801582fb80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff88801582fc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801582fc80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.