KASAN: use-after-free Write in init_timer

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.14	KASAN: use-after-free Write in init_timer_key	C			1	415d	1350d	0/1	upstream: reported C repro on 2020/08/07 15:50
==================================================================
BUG: KASAN: use-after-free in do_init_timer kernel/time/timer.c:845 [inline]
BUG: KASAN: use-after-free in init_timer_key+0x32c/0x340 kernel/time/timer.c:870
Write of size 8 at addr ffff888023225500 by task kworker/u4:3/46

CPU: 0 PID: 46 Comm: kworker/u4:3 Not tainted 5.19.0-rc5-syzkaller-01108-gace2bee839e0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
Workqueue: bat_events batadv_dat_purge
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313
 print_report mm/kasan/report.c:429 [inline]
 kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491
 do_init_timer kernel/time/timer.c:845 [inline]
 init_timer_key+0x32c/0x340 kernel/time/timer.c:870
 batadv_dat_start_timer+0x113/0x190 net/batman-adv/distributed-arp-table.c:104
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>

Allocated by task 18156:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:436 [inline]
 ____kasan_kmalloc mm/kasan/common.c:515 [inline]
 ____kasan_kmalloc mm/kasan/common.c:474 [inline]
 __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524
 kmalloc_node include/linux/slab.h:623 [inline]
 kvmalloc_node+0xa4/0x190 mm/util.c:613
 kvmalloc include/linux/slab.h:750 [inline]
 kvzalloc include/linux/slab.h:758 [inline]
 alloc_netdev_mqs+0x98/0x1180 net/core/dev.c:10598
 rtnl_create_link+0x9d7/0xc00 net/core/rtnetlink.c:3241
 rtnl_newlink_create net/core/rtnetlink.c:3353 [inline]
 __rtnl_newlink+0xf8f/0x17e0 net/core/rtnetlink.c:3580
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593
 rtnetlink_rcv_msg+0x43a/0xc90 net/core/rtnetlink.c:6089
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:734
 __sys_sendto+0x21a/0x320 net/socket.c:2116
 __do_sys_sendto net/socket.c:2128 [inline]
 __se_sys_sendto net/socket.c:2124 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2124
 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+0x46/0xb0

Freed by task 91:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328
 kasan_slab_free include/linux/kasan.h:200 [inline]
 slab_free_hook mm/slub.c:1754 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780
 slab_free mm/slub.c:3536 [inline]
 kfree+0xd6/0x4d0 mm/slub.c:4584
 kvfree+0x42/0x50 mm/util.c:655
 device_release+0x9f/0x240 drivers/base/core.c:2230
 kobject_cleanup lib/kobject.c:673 [inline]
 kobject_release lib/kobject.c:704 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1c8/0x540 lib/kobject.c:721
 netdev_run_todo+0x75e/0x10f0 net/core/dev.c:10380
 default_device_exit_batch+0x44e/0x590 net/core/dev.c:11352
 ops_exit_list+0x125/0x170 net/core/net_namespace.c:167
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302

Last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348
 insert_work+0x48/0x350 kernel/workqueue.c:1358
 __queue_work+0x62f/0x1150 kernel/workqueue.c:1517
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1514 [inline]
 __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1790
 __run_timers kernel/time/timer.c:1768 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571

Second to last potentially related work creation:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348
 insert_work+0x48/0x350 kernel/workqueue.c:1358
 __queue_work+0x62f/0x1150 kernel/workqueue.c:1517
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1514 [inline]
 __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1790
 __run_timers kernel/time/timer.c:1768 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571

The buggy address belongs to the object at ffff888023224000
 which belongs to the cache kmalloc-cg-8k of size 8192
The buggy address is located 5376 bytes inside of
 8192-byte region [ffff888023224000, ffff888023226000)

The buggy address belongs to the physical page:
page:ffffea00008c8800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23220
head:ffffea00008c8800 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff88801184c3c0
raw: 0000000000000000 0000000000020002 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 0xd60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3620, tgid 3620 (syz-executor.3), ts 57315029143, free_ts 57295095862
 prep_new_page mm/page_alloc.c:2456 [inline]
 get_page_from_freelist+0x1290/0x3b70 mm/page_alloc.c:4198
 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5426
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272
 alloc_slab_page mm/slub.c:1824 [inline]
 allocate_slab+0x26c/0x3c0 mm/slub.c:1969
 new_slab mm/slub.c:2029 [inline]
 ___slab_alloc+0x9c4/0xe20 mm/slub.c:3031
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118
 slab_alloc_node mm/slub.c:3209 [inline]
 __kmalloc_node+0x2cb/0x390 mm/slub.c:4490
 kmalloc_node include/linux/slab.h:623 [inline]
 kvmalloc_node+0xa4/0x190 mm/util.c:613
 kvmalloc include/linux/slab.h:750 [inline]
 kvzalloc include/linux/slab.h:758 [inline]
 netif_alloc_netdev_queues net/core/dev.c:9928 [inline]
 alloc_netdev_mqs+0x9ba/0x1180 net/core/dev.c:10657
 rtnl_create_link+0x9d7/0xc00 net/core/rtnetlink.c:3241
 rtnl_newlink_create net/core/rtnetlink.c:3353 [inline]
 __rtnl_newlink+0xf8f/0x17e0 net/core/rtnetlink.c:3580
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593
 rtnetlink_rcv_msg+0x43a/0xc90 net/core/rtnetlink.c:6089
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1371 [inline]
 free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1421
 free_unref_page_prepare mm/page_alloc.c:3343 [inline]
 free_unref_page+0x19/0x6a0 mm/page_alloc.c:3438
 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2548
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446
 kasan_slab_alloc include/linux/kasan.h:224 [inline]
 slab_post_alloc_hook mm/slab.h:750 [inline]
 slab_alloc_node mm/slub.c:3243 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 kmem_cache_alloc_trace+0x26d/0x3f0 mm/slub.c:3282
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 ref_tracker_alloc+0x14c/0x550 lib/ref_tracker.c:85
 __netdev_tracker_alloc include/linux/netdevice.h:3960 [inline]
 netdev_hold include/linux/netdevice.h:3989 [inline]
 netdev_hold include/linux/netdevice.h:3984 [inline]
 netdev_queue_add_kobject net/core/net-sysfs.c:1663 [inline]
 netdev_queue_update_kobjects+0x1a7/0x4e0 net/core/net-sysfs.c:1718
 register_queue_kobjects net/core/net-sysfs.c:1779 [inline]
 netdev_register_kobject+0x330/0x400 net/core/net-sysfs.c:2019
 register_netdevice+0xd9d/0x15e0 net/core/dev.c:10065
 vxcan_newlink+0x272/0x610 drivers/net/can/vxcan.c:221
 rtnl_newlink_create net/core/rtnetlink.c:3363 [inline]
 __rtnl_newlink+0x1087/0x17e0 net/core/rtnetlink.c:3580
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593
 rtnetlink_rcv_msg+0x43a/0xc90 net/core/rtnetlink.c:6089
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501

Memory state around the buggy address:
 ffff888023225400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888023225480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888023225500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888023225580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888023225600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================