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BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x20/0xb4 net/ethtool/ioctl.c:441
Read at addr fcf000000ab472e8 by task kworker/0:1/11
Pointer tag: [fc], memory tag: [fe]

CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT 
Hardware name: linux,dummy-virt (DT)
Workqueue: events smc_ib_port_event_work
Call trace:
 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x78/0x90 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x108/0x61c mm/kasan/report.c:482
 kasan_report+0x88/0xac mm/kasan/report.c:595
 report_tag_fault arch/arm64/mm/fault.c:326 [inline]
 do_tag_recovery arch/arm64/mm/fault.c:338 [inline]
 __do_kernel_fault+0x170/0x1c8 arch/arm64/mm/fault.c:380
 do_bad_area+0x68/0x78 arch/arm64/mm/fault.c:480
 do_tag_check_fault+0x34/0x44 arch/arm64/mm/fault.c:853
 do_mem_abort+0x44/0x94 arch/arm64/mm/fault.c:929
 el1_abort+0x40/0x60 arch/arm64/kernel/entry-common.c:481
 el1h_64_sync_handler+0x50/0xac arch/arm64/kernel/entry-common.c:597
 el1h_64_sync+0x6c/0x70 arch/arm64/kernel/entry.S:591
 __ethtool_get_link_ksettings+0x20/0xb4 net/ethtool/ioctl.c:441 (P)
 ipvlan_ethtool_get_link_ksettings+0x14/0x20 drivers/net/ipvlan/ipvlan_main.c:411
 __ethtool_get_link_ksettings+0x5c/0xb4 net/ethtool/ioctl.c:450
 ib_get_eth_speed+0x84/0x354 drivers/infiniband/core/verbs.c:1996
 rxe_query_port+0xf8/0x1b4 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2148 [inline]
 ib_query_port drivers/infiniband/core/device.c:2180 [inline]
 ib_query_port+0x150/0x200 drivers/infiniband/core/device.c:2170
 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline]
 smc_ib_port_event_work+0x98/0x3cc net/smc/smc_ib.c:388
 process_one_work+0x178/0x2cc kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x250/0x358 kernel/workqueue.c:3400
 kthread+0x130/0x1fc kernel/kthread.c:463
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

Freed by task 1992:
 kasan_save_stack+0x3c/0x64 mm/kasan/common.c:47
 save_stack_info+0x40/0x158 mm/kasan/tags.c:106
 kasan_save_free_info+0x18/0x24 mm/kasan/tags.c:147
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x7c/0x8c mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2422 [inline]
 slab_free mm/slub.c:4695 [inline]
 kfree+0xfc/0x30c mm/slub.c:4894
 kvfree+0x3c/0x4c mm/slub.c:5110
 netdev_release+0x30/0x44 net/core/net-sysfs.c:2250
 device_release+0x34/0x90 drivers/base/core.c:2565
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0xa4/0x114 lib/kobject.c:737
 netdev_run_todo+0x1f0/0x5a4 net/core/dev.c:11513
 rtnl_unlock+0x10/0x1c net/core/rtnetlink.c:157
 default_device_exit_batch+0x320/0x394 net/core/dev.c:12734
 ops_exit_list net/core/net_namespace.c:204 [inline]
 ops_undo_list+0x10c/0x23c net/core/net_namespace.c:251
 cleanup_net+0x1f4/0x3cc net/core/net_namespace.c:682
 process_one_work+0x178/0x2cc kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x250/0x358 kernel/workqueue.c:3400
 kthread+0x130/0x1fc kernel/kthread.c:463
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

The buggy address belongs to the object at fff000000ab47000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 744 bytes inside of
 4096-byte region [fff000000ab47000, fff000000ab48000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xfcf000000ab47000 pfn:0x4ab40
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x1ffc00000000240(workingset|head|node=0|zone=0|lastcpupid=0x7ff|kasantag=0x0)
page_type: f5(slab)
raw: 01ffc00000000240 f1f0000003008000 ffffc1ffc0297010 ffffc1ffc0291e10
raw: fcf000000ab47000 0000000000080003 00000000f5000000 0000000000000000
head: 01ffc00000000240 f1f0000003008000 ffffc1ffc0297010 ffffc1ffc0291e10
head: fcf000000ab47000 0000000000080003 00000000f5000000 0000000000000000
head: 01ffc00000000003 ffffc1ffc02ad001 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 fff000000ab47000: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 fff000000ab47100: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
>fff000000ab47200: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
                                                             ^
 fff000000ab47300: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 fff000000ab47400: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
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