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BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x20/0xf0 net/ethtool/ioctl.c:461
Read at addr fcf0000013698ad9 by task kworker/0:2/16165
Pointer tag: [fc], memory tag: [fe]

CPU: 0 UID: 0 PID: 16165 Comm: kworker/0:2 Tainted: G        W           syzkaller #0 PREEMPT 
Tainted: [W]=WARN
Hardware name: linux,dummy-virt (DT)
Workqueue: events smc_ib_port_event_work
Call trace:
 dump_backtrace arch/arm64/kernel/stacktrace.c:498 [inline] (C)
 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x60/0x80 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x1c4/0x4b0 mm/kasan/report.c:482
 kasan_report+0x84/0xac mm/kasan/report.c:595
 report_tag_fault arch/arm64/mm/fault.c:368 [inline]
 do_tag_recovery arch/arm64/mm/fault.c:380 [inline]
 __do_kernel_fault+0x1b4/0x220 arch/arm64/mm/fault.c:424
 do_bad_area+0x68/0x80 arch/arm64/mm/fault.c:529
 do_tag_check_fault+0x34/0x44 arch/arm64/mm/fault.c:909
 do_mem_abort+0x40/0x90 arch/arm64/mm/fault.c:985
 el1_abort+0x44/0x64 arch/arm64/kernel/entry-common.c:342
 el1h_64_sync_handler+0x50/0xac arch/arm64/kernel/entry-common.c:469
 el1h_64_sync+0x6c/0x70 arch/arm64/kernel/entry.S:585
 __ethtool_get_link_ksettings+0x20/0xf0 net/ethtool/ioctl.c:461 (P)
 ipvlan_ethtool_get_link_ksettings+0x14/0x20 drivers/net/ipvlan/ipvlan_main.c:467
 netif_get_link_ksettings+0x60/0xc8 net/ethtool/ioctl.c:451
 __ethtool_get_link_ksettings+0x84/0xf0 net/ethtool/ioctl.c:464
 ib_get_eth_speed+0x88/0x40c drivers/infiniband/core/verbs.c:2061
 rxe_query_port+0x88/0x1a0 drivers/infiniband/sw/rxe/rxe_verbs.c:56
 __ib_query_port drivers/infiniband/core/device.c:2304 [inline]
 ib_query_port drivers/infiniband/core/device.c:2336 [inline]
 ib_query_port+0x14c/0x200 drivers/infiniband/core/device.c:2326
 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline]
 smc_ib_port_event_work+0x8c/0x3dc net/smc/smc_ib.c:388
 process_one_work+0x1ac/0x320 kernel/workqueue.c:3387
 process_scheduled_works kernel/workqueue.c:3470 [inline]
 worker_thread+0x184/0x2f4 kernel/workqueue.c:3551
 kthread+0x118/0x130 kernel/kthread.c:436
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854

Freed by task 2252:
 kasan_save_stack+0x3c/0x64 mm/kasan/common.c:57
 save_stack_info+0x40/0x160 mm/kasan/tags.c:106
 kasan_save_free_info+0x18/0x40 mm/kasan/tags.c:147
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0xe8/0x160 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6499 [inline]
 kfree+0x150/0x420 mm/slub.c:6792
 kvfree+0x3c/0x4c mm/slub.c:7054
 netdev_release+0x30/0x50 net/core/net-sysfs.c:2231
 device_release+0x3c/0x98 drivers/base/core.c:2640
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0xa4/0x120 lib/kobject.c:737
 netdev_run_todo+0x24c/0x5f0 net/core/dev.c:11818
 rtnl_unlock+0x10/0x1c net/core/rtnetlink.c:157
 default_device_exit_batch+0x2e0/0x334 net/core/dev.c:13289
 ops_exit_list net/core/net_namespace.c:206 [inline]
 ops_undo_list+0x114/0x244 net/core/net_namespace.c:253
 cleanup_net+0x210/0x40c net/core/net_namespace.c:706
 process_one_work+0x1ac/0x320 kernel/workqueue.c:3387
 process_scheduled_works kernel/workqueue.c:3470 [inline]
 worker_thread+0x184/0x2f4 kernel/workqueue.c:3551
 kthread+0x118/0x130 kernel/kthread.c:436
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854

The buggy address belongs to the object at fff0000013698000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 2777 bytes inside of
 4096-byte region [fff0000013698000, fff0000013699000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xfcf0000013698000 pfn:0x53698
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:f4f000000a32af01
flags: 0x1ffc00000000240(workingset|head|node=0|zone=0|lastcpupid=0x7ff|kasantag=0x0)
page_type: f5(slab)
raw: 01ffc00000000240 f0f0000003408000 ffffc1ffc04e8e10 ffffc1ffc04e0010
raw: fcf0000013698000 0000000200080004 00000000f5000000 f4f000000a32af01
head: 01ffc00000000240 f0f0000003408000 ffffc1ffc04e8e10 ffffc1ffc04e0010
head: fcf0000013698000 0000000200080004 00000000f5000000 f4f000000a32af01
head: 01ffc00000000003 ffffc1ffc04da601 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 fff0000013698800: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 fff0000013698900: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
>fff0000013698a00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
                                                          ^
 fff0000013698b00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 fff0000013698c00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
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