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BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x190/0x1c0 net/ethtool/ioctl.c:443
Read of size 8 at addr ffff88806a5622f0 by task kworker/0:2/14321

CPU: 0 UID: 0 PID: 14321 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: events smc_ib_port_event_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 __ethtool_get_link_ksettings+0x190/0x1c0 net/ethtool/ioctl.c:443
 __ethtool_get_link_ksettings+0x144/0x1c0 net/ethtool/ioctl.c:450
 ib_get_eth_speed+0x13a/0xb40 drivers/infiniband/core/verbs.c:2054
 rxe_query_port+0x12a/0x330 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2120 [inline]
 ib_query_port drivers/infiniband/core/device.c:2152 [inline]
 ib_query_port+0x441/0x8a0 drivers/infiniband/core/device.c:2142
 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline]
 smc_ib_port_event_work+0x14c/0xbd0 net/smc/smc_ib.c:388
 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
 process_scheduled_works kernel/workqueue.c:3358 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
 kthread+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 5928:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5219 [inline]
 __kvmalloc_node_noprof+0x360/0xa00 mm/slub.c:6711
 alloc_netdev_mqs+0xd7/0x14f0 net/core/dev.c:12012
 rtnl_create_link+0xc13/0xf80 net/core/rtnetlink.c:3648
 rtnl_newlink_create net/core/rtnetlink.c:3830 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
 rtnl_newlink+0x13b8/0x2380 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 __sys_sendto+0x4aa/0x520 net/socket.c:2206
 __do_compat_sys_socketcall net/compat.c:475 [inline]
 __se_compat_sys_socketcall net/compat.c:423 [inline]
 __ia32_compat_sys_socketcall+0x59a/0x770 net/compat.c:423
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 do_int80_emulation+0x141/0x6b0 arch/x86/entry/syscall_32.c:172
 asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:621

Freed by task 15121:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2687 [inline]
 slab_free mm/slub.c:6124 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6442
 device_release+0xa4/0x240 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+0x1f7/0x640 lib/kobject.c:737
 netdev_run_todo+0x817/0x12c0 net/core/dev.c:11713
 rtnl_unlock net/core/rtnetlink.c:157 [inline]
 rtnl_net_unlock include/linux/rtnetlink.h:135 [inline]
 rtnl_dellink+0x481/0xb40 net/core/rtnetlink.c:3578
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa54/0xc30 net/socket.c:2592
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
 __sys_sendmsg+0x170/0x220 net/socket.c:2678
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe3/0x8c0 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff88806a562000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 752 bytes inside of
 freed 4096-byte region [ffff88806a562000, ffff88806a563000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6a560
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801b880280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801b880280 dead000000000122 0000000000000000
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 04fff00000000003 ffffea0001a95801 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5928, tgid 5928 (syz-executor), ts 53766328756, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1888
 prep_new_page mm/page_alloc.c:1896 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3961
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5249
 alloc_slab_page mm/slub.c:3255 [inline]
 allocate_slab mm/slub.c:3444 [inline]
 new_slab+0xa6/0x6d0 mm/slub.c:3502
 refill_objects+0x26b/0x400 mm/slub.c:7134
 refill_sheaf mm/slub.c:2804 [inline]
 alloc_full_sheaf mm/slub.c:2825 [inline]
 __pcs_replace_empty_main+0x19f/0x600 mm/slub.c:4588
 alloc_from_pcs mm/slub.c:4681 [inline]
 slab_alloc_node mm/slub.c:4815 [inline]
 __do_kmalloc_node mm/slub.c:5218 [inline]
 __kmalloc_node_track_caller_noprof+0x694/0x850 mm/slub.c:5327
 kmemdup_noprof+0x29/0x60 mm/util.c:138
 kmemdup_noprof include/linux/fortify-string.h:763 [inline]
 __addrconf_sysctl_register+0xbb/0x360 net/ipv6/addrconf.c:7310
 addrconf_sysctl_register net/ipv6/addrconf.c:7376 [inline]
 addrconf_sysctl_register+0x163/0x200 net/ipv6/addrconf.c:7365
 ipv6_add_dev+0xaf2/0x1520 net/ipv6/addrconf.c:460
 addrconf_notify+0x563/0x19c0 net/ipv6/addrconf.c:3655
 notifier_call_chain+0x99/0x420 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2242
 call_netdevice_notifiers_extack net/core/dev.c:2280 [inline]
 call_netdevice_notifiers net/core/dev.c:2294 [inline]
 register_netdevice+0x16e6/0x2210 net/core/dev.c:11444
 virt_wifi_newlink+0x43e/0x8a0 drivers/net/wireless/virtual/virt_wifi.c:571
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88806a562180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806a562200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88806a562280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff88806a562300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806a562380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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