==================================================================
BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x1bf/0x200 net/ethtool/ioctl.c:443
Read of size 8 at addr ffff888024fa62e8 by task kworker/1:1/44

CPU: 1 UID: 0 PID: 44 Comm: kworker/1:1 Not tainted 6.16.0-rc3-syzkaller-00042-g78f4e737a53e #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events smc_ib_port_event_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xcd/0x680 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 __ethtool_get_link_ksettings+0x1bf/0x200 net/ethtool/ioctl.c:443
 __ethtool_get_link_ksettings+0x145/0x200 net/ethtool/ioctl.c:450
 ib_get_eth_speed+0x122/0xb50 drivers/infiniband/core/verbs.c:1996
 rxe_query_port+0x108/0x330 drivers/infiniband/sw/rxe/rxe_verbs.c:62
 __ib_query_port drivers/infiniband/core/device.c:2111 [inline]
 ib_query_port drivers/infiniband/core/device.c:2143 [inline]
 ib_query_port+0x43e/0x8a0 drivers/infiniband/core/device.c:2133
 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline]
 smc_ib_port_event_work+0x12f/0xbf0 net/smc/smc_ib.c:388
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 5814:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4328 [inline]
 __kvmalloc_node_noprof+0x27b/0x620 mm/slub.c:5015
 alloc_netdev_mqs+0xd2/0x1570 net/core/dev.c:11711
 rtnl_create_link+0xc08/0xf90 net/core/rtnetlink.c:3631
 rtnl_newlink_create net/core/rtnetlink.c:3813 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3940 [inline]
 rtnl_newlink+0xb69/0x2000 net/core/rtnetlink.c:4055
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 __sys_sendto+0x4a0/0x520 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2183
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 1142:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kfree+0x2b4/0x4d0 mm/slub.c:4842
 device_release+0xa4/0x240 drivers/base/core.c:2568
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1e7/0x5a0 lib/kobject.c:737
 netdev_run_todo+0x7e9/0x1320 net/core/dev.c:11412
 default_device_exit_batch+0x858/0xaf0 net/core/dev.c:12645
 ops_exit_list net/core/net_namespace.c:206 [inline]
 ops_undo_list+0x363/0xab0 net/core/net_namespace.c:253
 cleanup_net+0x408/0x890 net/core/net_namespace.c:686
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff888024fa6000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 744 bytes inside of
 freed 4096-byte region [ffff888024fa6000, ffff888024fa7000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24fa0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b84b500 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b84b500 dead000000000122 0000000000000000
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea000093e801 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 5811, tgid 5811 (syz-executor), ts 72391445794, free_ts 72343610598
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2451 [inline]
 allocate_slab mm/slub.c:2619 [inline]
 new_slab+0x23b/0x330 mm/slub.c:2673
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4354
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 snmp6_alloc_dev net/ipv6/addrconf.c:360 [inline]
 ipv6_add_dev+0x6b7/0x15f0 net/ipv6/addrconf.c:411
 addrconf_notify+0x53e/0x19e0 net/ipv6/addrconf.c:3654
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 register_netdevice+0x182e/0x2270 net/core/dev.c:11143
 macvlan_common_newlink+0x10e7/0x1a20 drivers/net/macvlan.c:1540
 rtnl_newlink_create net/core/rtnetlink.c:3823 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3940 [inline]
 rtnl_newlink+0xc42/0x2000 net/core/rtnetlink.c:4055
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944
page last free pid 5825 tgid 5825 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 __kmalloc_cache_noprof+0x1f1/0x3e0 mm/slub.c:4354
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 ref_tracker_alloc+0x18e/0x5b0 lib/ref_tracker.c:203
 __netdev_tracker_alloc include/linux/netdevice.h:4341 [inline]
 netdev_hold include/linux/netdevice.h:4370 [inline]
 netdev_hold include/linux/netdevice.h:4365 [inline]
 register_netdevice+0x1689/0x2270 net/core/dev.c:11129
 macvlan_common_newlink+0x10e7/0x1a20 drivers/net/macvlan.c:1540
 macvtap_newlink drivers/net/macvtap.c:108 [inline]
 macvtap_newlink+0x17a/0x240 drivers/net/macvtap.c:80
 rtnl_newlink_create net/core/rtnetlink.c:3823 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3940 [inline]
 rtnl_newlink+0xc42/0x2000 net/core/rtnetlink.c:4055
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 __sys_sendto+0x4a0/0x520 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2183

Memory state around the buggy address:
 ffff888024fa6180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888024fa6200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888024fa6280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff888024fa6300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888024fa6380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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