================================================================== BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:443 Read of size 8 at addr ffff8880249142e8 by task kworker/0:7/5967 CPU: 0 UID: 0 PID: 5967 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events smc_ib_port_event_work Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __ethtool_get_link_ksettings+0x6e/0x190 net/ethtool/ioctl.c:443 ib_get_eth_speed+0x15e/0x7c0 drivers/infiniband/core/verbs.c:1996 rxe_query_port+0x93/0x3b0 drivers/infiniband/sw/rxe/rxe_verbs.c:62 __ib_query_port drivers/infiniband/core/device.c:2148 [inline] ib_query_port+0x170/0x840 drivers/infiniband/core/device.c:2180 smc_ib_remember_port_attr net/smc/smc_ib.c:364 [inline] smc_ib_port_event_work+0x15a/0x940 net/smc/smc_ib.c:388 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 19358: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5602 [inline] __kvmalloc_node_noprof+0x5cd/0x910 mm/slub.c:7028 alloc_netdev_mqs+0xa8/0x1200 net/core/dev.c:11902 rtnl_create_link+0x31f/0xd10 net/core/rtnetlink.c:3633 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3815 __rtnl_newlink net/core/rtnetlink.c:3942 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6946 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 __sys_sendto+0x3bd/0x520 net/socket.c:2231 __do_sys_sendto net/socket.c:2238 [inline] __se_sys_sendto net/socket.c:2234 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2234 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 1118: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2507 [inline] slab_free mm/slub.c:6557 [inline] kfree+0x19a/0x6d0 mm/slub.c:6765 device_release+0x9c/0x1c0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22b/0x480 lib/kobject.c:737 netdev_run_todo+0xeb3/0x1020 net/core/dev.c:11603 default_device_exit_batch+0x81e/0x890 net/core/dev.c:12829 ops_exit_list net/core/net_namespace.c:205 [inline] ops_undo_list+0x525/0x990 net/core/net_namespace.c:252 cleanup_net+0x4d8/0x810 net/core/net_namespace.c:701 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888024914000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 744 bytes inside of freed 4096-byte region [ffff888024914000, ffff888024915000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24910 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888064899ec1 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b04b500 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000000f5000000 ffff888064899ec1 head: 00fff00000000040 ffff88801b04b500 dead000000000122 0000000000000000 head: 0000000000000000 0000000000040004 00000000f5000000 ffff888064899ec1 head: 00fff00000000003 ffffea0000924401 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 7421, tgid 7421 (kworker/u8:12), ts 626722718961, free_ts 626059972995 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3869 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5159 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3023 [inline] allocate_slab+0x96/0x3a0 mm/slub.c:3196 new_slab mm/slub.c:3250 [inline] ___slab_alloc+0xe94/0x1920 mm/slub.c:4626 __slab_alloc+0x65/0x100 mm/slub.c:4745 __slab_alloc_node mm/slub.c:4821 [inline] slab_alloc_node mm/slub.c:5232 [inline] __do_kmalloc_node mm/slub.c:5601 [inline] __kmalloc_node_track_caller_noprof+0x5c7/0x800 mm/slub.c:5711 kmemdup_noprof+0x2b/0x70 mm/util.c:138 kmemdup_noprof include/linux/fortify-string.h:765 [inline] __addrconf_sysctl_register+0x9e/0x4c0 net/ipv6/addrconf.c:7305 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7371 ipv6_add_dev+0xd64/0x1380 net/ipv6/addrconf.c:460 addrconf_notify+0x794/0x1010 net/ipv6/addrconf.c:3650 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] register_netdevice+0x1608/0x1ae0 net/core/dev.c:11325 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1034 [inline] nsim_create+0xae8/0xf10 drivers/net/netdevsim/netdev.c:1105 page last free pid 19358 tgid 19358 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2906 discard_slab mm/slub.c:3294 [inline] __put_partials+0x146/0x170 mm/slub.c:3841 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3916 __slab_free+0x2b9/0x390 mm/slub.c:5881 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4945 [inline] slab_alloc_node mm/slub.c:5244 [inline] kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5296 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1377 [inline] nlmsg_new include/net/netlink.h:1055 [inline] netlink_ack+0x146/0xa50 net/netlink/af_netlink.c:2489 netlink_rcv_skb+0x28c/0x470 net/netlink/af_netlink.c:2558 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 __sys_sendto+0x3bd/0x520 net/socket.c:2231 __do_sys_sendto net/socket.c:2238 [inline] __se_sys_sendto net/socket.c:2234 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2234 Memory state around the buggy address: ffff888024914180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888024914200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888024914280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888024914300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888024914380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================