================================================================== BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:443 Read of size 8 at addr ffff888032e962f0 by task kworker/0:21/23318 CPU: 0 UID: 0 PID: 23318 Comm: kworker/0:21 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events smc_ib_port_event_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:443 ib_get_eth_speed+0x180/0x7f0 drivers/infiniband/core/verbs.c:1999 rxe_query_port+0x93/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:62 __ib_query_port drivers/infiniband/core/device.c:2148 [inline] ib_query_port+0x170/0x830 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:3275 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 17173: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5177 [inline] __kvmalloc_node_noprof+0x528/0x8a0 mm/slub.c:6668 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:12012 rtnl_create_link+0x31f/0xd70 net/core/rtnetlink.c:3648 rtnl_newlink_create+0x277/0xb70 net/core/rtnetlink.c:3830 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x1666/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x709/0x7a0 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2209 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6073: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2670 [inline] slab_free mm/slub.c:6082 [inline] kfree+0x1c1/0x610 mm/slub.c:6399 device_release+0x9e/0x1d0 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+0x228/0x560 lib/kobject.c:737 netdev_run_todo+0xc75/0xde0 net/core/dev.c:11713 default_device_exit_batch+0x986/0xa00 net/core/dev.c:13052 ops_exit_list net/core/net_namespace.c:205 [inline] ops_undo_list+0x52b/0x940 net/core/net_namespace.c:252 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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 ffff888032e96000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 752 bytes inside of freed 4096-byte region [ffff888032e96000, ffff888032e97000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32e90 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888076af7241 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813feb6500 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800040004 00000000f5000000 ffff888076af7241 head: 00fff00000000040 ffff88813feb6500 dead000000000100 dead000000000122 head: 0000000000000000 0000000800040004 00000000f5000000 ffff888076af7241 head: 00fff00000000003 ffffea0000cba401 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 5823, tgid 5823 (syz-executor), ts 95947233353, free_ts 95896970855 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3950 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5245 alloc_slab_page mm/slub.c:3238 [inline] allocate_slab+0x77/0x660 mm/slub.c:3411 new_slab mm/slub.c:3469 [inline] refill_objects+0x331/0x3c0 mm/slub.c:7091 refill_sheaf mm/slub.c:2787 [inline] __pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4536 alloc_from_pcs mm/slub.c:4639 [inline] slab_alloc_node mm/slub.c:4773 [inline] __do_kmalloc_node mm/slub.c:5176 [inline] __kmalloc_noprof+0x474/0x760 mm/slub.c:5189 kmalloc_noprof include/linux/slab.h:966 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379 __addrconf_sysctl_register+0x331/0x4d0 net/ipv6/addrconf.c:7328 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7376 addrconf_notify+0x808/0x1050 net/ipv6/addrconf.c:3788 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2280 [inline] call_netdevice_notifiers net/core/dev.c:2294 [inline] netif_change_name+0x5e5/0x960 net/core/dev.c:1502 do_setlink+0xb6c/0x4590 net/core/rtnetlink.c:3138 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 page last free pid 5818 tgid 5818 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xbf8/0xd70 mm/page_alloc.c:2973 __slab_free+0x263/0x2b0 mm/slub.c:5490 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4459 [inline] slab_alloc_node mm/slub.c:4788 [inline] __do_kmalloc_node mm/slub.c:5176 [inline] __kmalloc_noprof+0x316/0x760 mm/slub.c:5189 kmalloc_noprof include/linux/slab.h:966 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x142/0x860 net/ipv6/route.c:3819 ip6_route_add+0x49/0x1b0 net/ipv6/route.c:3948 addrconf_add_mroute+0x2d1/0x370 net/ipv6/addrconf.c:2552 addrconf_add_dev net/ipv6/addrconf.c:2570 [inline] addrconf_dev_config net/ipv6/addrconf.c:3484 [inline] addrconf_init_auto_addrs+0x4d7/0xa50 net/ipv6/addrconf.c:3572 addrconf_notify+0xb1e/0x1050 net/ipv6/addrconf.c:3745 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2280 [inline] call_netdevice_notifiers net/core/dev.c:2294 [inline] __dev_notify_flags+0x1a9/0x310 net/core/dev.c:9785 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9814 do_setlink+0xf82/0x4590 net/core/rtnetlink.c:3158 Memory state around the buggy address: ffff888032e96180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888032e96200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888032e96280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888032e96300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888032e96380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================