================================================================== BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:443 Read of size 8 at addr ffff88803dbc22e8 by task kworker/1:3/5821 CPU: 1 UID: 0 PID: 5821 Comm: kworker/1:3 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:443 ib_get_eth_speed+0x15e/0x7b0 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+0x16f/0x940 net/smc/smc_ib.c:388 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 18429: 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:397 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kvmalloc_node_noprof+0x408/0x940 mm/slub.c:7136 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:11997 rtnl_create_link+0x31f/0xcf0 net/core/rtnetlink.c:3648 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3830 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x846/0xa10 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 __sys_sendto+0x3c7/0x520 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+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15945: 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:584 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:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x1bd/0x900 mm/slub.c:6878 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+0x228/0x570 lib/kobject.c:737 netdev_run_todo+0xd2c/0xea0 net/core/dev.c:11698 default_device_exit_batch+0x969/0x9e0 net/core/dev.c:13037 ops_exit_list net/core/net_namespace.c:205 [inline] ops_undo_list+0x525/0x990 net/core/net_namespace.c:252 cleanup_net+0x4de/0x7b0 net/core/net_namespace.c:696 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff88803dbc2000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 744 bytes inside of freed 4096-byte region [ffff88803dbc2000, ffff88803dbc3000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3dbc0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff8880304055c1 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813ff30500 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000000f5000000 ffff8880304055c1 head: 0080000000000040 ffff88813ff30500 dead000000000122 0000000000000000 head: 0000000000000000 0000000000040004 00000000f5000000 ffff8880304055c1 head: 0080000000000003 ffffea0000f6f001 00000000ffffffff 00000000ffffffff head: 0000000000000000 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 18426, tgid 18426 (syz-executor), ts 2340309394005, free_ts 2254566440054 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xb10/0x13e0 mm/slub.c:4656 __slab_alloc+0xc6/0x1f0 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x15f/0x7e0 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379 __addrconf_sysctl_register+0x328/0x4c0 net/ipv6/addrconf.c:7323 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7371 ipv6_add_dev+0xd64/0x1400 net/ipv6/addrconf.c:460 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3650 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline] call_netdevice_notifiers net/core/dev.c:2282 [inline] register_netdevice+0x15d2/0x1a80 net/core/dev.c:11429 register_vlan_dev+0x38b/0x800 net/8021q/vlan.c:179 page last free pid 5791 tgid 5791 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xfe1/0x1170 mm/page_alloc.c:2943 discard_slab mm/slub.c:3346 [inline] __put_partials+0x149/0x170 mm/slub.c:3886 __slab_free+0x2af/0x330 mm/slub.c:5952 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:349 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_lru_noprof+0x193/0x6c0 mm/slub.c:5282 alloc_inode+0xb8/0x1b0 fs/inode.c:348 new_inode_pseudo include/linux/fs.h:2964 [inline] get_pipe_inode fs/pipe.c:888 [inline] create_pipe_files+0x51/0x7e0 fs/pipe.c:928 __do_pipe_flags+0x46/0x1f0 fs/pipe.c:990 do_pipe2+0x9c/0x170 fs/pipe.c:1038 __do_sys_pipe2 fs/pipe.c:1056 [inline] __se_sys_pipe2 fs/pipe.c:1054 [inline] __x64_sys_pipe2+0x5a/0x70 fs/pipe.c:1054 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88803dbc2180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803dbc2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803dbc2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803dbc2300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803dbc2380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================