================================================================== BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:444 Read of size 8 at addr ffff8880519ec2f0 b[ 2928.799110][ T5790] Read of size 8 at addr ffff8880519ec2f0 by task kworker/1:5/5790 CPU: 1 UID: 0 PID: 5790 Comm: kworker/1:5 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events smc_ib_port_event_work Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:444 ib_get_eth_speed+0x180/0x800 drivers/infiniband/core/verbs.c:2055 rxe_query_port+0x93/0x3e0 drivers/infiniband/sw/rxe/rxe_verbs.c:62 __ib_query_port drivers/infiniband/core/device.c:2121 [inline] ib_query_port+0x170/0x840 drivers/infiniband/core/device.c:2153 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+0x98b/0x1630 kernel/workqueue.c:3318 process_scheduled_works kernel/workqueue.c:3401 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3482 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5479: 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:5309 [inline] __kvmalloc_node_noprof+0x3c2/0x8e0 mm/slub.c:6807 alloc_netdev_mqs+0xa8/0x1260 net/core/dev.c:12057 rtnl_create_link+0x31f/0xd70 net/core/rtnetlink.c:3713 rtnl_newlink_create+0x277/0xb70 net/core/rtnetlink.c:3895 __rtnl_newlink net/core/rtnetlink.c:4036 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4151 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:7062 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x780/0x920 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:797 __sock_sendmsg net/socket.c:812 [inline] __sys_sendto+0x402/0x590 net/socket.c:2280 __do_sys_sendto net/socket.c:2287 [inline] __se_sys_sendto net/socket.c:2283 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2283 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8426: 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:2700 [inline] slab_free mm/slub.c:6284 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6599 device_release+0xc4/0x1f0 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+0x113d/0x12b0 net/core/dev.c:11758 default_device_exit_batch+0x967/0x9e0 net/core/dev.c:13108 ops_exit_list net/core/net_namespace.c:205 [inline] ops_undo_list+0x52b/0x940 net/core/net_namespace.c:252 cleanup_net+0x56e/0x800 net/core/net_namespace.c:702 process_one_work+0x98b/0x1630 kernel/workqueue.c:3318 process_scheduled_works kernel/workqueue.c:3401 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3482 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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 ffff8880519ec000 which belongs to the cache kmalloc-cg-8k of size 8192 The buggy address is located 752 bytes inside of freed 8192-byte region [ffff8880519ec000, ffff8880519ee000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x519e8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff8880519ea011 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe08640 dead000000000122 0000000000000000 raw: 0000000000000000 0000400000020002 00000000f5000000 ffff8880519ea011 head: 0080000000000040 ffff88813fe08640 dead000000000122 0000000000000000 head: 0000000000000000 0000400000020002 00000000f5000000 ffff8880519ea011 head: 0080000000000003 fffffffffffffe01 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 0xd60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5479, tgid 5479 (syz-executor), ts 2330394198128, free_ts 2323258223742 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x265c/0x26e0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5300 alloc_slab_page mm/slub.c:3289 [inline] allocate_slab+0x74/0x5e0 mm/slub.c:3404 new_slab mm/slub.c:3447 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7216 refill_sheaf mm/slub.c:2827 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4665 alloc_from_pcs mm/slub.c:4763 [inline] slab_alloc_node mm/slub.c:4897 [inline] __do_kmalloc_node mm/slub.c:5308 [inline] __kvmalloc_node_noprof+0x6f4/0x8e0 mm/slub.c:6807 alloc_netdev_mqs+0xa8/0x1260 net/core/dev.c:12057 rtnl_create_link+0x31f/0xd70 net/core/rtnetlink.c:3713 veth_newlink+0x24b/0xb70 drivers/net/veth.c:1848 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3905 __rtnl_newlink net/core/rtnetlink.c:4036 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4151 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:7062 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x780/0x920 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 page last free pid 5346 tgid 5345 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x10af/0x1190 mm/page_alloc.c:2950 __folio_put+0x2eb/0x3a0 mm/swap.c:112 folio_put include/linux/mm.h:2085 [inline] put_page include/linux/mm.h:2154 [inline] put_netmem include/net/netmem.h:394 [inline] skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x544/0xa60 net/core/skbuff.c:1108 skb_release_all net/core/skbuff.c:1189 [inline] kfree_skb_add_bulk net/core/skbuff.c:1263 [inline] kfree_skb_list_reason+0x28b/0x4a0 net/core/skbuff.c:1285 skb_release_data+0x7c2/0xa60 net/core/skbuff.c:1112 skb_release_all net/core/skbuff.c:1189 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1203 kfree_skb_reason include/linux/skbuff.h:1321 [inline] kfree_skb include/linux/skbuff.h:1330 [inline] kcm_release+0x167/0x5d0 net/kcm/kcmsock.c:1695 __sock_release+0xb9/0x250 net/socket.c:726 sock_close+0x1c/0x30 net/socket.c:1529 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x11eb/0x1330 kernel/signal.c:2810 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0xa9/0x680 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880519ec180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880519ec200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880519ec280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880519ec300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880519ec380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================