================================================================== BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:444 Read of size 8 at addr ffff8880339fc2f0 by task kworker/1:5/5724 CPU: 1 UID: 0 PID: 5724 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 04/18/2026 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 5618: 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:12063 rtnl_create_link+0x31f/0xd70 net/core/rtnetlink.c:3685 rtnl_newlink_create+0x277/0xb70 net/core/rtnetlink.c:3867 __rtnl_newlink net/core/rtnetlink.c:4008 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4123 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:7010 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551 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:1895 sock_sendmsg_nosec+0x112/0x150 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+0x15f/0x560 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 3375: 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+0xfb6/0x1130 net/core/dev.c:11764 default_device_exit_batch+0x967/0x9e0 net/core/dev.c:13116 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 ffff8880339fc000 which belongs to the cache kmalloc-cg-8k of size 8192 The buggy address is located 752 bytes inside of freed 8192-byte region [ffff8880339fc000, ffff8880339fe000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x339f8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe05640 dead000000000122 0000000000000000 raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe05640 dead000000000122 0000000000000000 head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000 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 5614, tgid 5614 (syz-executor), ts 93683226562, free_ts 70189675645 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1866 prep_new_page mm/page_alloc.c:1874 [inline] get_page_from_freelist+0x265c/0x26e0 mm/page_alloc.c:3953 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5296 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:7226 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:12063 rtnl_create_link+0x31f/0xd70 net/core/rtnetlink.c:3685 rtnl_newlink_create+0x277/0xb70 net/core/rtnetlink.c:3867 __rtnl_newlink net/core/rtnetlink.c:4008 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4123 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:7010 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551 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:1895 sock_sendmsg_nosec+0x112/0x150 net/socket.c:797 page last free pid 5462 tgid 5462 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1413 [inline] __free_frozen_pages+0x10af/0x1190 mm/page_alloc.c:2957 __slab_free+0x252/0x2a0 mm/slub.c:5646 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 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:4583 [inline] slab_alloc_node mm/slub.c:4912 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4919 vm_area_alloc+0x24/0x140 mm/vma_init.c:32 do_brk_flags+0x483/0xae0 mm/vma.c:2924 __do_sys_brk mm/mmap.c:195 [inline] __se_sys_brk+0x9d8/0xba0 mm/mmap.c:116 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880339fc180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880339fc200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880339fc280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880339fc300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880339fc380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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