================================================================== BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:444 Read of size 8 at addr ffff88801f69c2f0 by task kworker/1:12/14278 CPU: 1 UID: 0 PID: 14278 Comm: kworker/1:12 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: infiniband ib_cache_event_task 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:444 ib_get_eth_speed+0x180/0x7f0 drivers/infiniband/core/verbs.c:2054 rxe_query_port+0x93/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:62 __ib_query_port drivers/infiniband/core/device.c:2121 [inline] ib_query_port+0x170/0x830 drivers/infiniband/core/device.c:2153 ib_cache_update+0x1ba/0xc70 drivers/infiniband/core/cache.c:1465 ib_cache_event_task+0xe0/0x1d0 drivers/infiniband/core/cache.c:1544 process_one_work kernel/workqueue.c:3288 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 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 27195: 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:5260 [inline] __kvmalloc_node_noprof+0x528/0x8a0 mm/slub.c:6752 alloc_netdev_mqs+0xa6/0x11b0 net/core/dev.c:12076 rtnl_create_link+0x31f/0xd70 net/core/rtnetlink.c:3670 rtnl_newlink_create+0x277/0xb70 net/core/rtnetlink.c:3852 __rtnl_newlink net/core/rtnetlink.c:3993 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4108 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6994 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x672/0x710 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 1252: 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:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1c1/0x620 mm/slub.c:6483 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+0xc75/0xde0 net/core/dev.c:11777 rtnl_unlock net/core/rtnetlink.c:157 [inline] rtnl_net_unlock include/linux/rtnetlink.h:135 [inline] rtnl_dellink+0x6a7/0x820 net/core/rtnetlink.c:3600 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6994 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88801f69c000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 752 bytes inside of freed 4096-byte region [ffff88801f69c000, ffff88801f69d000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f698 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888035ec9ac1 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fe44500 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800040004 00000000f5000000 ffff888035ec9ac1 head: 00fff00000000040 ffff88813fe44500 dead000000000100 dead000000000122 head: 0000000000000000 0000000800040004 00000000f5000000 ffff888035ec9ac1 head: 00fff00000000003 ffffea00007da601 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 5822, tgid 5822 (syz-executor), ts 90717553409, free_ts 90688386020 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab+0x77/0x660 mm/slub.c:3481 new_slab mm/slub.c:3539 [inline] refill_objects+0x331/0x3c0 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5375 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:362 [inline] ipv6_add_dev+0x6aa/0x13a0 net/ipv6/addrconf.c:413 ipv6_find_idev+0xb1/0x1c0 net/ipv6/addrconf.c:498 inet6_rtm_newaddr+0x7d5/0xe30 net/ipv6/addrconf.c:5049 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6994 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x672/0x710 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2268 page last free pid 5822 tgid 5822 stack trace: create_dummy_stack mm/page_owner.c:103 [inline] register_dummy_stack+0x98/0x100 mm/page_owner.c:109 init_page_owner+0x2e/0x600 mm/page_owner.c:127 invoke_init_callbacks mm/page_ext.c:152 [inline] page_ext_init+0x500/0x540 mm/page_ext.c:490 mm_core_init+0x51/0x70 mm/mm_init.c:2735 Memory state around the buggy address: ffff88801f69c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801f69c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801f69c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801f69c300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801f69c380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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