================================================================== BUG: KASAN: slab-use-after-free in __ethtool_get_link_ksettings+0x5e/0x170 net/ethtool/ioctl.c:443 Read of size 8 at addr ffff88802fd162e8 by task kworker/1:7/6086 CPU: 1 UID: 0 PID: 6086 Comm: kworker/1:7 Not tainted syzkaller #0 PREEMPT(full) 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+0x189/0x250 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:1996 rxe_query_port+0x93/0x3b0 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: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+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 5974: 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:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5652 [inline] __kvmalloc_node_noprof+0x5c9/0x910 mm/slub.c:7128 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+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:733 __sys_sendto+0x3bd/0x520 net/socket.c:2222 __do_sys_sendto net/socket.c:2229 [inline] __se_sys_sendto net/socket.c:2225 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2225 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 70: 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:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] 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:6663 [inline] kfree+0x1c0/0x660 mm/slub.c:6871 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+0x228/0x480 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+0x4d8/0x7a0 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+0x599/0xb30 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 ffff88802fd16000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 744 bytes inside of freed 4096-byte region [ffff88802fd16000, ffff88802fd17000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2fd10 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888078c972c1 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a030500 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000000f5000000 ffff888078c972c1 head: 00fff00000000040 ffff88801a030500 dead000000000122 0000000000000000 head: 0000000000000000 0000000000040004 00000000f5000000 ffff888078c972c1 head: 00fff00000000003 ffffea0000bf4401 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 5982, tgid 5982 (syz-executor), ts 196407221200, free_ts 196382838163 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 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+0xf2b/0x1960 mm/slub.c:4651 __slab_alloc+0x65/0x100 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5246 [inline] __kmalloc_cache_noprof+0x411/0x6f0 mm/slub.c:5766 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:362 [inline] ipv6_add_dev+0x6aa/0x1330 net/ipv6/addrconf.c:413 addrconf_notify+0x771/0xfe0 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+0x15bd/0x1a70 net/core/dev.c:11429 hsr_dev_finalize+0x641/0xaa0 net/hsr/hsr_device.c:782 hsr_newlink+0x8ad/0x9f0 net/hsr/hsr_netlink.c:128 rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3840 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x16e7/0x1c90 net/core/rtnetlink.c:4072 page last free pid 5195 tgid 5195 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2901 discard_slab mm/slub.c:3346 [inline] __put_partials+0x146/0x170 mm/slub.c:3886 put_cpu_partial+0x1f2/0x2d0 mm/slub.c:3961 __slab_free+0x288/0x2a0 mm/slub.c:5947 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:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4948 [inline] slab_alloc_node mm/slub.c:5258 [inline] kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5310 __alloc_skb+0x255/0x430 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6712 sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2995 unix_dgram_sendmsg+0x454/0x1840 net/unix/af_unix.c:2130 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:733 __sys_sendto+0x3bd/0x520 net/socket.c:2222 __do_sys_sendto net/socket.c:2229 [inline] __se_sys_sendto net/socket.c:2225 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2225 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff88802fd16180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802fd16200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802fd16280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802fd16300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802fd16380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================