================================================================== BUG: KASAN: slab-use-after-free in dev_hard_header include/linux/netdevice.h:3416 [inline] BUG: KASAN: slab-use-after-free in ipvlan_hard_header+0xa2/0x120 drivers/net/ipvlan/ipvlan_main.c:383 Read of size 8 at addr ffff888059b56010 by task kworker/u8:32/7144 CPU: 0 UID: 0 PID: 7144 Comm: kworker/u8:32 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: netns cleanup_net 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 dev_hard_header include/linux/netdevice.h:3416 [inline] ipvlan_hard_header+0xa2/0x120 drivers/net/ipvlan/ipvlan_main.c:383 dev_hard_header include/linux/netdevice.h:3419 [inline] tipc_l2_send_msg+0x31c/0x400 net/tipc/bearer.c:514 tipc_bearer_xmit_skb+0x2b3/0x400 net/tipc/bearer.c:575 tipc_disc_timeout+0x580/0x6d0 net/tipc/discover.c:338 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x283/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:873 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1169 [inline] RIP: 0010:unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 Code: d2 0d 01 48 c7 c7 a0 60 48 8b be 66 03 00 00 48 c7 c2 40 61 48 8b e8 06 c4 29 00 48 c7 c7 60 a8 d3 8d 4c 89 fe e8 e7 a9 29 00 82 59 33 00 89 d8 48 81 c4 98 00 00 00 5b 41 5c 41 5d 41 5e 41 RSP: 0018:ffffc9001bd76ef8 EFLAGS: 00000286 RAX: 4b692ed470039d00 RBX: ffffffff8fed2601 RCX: 4b692ed470039d00 RDX: 0000000000000005 RSI: ffffffff8d6ef4b7 RDI: ffffffff8b9ec4e0 RBP: dffffc0000000000 R08: ffffc9001bd77100 R09: 0000000000000000 R10: ffffc9001bd77018 R11: fffff520037aee05 R12: ffffc9001bd77110 R13: ffffc9001bd70000 R14: ffffc9001bd76fc8 R15: ffffffff81725d05 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3123 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3243 kernfs_put+0x19e/0x480 fs/kernfs/dir.c:591 kernfs_remove_by_name_ns+0xb7/0x130 fs/kernfs/dir.c:1718 kernfs_remove_by_name include/linux/kernfs.h:633 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xfc/0x2c0 fs/sysfs/group.c:322 sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:346 device_remove_groups drivers/base/core.c:2843 [inline] device_remove_attrs+0x1aa/0x260 drivers/base/core.c:2973 device_del+0x509/0x8e0 drivers/base/core.c:3877 unregister_netdevice_many_notify+0x1a6b/0x1ff0 net/core/dev.c:12289 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248 cleanup_net+0x4d8/0x820 net/core/net_namespace.c:695 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5844: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4376 [inline] __kvmalloc_node_noprof+0x30d/0x5f0 mm/slub.c:5067 alloc_netdev_mqs+0xa3/0x11b0 net/core/dev.c:11900 rtnl_create_link+0x31f/0xd10 net/core/rtnetlink.c:3641 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3823 __rtnl_newlink net/core/rtnetlink.c:3950 [inline] rtnl_newlink+0x16e4/0x1c80 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6954 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:742 __sys_sendto+0x3bd/0x520 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2247 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 14049: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x18e/0x440 mm/slub.c:4894 device_release+0x9c/0x1c0 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+0x22b/0x480 lib/kobject.c:737 netdev_run_todo+0xd2e/0xea0 net/core/dev.c:11601 rtnl_unlock net/core/rtnetlink.c:157 [inline] rtnl_net_unlock include/linux/rtnetlink.h:135 [inline] rtnl_dellink+0x5aa/0x700 net/core/rtnetlink.c:3571 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6954 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x830 net/socket.c:2630 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684 __sys_sendmsg net/socket.c:2716 [inline] __do_sys_sendmsg net/socket.c:2721 [inline] __se_sys_sendmsg net/socket.c:2719 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888059b56000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 16 bytes inside of freed 4096-byte region [ffff888059b56000, ffff888059b57000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x59b50 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a04b500 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a04b500 dead000000000122 0000000000000000 head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea000166d401 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 5834, tgid 5834 (syz-executor), ts 80340526115, free_ts 22942423678 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2660 new_slab mm/slub.c:2714 [inline] ___slab_alloc+0xbeb/0x1420 mm/slub.c:3901 __slab_alloc mm/slub.c:3992 [inline] __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __kmalloc_cache_noprof+0x296/0x3d0 mm/slub.c:4402 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:362 [inline] ipv6_add_dev+0x6ca/0x1370 net/ipv6/addrconf.c:413 addrconf_notify+0x794/0x1010 net/ipv6/addrconf.c:3650 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] register_netdevice+0x1608/0x1ae0 net/core/dev.c:11332 virt_wifi_newlink+0x428/0x860 drivers/net/wireless/virtual/virt_wifi.c:571 rtnl_newlink_create+0x30d/0xb00 net/core/rtnetlink.c:3833 __rtnl_newlink net/core/rtnetlink.c:3950 [inline] rtnl_newlink+0x16e4/0x1c80 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6954 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 __free_pages mm/page_alloc.c:5260 [inline] free_contig_range+0x1bd/0x4a0 mm/page_alloc.c:7091 destroy_args+0x69/0x660 mm/debug_vm_pgtable.c:958 debug_vm_pgtable+0x39f/0x3b0 mm/debug_vm_pgtable.c:1345 do_one_initcall+0x233/0x820 init/main.c:1271 do_initcall_level+0x104/0x190 init/main.c:1333 do_initcalls+0x59/0xa0 init/main.c:1349 kernel_init_freeable+0x334/0x4b0 init/main.c:1581 kernel_init+0x1d/0x1d0 init/main.c:1471 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888059b55f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888059b55f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888059b56000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888059b56080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888059b56100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: d2 0d 01 48 c7 c7 rorb %cl,-0x3838b7ff(%rip) # 0xc7c74807 6: a0 60 48 8b be 66 03 movabs 0x366be8b4860,%al d: 00 00 f: 48 c7 c2 40 61 48 8b mov $0xffffffff8b486140,%rdx 16: e8 06 c4 29 00 call 0x29c421 1b: 48 c7 c7 60 a8 d3 8d mov $0xffffffff8dd3a860,%rdi 22: 4c 89 fe mov %r15,%rsi 25: e8 e7 a9 29 00 call 0x29aa11 * 2a: e8 82 59 33 00 call 0x3359b1 <-- trapping instruction 2f: 89 d8 mov %ebx,%eax 31: 48 81 c4 98 00 00 00 add $0x98,%rsp 38: 5b pop %rbx 39: 41 5c pop %r12 3b: 41 5d pop %r13 3d: 41 5e pop %r14 3f: 41 rex.B