==================================================================
BUG: KASAN: slab-use-after-free in fib_rules_lookup+0x15e/0xeb0 net/core/fib_rules.c:321
Read of size 8 at addr ffff88802b94ec80 by task dhcpcd/8086

CPU: 1 UID: 101 PID: 8086 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 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
 fib_rules_lookup+0x15e/0xeb0 net/core/fib_rules.c:321
 __fib_lookup+0x106/0x210 net/ipv4/fib_rules.c:96
 ip_route_input_slow net/ipv4/route.c:2353 [inline]
 ip_route_input_rcu+0x19ee/0x3190 net/ipv4/route.c:2540
 ip_route_input_noref+0x17c/0x270 net/ipv4/route.c:2551
 arp_process+0xaab/0x18c0 net/ipv4/arp.c:841
 NF_HOOK+0x33a/0x3c0 include/linux/netfilter.h:-1
 __netif_receive_skb_one_core net/core/dev.c:6205 [inline]
 __netif_receive_skb net/core/dev.c:6318 [inline]
 process_backlog+0x5d6/0xc50 net/core/dev.c:6669
 __napi_poll+0xae/0x550 net/core/dev.c:7728
 napi_poll net/core/dev.c:7791 [inline]
 net_rx_action+0x621/0xd70 net/core/dev.c:7948
 handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:626
 __do_softirq kernel/softirq.c:660 [inline]
 __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:914 [inline]
 __dev_queue_xmit+0x1f31/0x3890 net/core/dev.c:4908
 packet_snd net/packet/af_packet.c:3082 [inline]
 packet_sendmsg+0x3daf/0x5060 net/packet/af_packet.c:3114
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:785
 __sock_sendmsg net/socket.c:800 [inline]
 sock_write_iter+0x2e4/0x3f0 net/socket.c:1256
 do_iter_readv_writev+0x624/0x8d0 fs/read_write.c:-1
 vfs_writev+0x34c/0x990 fs/read_write.c:1058
 do_writev+0x15a/0x2e0 fs/read_write.c:1104
 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
RIP: 0033:0x7f330535e407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffd1fc8c560 EFLAGS: 00000202 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f33052d4780 RCX: 00007f330535e407
RDX: 0000000000000002 RSI: 00007ffd1fc8c5c0 RDI: 0000000000000003
RBP: 000000000000005c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffd1fc8c600
R13: 000055686a3a3080 R14: 00007ffd1fc8c650 R15: 00007ffd1fc9c820
 </TASK>

Allocated by task 5608:
 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:5360 [inline]
 __kmalloc_node_track_caller_noprof+0x57f/0x7c0 mm/slub.c:5495
 kmemdup_noprof+0x2b/0x70 mm/util.c:138
 kmemdup_noprof include/linux/fortify-string.h:763 [inline]
 fib_rules_register+0x2f/0x400 net/core/fib_rules.c:170
 fib4_rules_init+0x21/0x160 net/ipv4/fib_rules.c:508
 ip_fib_net_init net/ipv4/fib_frontend.c:1578 [inline]
 fib_net_init+0x17a/0x3e0 net/ipv4/fib_frontend.c:1628
 ops_init+0x35d/0x5d0 net/core/net_namespace.c:137
 setup_net+0x118/0x350 net/core/net_namespace.c:446
 copy_net_ns+0x4f9/0x720 net/core/net_namespace.c:579
 create_new_namespaces+0x3f0/0x6b0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234
 ksys_unshare+0x57d/0xa00 kernel/fork.c:3267
 __do_sys_unshare kernel/fork.c:3341 [inline]
 __se_sys_unshare kernel/fork.c:3339 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3339
 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 5875:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 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:2703 [inline]
 slab_free_freelist_hook mm/slub.c:2732 [inline]
 slab_free_bulk mm/slub.c:6437 [inline]
 kmem_cache_free_bulk+0x309/0x1260 mm/slub.c:7174
 kfree_bulk include/linux/slab.h:891 [inline]
 kvfree_rcu_bulk+0xc6/0x190 mm/slab_common.c:1502
 kfree_rcu_work+0xe8/0x160 mm/slab_common.c:1580
 process_one_work+0x93a/0x12b0 kernel/workqueue.c:3326
 process_scheduled_works kernel/workqueue.c:3409 [inline]
 worker_thread+0xb05/0x10d0 kernel/workqueue.c:3490
 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

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
 kvfree_call_rcu+0x90/0x3c0 mm/slab_common.c:1970
 ops_exit_rtnl_list net/core/net_namespace.c:181 [inline]
 ops_undo_list+0x319/0x8d0 net/core/net_namespace.c:248
 cleanup_net+0x575/0x810 net/core/net_namespace.c:702
 process_one_work+0x93a/0x12b0 kernel/workqueue.c:3326
 process_scheduled_works kernel/workqueue.c:3409 [inline]
 worker_thread+0xb05/0x10d0 kernel/workqueue.c:3490
 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 ffff88802b94ec00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 128 bytes inside of
 freed 192-byte region [ffff88802b94ec00, ffff88802b94ecc0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802b94e900 pfn:0x2b94e
flags: 0x80000000000200(workingset|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000200 ffff88813fe1f3c0 ffffea0000afd550 ffffea0000ce4390
raw: ffff88802b94e900 000000080010000e 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2c00(GFP_NOIO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1029, tgid 1029 (kworker/u8:8), ts 9427920788, free_ts 0
 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+0x2639/0x26b0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab+0x79/0x5e0 mm/slub.c:3406
 new_slab mm/slub.c:3452 [inline]
 refill_objects+0x2d8/0x350 mm/slub.c:7336
 refill_sheaf mm/slub.c:2830 [inline]
 __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4701
 alloc_from_pcs mm/slub.c:4799 [inline]
 slab_alloc_node mm/slub.c:4931 [inline]
 __do_kmalloc_node mm/slub.c:5359 [inline]
 __kmalloc_noprof+0x544/0x780 mm/slub.c:5385
 _kmalloc_noprof include/linux/slab.h:973 [inline]
 usb_alloc_urb+0x46/0x150 drivers/usb/core/urb.c:75
 usb_internal_control_msg drivers/usb/core/message.c:110 [inline]
 usb_control_msg+0x118/0x3e0 drivers/usb/core/message.c:167
 set_port_feature drivers/usb/core/hub.c:466 [inline]
 hub_suspend+0x891/0xad0 drivers/usb/core/hub.c:3996
 usb_suspend_interface drivers/usb/core/driver.c:1323 [inline]
 usb_suspend_both+0x285/0x1040 drivers/usb/core/driver.c:1446
 usb_runtime_suspend+0x58/0x110 drivers/usb/core/driver.c:2000
 __rpm_callback+0x2d6/0x930 drivers/base/power/runtime.c:406
 rpm_callback drivers/base/power/runtime.c:460 [inline]
 rpm_suspend+0x8a0/0x17a0 drivers/base/power/runtime.c:698
 __pm_runtime_suspend+0x12c/0x1a0 drivers/base/power/runtime.c:1167
 pm_runtime_autosuspend include/linux/pm_runtime.h:415 [inline]
 usb_runtime_idle+0x76/0x90 drivers/usb/core/driver.c:2037
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802b94eb80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
 ffff88802b94ec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802b94ec80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff88802b94ed00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88802b94ed80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
==================================================================