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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88810968902a by task swapper/0/0

CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc5-syzkaller-00212-g9f735b6f8a77 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250
 print_report+0xd2/0x2b0
 kasan_report+0x118/0x150
 rose_timer_expiry+0x471/0x4b0
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:pv_native_safe_halt+0x13/0x20
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 93 dd 1a 00 f3 0f 1e fa fb f4 <e9> c8 dd 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 00000286
RAX: 4b62917386238700 RBX: ffffffff81976c78 RCX: 4b62917386238700
RDX: 0000000000000001 RSI: ffffffff8d996033 RDI: ffffffff8be28c40
RBP: ffffffff8de07ea8 R08: ffff88804b032f5b R09: 1ffff110096065eb
R10: dffffc0000000000 R11: ffffed10096065ec R12: ffffffff8fa1d5f0
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50
 default_idle+0x13/0x20
 default_idle_call+0x74/0xb0
 do_idle+0x1e8/0x510
 cpu_startup_entry+0x44/0x60
 rest_init+0x2de/0x300
 start_kernel+0x47d/0x500
 x86_64_start_reservations+0x24/0x30
 x86_64_start_kernel+0x143/0x1c0
 common_startup_64+0x13e/0x147
 </TASK>

Allocated by task 19810:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 device_add+0xbe/0xb50
 netdev_register_kobject+0x156/0x2f0
 register_netdevice+0x126c/0x1ae0
 register_netdev+0x40/0x60
 sit_init_net+0x228/0x5c0
 ops_init+0x35c/0x5c0
 setup_net+0x219/0x4b0
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 13:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kfree+0x18e/0x440
 kobject_put+0x22b/0x480
 netdev_run_todo+0xd2e/0xea0
 ops_undo_list+0x3e1/0x990
 cleanup_net+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff888109689000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff888109689000, ffff888109689200)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88810968a000 pfn:0x109688
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000240(workingset|head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000240 ffff88801a441c80 ffffea0004b3bb10 ffffea00048eab10
raw: ffff88810968a000 0000000000100004 00000000f5000000 0000000000000000
head: 057ff00000000240 ffff88801a441c80 ffffea0004b3bb10 ffffea00048eab10
head: ffff88810968a000 0000000000100004 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea000425a201 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 5279, tgid 5279 (udevd), ts 49433058251, free_ts 49425755224
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 allocate_slab+0x65/0x3b0
 ___slab_alloc+0xbfc/0x1480
 __kmalloc_node_noprof+0x2fd/0x4e0
 allocate_slab+0x17c/0x3b0
 ___slab_alloc+0xbfc/0x1480
 kmem_cache_alloc_noprof+0x283/0x3c0
 __send_signal_locked+0x22a/0xeb0
 group_send_sig_info+0x1fd/0x260
 do_bpf_send_signal+0xa9/0x1e0
 irq_work_single+0xe1/0x240
 irq_work_run+0x155/0x2f0
 __sysvec_irq_work+0xa8/0x3d0
 sysvec_irq_work+0x9e/0xc0
page last free pid 5279 tgid 5279 stack trace:
 __free_frozen_pages+0xc71/0xe70
 __put_partials+0x161/0x1c0
 put_cpu_partial+0x17c/0x250
 __slab_free+0x2f7/0x400
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 getname_flags+0xb8/0x540
 __x64_sys_unlink+0x3a/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888109688f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888109688f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888109689000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888109689080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888109689100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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