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BUG: KASAN: use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff888022d0182a by task syz.0.6241/29602

CPU: 1 UID: 0 PID: 29602 Comm: syz.0.6241 Not tainted 6.16.0-rc6-syzkaller-01577-gdd500e4aecf2 #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+0xca/0x230
 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:unwind_next_frame+0x1312/0x2390
Code: 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 <49> 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49 8d 47 fc 48
RSP: 0018:ffffc9000a196f78 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8fc21bf8 RCX: dffffc0000000000
RDX: ffffffff8fc21bd8 RSI: ffffffff9043fe1a RDI: ffffffff8be28be0
RBP: ffffffff8fc21bec R08: 0000000000000009 R09: ffffffff8172aae5
R10: ffffc9000a197098 R11: ffffffff81ad0050 R12: ffffffff825d31c8
R13: ffffffff8fc21be8 R14: ffffc9000a197048 R15: ffffffff8fc21bf0
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 __kernfs_new_node+0xd7/0x7e0
 kernfs_new_node+0x102/0x210
 __kernfs_create_file+0x4b/0x2e0
 sysfs_add_file_mode_ns+0x238/0x300
 internal_create_group+0x66d/0x1110
 sysfs_create_groups+0x59/0x120
 device_add_attrs+0xe0/0x5a0
 device_add+0x496/0xb50
 netdev_register_kobject+0x178/0x310
 register_netdevice+0x126c/0x1ae0
 register_netdev+0x40/0x60
 loopback_net_init+0x75/0x150
 ops_init+0x35c/0x5c0
 setup_net+0x10c/0x320
 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
RIP: 0033:0x7f865bb8e9a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f865cabe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f865bdb5fa0 RCX: 00007f865bb8e9a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000
RBP: 00007f865bc10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f865bdb5fa0 R15: 00007ffd2952ecd8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x22d01
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00008b4008 ffffea00008b4088 0000000000000000
raw: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO|__GFP_NOWARN), pid 29452, tgid 29443 (syz.2.6201), ts 421981331455, free_ts 422142546135
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 alloc_pages_noprof+0xa9/0x190
 __vmalloc_node_range_noprof+0x97d/0x12f0
 vmalloc_user_noprof+0xad/0xf0
 xskq_create+0xbf/0x170
 xsk_init_queue+0xb0/0x110
 xsk_setsockopt+0x57b/0x8d0
 do_sock_setsockopt+0x17c/0x1b0
 __x64_sys_setsockopt+0x13f/0x1b0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 29443 tgid 29443 stack trace:
 __free_frozen_pages+0xc71/0xe70
 vfree+0x25a/0x400
 xskq_destroy+0x40/0x60
 xsk_release+0x64b/0x890
 sock_close+0xc3/0x240
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888022d01700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888022d01780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888022d01800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                  ^
 ffff888022d01880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888022d01900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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