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BUG: KASAN: use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff888029129c2a by task syz.2.4152/20786

CPU: 0 UID: 0 PID: 20786 Comm: syz.2.4152 Not tainted syzkaller #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/0x240
 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:__tlb_remove_folio_pages_size+0x149/0x5a0
Code: 08 4d 8d 6c 24 0c 4c 89 e8 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 0d 03 00 00 45 8b 6d 00 41 ff cd 89 ef 44 89 ee e8 17 84 b1 ff <44> 39 ed 73 0a e8 4d 82 b1 ff e9 96 00 00 00 4d 8d 67 20 4c 89 e0
RSP: 0018:ffffc90006287588 EFLAGS: 00000293
RAX: ffffffff820e28d9 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff8880210d1cc0 RSI: 00000000000001fd RDI: 00000000000000d9
RBP: 00000000000000d9 R08: ffffea00042cb333 R09: 1ffffd4000859666
R10: dffffc0000000000 R11: fffff94000859667 R12: ffff888021389000
R13: 00000000000001fd R14: 1ffff92000c50f59 R15: ffffc90006287aa0
 unmap_page_range+0x20ac/0x4370
 unmap_vmas+0x399/0x580
 exit_mmap+0x248/0xb50
 __mmput+0x118/0x420
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa9f298ebe9
Code: Unable to access opcode bytes at 0x7fa9f298ebbf.
RSP: 002b:00007ffea51b6b98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa9f298ebe9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffea51b6bfc R08: 00000016a51b6c8f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000571
R13: 00000000000927c0 R14: 0000000000040c7e R15: 00007ffea51b6c50
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x29129
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 00000000ffffffff 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 2, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_ZERO|__GFP_COMP), pid 20513, tgid 20511 (syz.0.4068), ts 262934894066, free_ts 263266843289
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 ___kmalloc_large_node+0x5f/0x1b0
 __kmalloc_large_node_noprof+0x18/0x90
 __kmalloc_noprof+0x36f/0x4f0
 ops_init+0x7b/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
page last free pid 5895 tgid 5895 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 free_large_kmalloc+0x13a/0x1f0
 ops_undo_list+0x856/0x990
 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

Memory state around the buggy address:
 ffff888029129b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888029129b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888029129c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                  ^
 ffff888029129c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888029129d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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