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BUG: KASAN: use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff8881126a102a by task syz-executor/5846

CPU: 1 UID: 0 PID: 5846 Comm: syz-executor 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:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 4b e3 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000353f270 EFLAGS: 00000206
RAX: 203c6a8042bb5100 RBX: 0000000000000000 RCX: 203c6a8042bb5100
RDX: 0000000000000000 RSI: ffffffff8dba6163 RDI: ffffffff8be33300
RBP: ffffffff822e5a2a R08: 0000000000000000 R09: ffffffff822e5a2a
R10: dffffc0000000000 R11: fffff9400011d159 R12: 0000000000000002
R13: ffffffff8e139f60 R14: 0000000000000000 R15: 0000000000000246
 pfn_valid+0xd6/0x490
 page_table_check_set+0x25/0x730
 copy_pmd_range+0x4439/0x71d0
 copy_page_range+0xc14/0x1270
 dup_mmap+0xf57/0x1ac0
 copy_mm+0x13c/0x4b0
 copy_process+0x1706/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcff2385453
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc275adb48 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcff2385453
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555914bb7d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 0000000000047123 R15: 00007ffc275adce0
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffff00000000 pfn:0x1126a1
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000000 ffffea000449a888 ffffea00047ffb08 0000000000000000
raw: ffffffff00000000 ffff8881104a82a0 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 0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_COMP), pid 20814, tgid 20814 (syz.1.6439), ts 284334789168, free_ts 284380400696
 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
 __pmd_alloc+0x3a/0x3b0
 __handle_mm_fault+0x9ad/0x5440
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0xa81/0x1390
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
page last free pid 15 tgid 15 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __tlb_remove_table+0x2d2/0x3b0
 tlb_remove_table_rcu+0x85/0x100
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 run_ksoftirqd+0x9b/0x100
 smpboot_thread_fn+0x542/0xa60
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff8881126a0f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881126a0f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881126a1000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                  ^
 ffff8881126a1080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881126a1100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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