==================================================================
BUG: KASAN: use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff8881108f4c2a by task syz.0.7230/32532

CPU: 0 UID: 0 PID: 32532 Comm: syz.0.7230 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
 do_softirq+0xec/0x180
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0
 raw6_destroy+0x17/0x30
 sk_common_release+0x75/0x2e0
 inet_release+0x144/0x190
 sock_close+0xc3/0x240
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9b0eb8ebe9
Code: Unable to access opcode bytes at 0x7f9b0eb8ebbf.
RSP: 002b:00007f9b0f9d6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffed RBX: 00007f9b0edb5fa0 RCX: 00007f9b0eb8ebe9
RDX: 0000200000000040 RSI: 0000000000008b23 RDI: 0000000000000086
RBP: 00007f9b0ec11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9b0edb6038 R14: 00007f9b0edb5fa0 R15: 00007ffedd596438
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8881108f7800 pfn:0x1108f4
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: ffff8881108f7800 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 26631, tgid 26631 (dhcpcd-run-hook), ts 448997514435, free_ts 458036062675
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x8a/0x370
 ___slab_alloc+0xbeb/0x1410
 __kmalloc_noprof+0x305/0x4f0
 tomoyo_realpath_from_path+0xe3/0x5d0
 tomoyo_path_perm+0x213/0x4b0
 security_inode_getattr+0x12f/0x330
 vfs_fstatat+0xb1/0x170
 __x64_sys_newfstatat+0x116/0x190
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 27209 tgid 27209 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __put_partials+0x156/0x1a0
 put_cpu_partial+0x17c/0x250
 __slab_free+0x2d5/0x3c0
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 jbd2__journal_start+0x146/0x5b0
 __ext4_journal_start_sb+0x227/0x5c0
 ext4_dirty_inode+0x93/0x110
 __mark_inode_dirty+0x2ec/0xe10
 touch_atime+0x59b/0x6d0
 ext4_file_mmap_prepare+0x24d/0x440
 mmap_region+0xb41/0x20c0
 do_mmap+0xc45/0x10d0

Memory state around the buggy address:
 ffff8881108f4b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881108f4b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881108f4c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                  ^
 ffff8881108f4c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881108f4d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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