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BUG: KCSAN: data-race in ktime_get_real_seconds / timekeeping_advance

write to 0xffffffff88ae90c8 of 280 bytes by interrupt on cpu 0:
 timekeeping_advance+0x88e/0xd80 include/linux/string.h:381
 update_wall_time+0x15/0x20 kernel/time/timekeeping.c:2136
 tick_do_update_jiffies64+0x1e5/0x2a0 kernel/time/tick-sched.c:101
 tick_sched_do_timer+0xc7/0xd0 kernel/time/tick-sched.c:147
 tick_sched_timer+0x3f/0xd0 kernel/time/tick-sched.c:1313
 __run_hrtimer kernel/time/hrtimer.c:1520 [inline]
 __hrtimer_run_queues+0x271/0x600 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x226/0x490 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113 [inline]
 smp_apic_timer_interrupt+0xd8/0x270 arch/x86/kernel/apic/apic.c:1138
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 check_access kernel/kcsan/core.c:583 [inline]
 __tsan_unaligned_write4+0x9e/0x110 kernel/kcsan/core.c:769
 rcu_preempt_depth_set kernel/rcu/tree_plugin.h:365 [inline]
 __rcu_read_unlock+0xa1/0x390 kernel/rcu/tree_plugin.h:397
 rcu_read_unlock include/linux/rcupdate.h:654 [inline]
 get_mem_cgroup_from_mm mm/memcontrol.c:955 [inline]
 get_mem_cgroup_from_mm+0xa8/0x170 mm/memcontrol.c:933
 mem_cgroup_try_charge+0xc2/0x260 mm/memcontrol.c:6483
 mem_cgroup_try_charge_delay+0x36/0x70 mm/memcontrol.c:6500
 shmem_getpage_gfp+0x3f3/0x16c0 mm/shmem.c:1862
 shmem_fault+0x117/0x4b0 mm/shmem.c:2062
 __do_fault+0xa8/0x1e0 mm/memory.c:3450
 do_read_fault mm/memory.c:3846 [inline]
 do_fault mm/memory.c:3975 [inline]
 handle_pte_fault mm/memory.c:4215 [inline]
 __handle_mm_fault+0x295c/0x2da0 mm/memory.c:4345
 handle_mm_fault+0x21c/0x540 mm/memory.c:4382
 faultin_page mm/gup.c:879 [inline]
 __get_user_pages+0x533/0x11c0 mm/gup.c:1098
 populate_vma_page_range+0xdc/0x100 mm/gup.c:1430
 __mm_populate+0x168/0x2b0 mm/gup.c:1478
 mm_populate include/linux/mm.h:2562 [inline]
 vm_mmap_pgoff+0x185/0x190 mm/util.c:511
 ksys_mmap_pgoff+0x96/0x420 mm/mmap.c:1595
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffffff88ae9138 of 8 bytes by task 26096 on cpu 1:
 ktime_get_real_seconds+0x1d/0x30 kernel/time/timekeeping.c:127
 recently_deleted fs/ext4/ialloc.c:699 [inline]
 find_inode_bit.isra.0+0x1e7/0x330 fs/ext4/ialloc.c:724
 __ext4_new_inode+0xd7b/0x3020 fs/ext4/ialloc.c:927
 ext4_symlink+0x322/0x9e0 fs/ext4/namei.c:3295
 vfs_symlink fs/namei.c:3937 [inline]
 vfs_symlink+0x216/0x330 fs/namei.c:3923
 do_symlinkat+0x1ac/0x1e0 fs/namei.c:3964
 __do_sys_symlink fs/namei.c:3983 [inline]
 __se_sys_symlink fs/namei.c:3981 [inline]
 __x64_sys_symlink+0x3c/0x50 fs/namei.c:3981
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26096 Comm: syz-executor.0 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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