syzbot

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BUG: KCSAN: data-race in ktime_get_real_seconds / timekeeping_advance

write to 0xffffffff8603db08 of 280 bytes by interrupt on cpu 0:
 timekeeping_advance+0x893/0xd80 include/linux/string.h:359
 update_wall_time+0x19/0x20 kernel/time/timekeeping.c:2137
 tick_do_update_jiffies64+0x1ae/0x260 kernel/time/tick-sched.c:94
 tick_sched_do_timer+0xd4/0xe0 kernel/time/tick-sched.c:138
 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1289
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x288/0x600 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 should_watch kernel/kcsan/core.c:188 [inline]
 __kcsan_setup_watchpoint+0xa8/0x510 kernel/kcsan/core.c:348
 __tsan_read4 kernel/kcsan/kcsan.c:30 [inline]
 __tsan_read4+0x2c/0x30 kernel/kcsan/kcsan.c:30
 arch_atomic_read arch/x86/include/asm/atomic.h:31 [inline]
 atomic_read include/asm-generic/atomic-instrumented.h:29 [inline]
 page_mapcount include/linux/mm.h:728 [inline]
 zap_pte_range mm/memory.c:1060 [inline]
 zap_pmd_range mm/memory.c:1161 [inline]
 zap_pud_range mm/memory.c:1190 [inline]
 zap_p4d_range mm/memory.c:1211 [inline]
 unmap_page_range+0x11c5/0x1720 mm/memory.c:1232
 unmap_single_vma+0x144/0x200 mm/memory.c:1277
 unmap_vmas+0xda/0x1a0 mm/memory.c:1309

read to 0xffffffff8603db78 of 8 bytes by task 10277 on cpu 1:
 ktime_get_real_seconds+0x20/0x40 kernel/time/timekeeping.c:127
 recently_deleted fs/ext4/ialloc.c:699 [inline]
 find_inode_bit.isra.0+0x1e2/0x300 fs/ext4/ialloc.c:722
 __ext4_new_inode+0xd4b/0x3070 fs/ext4/ialloc.c:914
 ext4_symlink+0x30e/0x970 fs/ext4/namei.c:3262
 vfs_symlink fs/namei.c:4127 [inline]
 vfs_symlink+0x218/0x310 fs/namei.c:4113
 do_symlinkat+0x1a5/0x1e0 fs/namei.c:4154
 __do_sys_symlink fs/namei.c:4173 [inline]
 __se_sys_symlink fs/namei.c:4171 [inline]
 __x64_sys_symlink+0x3f/0x50 fs/namei.c:4171
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10277 Comm: syz-executor.3 Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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