FAT-fs (loop4): bogus number of FAT sectors
FAT-fs (loop4): Can't find a valid FAT filesystem
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BUG: KCSAN: data-race in lru_add_drain_all / lru_cache_add

write to 0xffff88812c128ac0 of 1 bytes by task 15313 on cpu 1:
 pagevec_add include/linux/pagevec.h:81 [inline]
 lru_cache_add+0x92/0x170 mm/swap.c:473
 lru_cache_add_active_or_unevictable+0x6d/0x110 mm/swap.c:506
 wp_page_copy+0x869/0x1620 mm/memory.c:2714
 do_wp_page+0x9c3/0xd40 mm/memory.c:2981
 handle_pte_fault mm/memory.c:4232 [inline]
 __handle_mm_fault mm/memory.c:4346 [inline]
 handle_mm_fault+0x1658/0x18a0 mm/memory.c:4383
 do_user_addr_fault+0x393/0x810 arch/x86/mm/fault.c:1295
 handle_page_fault arch/x86/mm/fault.c:1365 [inline]
 exc_page_fault+0xb8/0x330 arch/x86/mm/fault.c:1418
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:565

read to 0xffff88812c128ac0 of 1 bytes by task 15309 on cpu 0:
 pagevec_count include/linux/pagevec.h:68 [inline]
 lru_add_drain_all+0x114/0x390 mm/swap.c:795
 invalidate_bdev+0x50/0x70 fs/block_dev.c:97
 __loop_clr_fd+0x258/0x5b0 drivers/block/loop.c:1243
 loop_clr_fd drivers/block/loop.c:1340 [inline]
 lo_ioctl+0x9d1/0x1190 drivers/block/loop.c:1698
 __blkdev_driver_ioctl block/ioctl.c:224 [inline]
 blkdev_ioctl+0x1b2/0x3f0 block/ioctl.c:620
 block_ioctl+0x6d/0x80 fs/block_dev.c:1987
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl fs/ioctl.c:753 [inline]
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl+0xc9/0x130 fs/ioctl.c:760
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:760
 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15309 Comm: syz-executor.4 Not tainted 5.8.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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