syzbot

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BUG: KCSAN: data-race in _copy_to_iter / fat_set_state

write to 0xffff888151686025 of 1 bytes by task 5347 on cpu 0:
 fat_set_state+0x16e/0x1d0
 fat_fill_super+0x2479/0x28e0 fs/fat/inode.c:1877
 vfat_fill_super+0x30/0x40 fs/fat/namei_vfat.c:1200
 mount_bdev+0x1f3/0x290 fs/super.c:1380
 vfat_mount+0x31/0x40 fs/fat/namei_vfat.c:1207
 legacy_get_tree+0x74/0xd0 fs/fs_context.c:610
 vfs_get_tree+0x51/0x190 fs/super.c:1510
 do_new_mount+0x203/0x660 fs/namespace.c:3039
 path_mount+0x498/0xb40 fs/namespace.c:3369
 do_mount fs/namespace.c:3382 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3568
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888151686000 of 1377 bytes by task 29018 on cpu 1:
 instrument_copy_to_user include/linux/instrumented.h:113 [inline]
 copyout lib/iov_iter.c:169 [inline]
 _copy_to_iter+0x142/0x940 lib/iov_iter.c:536
 copy_page_to_iter+0x1a8/0x310 lib/iov_iter.c:742
 copy_folio_to_iter include/linux/uio.h:197 [inline]
 filemap_read+0x438/0x680 mm/filemap.c:2748
 blkdev_read_iter+0x2ca/0x370 block/fops.c:606
 call_read_iter include/linux/fs.h:1862 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x3b7/0x580 fs/read_write.c:470
 ksys_read+0xeb/0x1a0 fs/read_write.c:613
 __do_sys_read fs/read_write.c:623 [inline]
 __se_sys_read fs/read_write.c:621 [inline]
 __x64_sys_read+0x42/0x50 fs/read_write.c:621
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29018 Comm: udevd Not tainted 6.4.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
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I/O error, dev loop3, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop3, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2