================================================================== BUG: KCSAN: data-race in mark_buffer_dirty_inode / mark_buffer_dirty_inode write to 0xffff8880b7d04190 of 8 bytes by task 15011 on cpu 1: mark_buffer_dirty_inode+0x185/0x1b0 fs/buffer.c:586 fat_mirror_bhs+0x200/0x320 fs/fat/fatent.c:396 fat_alloc_clusters+0x95e/0xa60 fs/fat/fatent.c:541 fat_add_cluster fs/fat/inode.c:108 [inline] __fat_get_block fs/fat/inode.c:155 [inline] fat_get_block+0x213/0x5a0 fs/fat/inode.c:190 __block_write_begin_int+0x4bf/0xfd0 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin+0x4f/0x190 fs/buffer.c:2121 cont_write_begin+0x42c/0x610 fs/buffer.c:2470 fat_write_begin+0x61/0xf0 fs/fat/inode.c:235 generic_perform_write+0x196/0x390 mm/filemap.c:3299 __generic_file_write_iter+0x225/0x330 mm/filemap.c:3396 generic_file_write_iter+0x2f3/0x3e0 mm/filemap.c:3460 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write fs/read_write.c:484 [inline] __vfs_write+0x2d8/0x340 fs/read_write.c:497 vfs_write+0x19b/0x350 fs/read_write.c:559 ksys_write+0xce/0x180 fs/read_write.c:612 __do_sys_write fs/read_write.c:624 [inline] __se_sys_write fs/read_write.c:621 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:621 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8880b7d04190 of 8 bytes by task 15000 on cpu 0: mark_buffer_dirty_inode+0x92/0x1b0 fs/buffer.c:582 fat_mirror_bhs+0x200/0x320 fs/fat/fatent.c:396 fat_alloc_clusters+0x95e/0xa60 fs/fat/fatent.c:541 fat_add_cluster fs/fat/inode.c:108 [inline] __fat_get_block fs/fat/inode.c:155 [inline] fat_get_block+0x213/0x5a0 fs/fat/inode.c:190 __block_write_begin_int+0x4bf/0xfd0 fs/buffer.c:2012 __block_write_begin fs/buffer.c:2062 [inline] block_write_begin+0x4f/0x190 fs/buffer.c:2121 cont_write_begin+0x42c/0x610 fs/buffer.c:2470 fat_write_begin+0x61/0xf0 fs/fat/inode.c:235 generic_perform_write+0x196/0x390 mm/filemap.c:3299 __generic_file_write_iter+0x154/0x330 mm/filemap.c:3428 generic_file_write_iter+0x2f3/0x3e0 mm/filemap.c:3460 call_write_iter include/linux/fs.h:1907 [inline] do_iter_readv_writev+0x321/0x3c0 fs/read_write.c:694 do_iter_write+0x10e/0x470 fs/read_write.c:999 vfs_iter_write+0x4c/0x70 fs/read_write.c:1040 iter_file_splice_write+0x41a/0x770 fs/splice.c:750 do_splice_from fs/splice.c:846 [inline] direct_splice_actor+0x95/0x160 fs/splice.c:1016 splice_direct_to_actor+0x365/0x660 fs/splice.c:971 do_splice_direct+0xf2/0x170 fs/splice.c:1059 do_sendfile+0x562/0xb10 fs/read_write.c:1521 __do_sys_sendfile64 fs/read_write.c:1576 [inline] __se_sys_sendfile64 fs/read_write.c:1568 [inline] __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1568 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 15000 Comm: syz-executor.2 Not tainted 5.8.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================