================================================================== BUG: KCSAN: data-race in copy_page_to_iter / fat12_ent_put write to 0xffff888118d9e2b7 of 1 bytes by task 11855 on cpu 1: fat12_ent_put+0x76/0x180 fs/fat/fatent.c:167 fat_alloc_clusters+0x47d/0xa80 fs/fat/fatent.c:502 fat_add_cluster fs/fat/inode.c:108 [inline] __fat_get_block fs/fat/inode.c:155 [inline] fat_get_block+0x263/0x600 fs/fat/inode.c:190 __block_write_begin_int+0x33d/0xc90 fs/buffer.c:2006 __block_write_begin fs/buffer.c:2056 [inline] block_write_begin+0x77/0x170 fs/buffer.c:2117 cont_write_begin+0x3cf/0x500 fs/buffer.c:2463 fat_write_begin+0x61/0xf0 fs/fat/inode.c:235 generic_perform_write+0x1d6/0x3f0 mm/filemap.c:3793 __generic_file_write_iter+0x172/0x280 mm/filemap.c:3889 generic_file_write_iter+0x75/0x130 mm/filemap.c:3953 do_iter_readv_writev+0x27b/0x300 do_iter_write+0x16f/0x5c0 fs/read_write.c:852 vfs_iter_write+0x4c/0x70 fs/read_write.c:893 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x660 fs/splice.c:891 do_splice_direct+0xfb/0x180 fs/splice.c:979 do_sendfile+0x3ad/0x900 fs/read_write.c:1246 __do_sys_sendfile64 fs/read_write.c:1311 [inline] __se_sys_sendfile64 fs/read_write.c:1297 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff888118d9e000 of 1377 bytes by task 1905 on cpu 0: instrument_copy_to_user include/linux/instrumented.h:119 [inline] copyout lib/iov_iter.c:154 [inline] copy_page_to_iter_iovec lib/iov_iter.c:226 [inline] __copy_page_to_iter lib/iov_iter.c:852 [inline] copy_page_to_iter+0x415/0x7b0 lib/iov_iter.c:880 copy_folio_to_iter include/linux/uio.h:153 [inline] filemap_read+0x10b2/0x1400 mm/filemap.c:2736 blkdev_read_iter+0x2c6/0x370 block/fops.c:611 call_read_iter include/linux/fs.h:2044 [inline] new_sync_read fs/read_write.c:401 [inline] vfs_read+0x5a5/0x6a0 fs/read_write.c:482 ksys_read+0xe8/0x1a0 fs/read_write.c:620 __do_sys_read fs/read_write.c:630 [inline] __se_sys_read fs/read_write.c:628 [inline] __x64_sys_read+0x3e/0x50 fs/read_write.c:628 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 1905 Comm: udevd Tainted: G W 5.18.0-rc2-syzkaller-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================