================================================================== BUG: KCSAN: data-race in copy_page_to_iter / fat12_ent_put write to 0xffff88811378f212 of 1 bytes by task 10452 on cpu 0: fat12_ent_put+0x76/0x180 fs/fat/fatent.c:167 fat_ent_write+0x5e/0xd0 fs/fat/fatent.c:416 fat_chain_add+0x15b/0x410 fs/fat/misc.c:130 fat_add_cluster fs/fat/inode.c:113 [inline] __fat_get_block fs/fat/inode.c:155 [inline] fat_get_block+0x48d/0x610 fs/fat/inode.c:190 __block_write_begin_int+0x345/0xc70 fs/buffer.c:2006 __block_write_begin fs/buffer.c:2056 [inline] block_write_begin+0x83/0x270 fs/buffer.c:2117 cont_write_begin+0x3bf/0x4f0 fs/buffer.c:2464 fat_write_begin+0x61/0xf0 fs/fat/inode.c:235 generic_perform_write+0x1c8/0x3f0 mm/filemap.c:3792 __generic_file_write_iter+0xf7/0x2b0 mm/filemap.c:3919 generic_file_write_iter+0x75/0x130 mm/filemap.c:3951 call_write_iter include/linux/fs.h:2079 [inline] do_iter_readv_writev+0x27d/0x320 fs/read_write.c:726 do_iter_write+0x192/0x5c0 fs/read_write.c:852 vfs_iter_write+0x4c/0x70 fs/read_write.c:893 iter_file_splice_write+0x43a/0x790 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+0x345/0x650 fs/splice.c:891 do_splice_direct+0x106/0x190 fs/splice.c:979 do_sendfile+0x675/0xc40 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+0x102/0x140 fs/read_write.c:1297 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88811378f000 of 1377 bytes by task 10454 on cpu 1: 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+0x427/0x7c0 lib/iov_iter.c:880 copy_folio_to_iter include/linux/uio.h:153 [inline] filemap_read+0xb2f/0xe10 mm/filemap.c:2736 blkdev_read_iter+0x2cc/0x380 block/fops.c:611 call_read_iter include/linux/fs.h:2073 [inline] new_sync_read fs/read_write.c:401 [inline] vfs_read+0x5e2/0x6c0 fs/read_write.c:482 ksys_read+0xd9/0x190 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/0x50 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 10454 Comm: udevd Not tainted 5.17.0-syzkaller-13673-ge8b767f5e040-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================