================================================================== BUG: KCSAN: data-race in copy_page_to_iter / fat16_ent_put write to 0xffff88814b326316 of 2 bytes by task 31566 on cpu 0: fat16_ent_put+0x24/0x50 fs/fat/fatent.c:182 fat_free_clusters+0x2aa/0x870 fs/fat/fatent.c:596 fat_free fs/fat/file.c:375 [inline] fat_truncate_blocks+0x52e/0x580 fs/fat/file.c:393 fat_setattr+0x6ae/0x7d0 fs/fat/file.c:539 notify_change+0x8a3/0xac0 fs/attr.c:410 do_truncate+0xf7/0x140 fs/open.c:64 handle_truncate fs/namei.c:3082 [inline] do_open fs/namei.c:3430 [inline] path_openat+0x191f/0x1eb0 fs/namei.c:3559 do_filp_open+0x105/0x220 fs/namei.c:3586 do_sys_openat2+0xb5/0x2b0 fs/open.c:1212 do_sys_open fs/open.c:1228 [inline] __do_sys_creat fs/open.c:1304 [inline] __se_sys_creat fs/open.c:1298 [inline] __x64_sys_creat+0x62/0x80 fs/open.c:1298 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88814b326000 of 1024 bytes by task 2299 on cpu 1: instrument_copy_to_user include/linux/instrumented.h:119 [inline] copyout lib/iov_iter.c:156 [inline] copy_page_to_iter_iovec lib/iov_iter.c:228 [inline] __copy_page_to_iter lib/iov_iter.c:852 [inline] copy_page_to_iter+0x2cb/0x950 lib/iov_iter.c:880 filemap_read+0x138b/0x16d0 mm/filemap.c:2697 generic_file_read_iter+0x72/0x2a0 mm/filemap.c:2792 blkdev_read_iter+0x96/0x140 block/fops.c:583 call_read_iter include/linux/fs.h:2156 [inline] new_sync_read fs/read_write.c:400 [inline] vfs_read+0x66c/0x750 fs/read_write.c:481 ksys_read+0xd9/0x190 fs/read_write.c:619 __do_sys_read fs/read_write.c:629 [inline] __se_sys_read fs/read_write.c:627 [inline] __x64_sys_read+0x3e/0x50 fs/read_write.c:627 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 2299 Comm: udevd Tainted: G W 5.16.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================