KCSAN: data-race in copy_page_to_iter / fat_alloc_new

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in copy_page_to_iter / fat_alloc_new_dir (2) exfat				1	944d	944d	0/26	auto-closed as invalid on 2021/10/22 18:51

================================================================== BUG: KCSAN: data-race in copy_page_to_iter / fat_alloc_new_dir write to 0xffff888130f82e2b of 1 bytes by task 10969 on cpu 1: fat_alloc_new_dir+0x1ab/0x4b0 fs/fat/dir.c:1163 vfat_mkdir+0x70/0x210 fs/fat/namei_vfat.c:860 vfs_mkdir+0x288/0x350 fs/namei.c:3650 do_mkdirat+0x132/0x220 fs/namei.c:3673 __do_sys_mkdirat fs/namei.c:3684 [inline] __se_sys_mkdirat fs/namei.c:3682 [inline] __x64_sys_mkdirat+0x3e/0x50 fs/namei.c:3682 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff888130f82000 of 4096 bytes by task 10973 on cpu 0: instrument_copy_to_user include/linux/instrumented.h:119 [inline] copyout lib/iov_iter.c:147 [inline] copy_page_to_iter_iovec lib/iov_iter.c:219 [inline] copy_page_to_iter+0x334/0x850 lib/iov_iter.c:926 generic_file_buffered_read+0x14d0/0x2110 mm/filemap.c:2332 generic_file_read_iter+0x80/0x3d0 mm/filemap.c:2535 blkdev_read_iter+0xb3/0xc0 fs/block_dev.c:1925 call_read_iter include/linux/fs.h:1897 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x552/0x5c0 fs/read_write.c:496 ksys_read+0xce/0x180 fs/read_write.c:634 __do_sys_read fs/read_write.c:644 [inline] __se_sys_read fs/read_write.c:642 [inline] __x64_sys_read+0x3e/0x50 fs/read_write.c:642 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 10973 Comm: systemd-udevd Not tainted 5.10.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================