================================================================== BUG: KCSAN: data-race in _copy_to_iter / fat_set_state write to 0xffff88812212b025 of 1 bytes by task 3317 on cpu 0: fat_set_state+0x16c/0x1e0 fs/fat/inode.c:-1 fat_put_super+0x2e/0x80 fs/fat/inode.c:738 generic_shutdown_super+0xe6/0x210 fs/super.c:643 kill_block_super+0x2a/0x70 fs/super.c:1722 deactivate_locked_super+0x75/0x1c0 fs/super.c:474 deactivate_super+0x97/0xa0 fs/super.c:507 cleanup_mnt+0x2a9/0x320 fs/namespace.c:1318 __cleanup_mnt+0x19/0x20 fs/namespace.c:1325 task_work_run+0x131/0x1a0 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0x1fe/0x740 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x202/0x2a0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff88812212b000 of 1536 bytes by task 4034 on cpu 1: instrument_copy_to_user include/linux/instrumented.h:113 [inline] copy_to_user_iter lib/iov_iter.c:24 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] _copy_to_iter+0x130/0xe70 lib/iov_iter.c:197 copy_page_to_iter+0x18f/0x2d0 lib/iov_iter.c:374 copy_folio_to_iter include/linux/uio.h:204 [inline] filemap_read+0x407/0xa00 mm/filemap.c:2851 blkdev_read_iter+0x22d/0x2e0 block/fops.c:856 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x64c/0x770 fs/read_write.c:572 ksys_read+0xda/0x1a0 fs/read_write.c:715 __do_sys_read fs/read_write.c:724 [inline] __se_sys_read fs/read_write.c:722 [inline] __x64_sys_read+0x40/0x50 fs/read_write.c:722 x64_sys_call+0x2889/0x3000 arch/x86/include/generated/asm/syscalls_64.h:1 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd8/0x2a0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 4034 Comm: udevd Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 ==================================================================