================================================================== BUG: KCSAN: data-race in __filemap_add_folio / filemap_write_and_wait_range read-write to 0xffff888100481e78 of 8 bytes by task 10240 on cpu 0: __filemap_add_folio+0x5b9/0x7d0 mm/filemap.c:928 filemap_add_folio+0x98/0x1b0 mm/filemap.c:969 page_cache_ra_unbounded+0x1f3/0x380 mm/readahead.c:275 do_page_cache_ra mm/readahead.c:327 [inline] force_page_cache_ra mm/readahead.c:356 [inline] page_cache_sync_ra+0x256/0x6c0 mm/readahead.c:572 filemap_get_pages+0x2d0/0x1150 mm/filemap.c:2603 filemap_read+0x231/0xa00 mm/filemap.c:2712 blkdev_read_iter+0x22d/0x2e0 block/fops.c:849 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x649/0x770 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+0x27bc/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:1 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff888100481e78 of 8 bytes by task 3307 on cpu 1: mapping_needs_writeback mm/filemap.c:641 [inline] filemap_write_and_wait_range+0x59/0x340 mm/filemap.c:690 filemap_write_and_wait include/linux/pagemap.h:68 [inline] sync_blockdev+0x35/0x50 block/bdev.c:260 sync_filesystem+0x162/0x190 fs/sync.c:70 generic_shutdown_super+0x44/0x210 fs/super.c:622 kill_block_super+0x2a/0x70 fs/super.c:1766 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7395 deactivate_locked_super+0x72/0x1c0 fs/super.c:474 deactivate_super+0x97/0xa0 fs/super.c:507 cleanup_mnt+0x269/0x2e0 fs/namespace.c:1378 __cleanup_mnt+0x19/0x20 fs/namespace.c:1385 task_work_run+0x12e/0x1a0 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xe4/0x100 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x0000000000000007 -> 0x0000000000000008 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 3307 Comm: syz-executor Not tainted 6.17.0-rc2-syzkaller-00028-gbe48bcf004f9 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 ================================================================== EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000.