================================================================== BUG: KCSAN: data-race in generic_write_end / mpage_process_page_bufs write to 0xffff888109632168 of 8 bytes by task 3906 on cpu 1: i_size_write include/linux/fs.h:901 [inline] generic_write_end+0x9f/0x240 fs/buffer.c:2304 ext4_da_write_end+0x49e/0x700 fs/ext4/inode.c:2988 generic_perform_write+0x26d/0x410 mm/filemap.c:3934 ext4_buffered_write_iter+0x1f6/0x370 fs/ext4/file.c:299 ext4_file_write_iter+0x283/0x1230 call_write_iter include/linux/fs.h:1877 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4ab/0x7d0 fs/read_write.c:584 ksys_write+0xeb/0x1a0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x42/0x50 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff888109632168 of 8 bytes by task 3915 on cpu 0: i_size_read include/linux/fs.h:879 [inline] mpage_process_page_bufs+0x34/0x5e0 fs/ext4/inode.c:1956 mpage_prepare_extent_to_map+0x794/0xb90 fs/ext4/inode.c:2487 ext4_do_writepages+0xa5e/0x21e0 fs/ext4/inode.c:2675 ext4_writepages+0x15e/0x2e0 fs/ext4/inode.c:2766 do_writepages+0x1c5/0x340 mm/page-writeback.c:2553 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:393 __filemap_fdatawrite_range mm/filemap.c:426 [inline] __filemap_fdatawrite mm/filemap.c:432 [inline] filemap_flush+0x95/0xc0 mm/filemap.c:459 ext4_alloc_da_blocks+0x50/0x130 fs/ext4/inode.c:3033 ext4_release_file+0x5f/0x1c0 fs/ext4/file.c:169 __fput+0x2fd/0x600 fs/file_table.c:384 ____fput+0x15/0x20 fs/file_table.c:412 task_work_run+0x135/0x1a0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xd1/0xe0 kernel/entry/common.c:171 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x0000000000313000 -> 0x0000000000315000 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 3915 Comm: syz-executor.1 Not tainted 6.5.0-rc6-syzkaller-00117-g0e8860d2125f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 ================================================================== syz-executor.1 (3915) used greatest stack depth: 10904 bytes left