================================================================== BUG: KCSAN: data-race in generic_write_end / mpage_process_page_bufs write to 0xffff888117660bc8 of 8 bytes by task 10914 on cpu 1: i_size_write include/linux/fs.h:913 [inline] generic_write_end+0x96/0x180 fs/buffer.c:2186 ext4_da_write_end+0x4de/0x630 fs/ext4/inode.c:3059 generic_perform_write+0x261/0x400 mm/filemap.c:3767 ext4_buffered_write_iter+0x25b/0x380 fs/ext4/file.c:269 ext4_file_write_iter+0x2e7/0x1200 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0x7f5/0x950 fs/read_write.c:590 ksys_write+0xd9/0x190 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:652 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 0xffff888117660bc8 of 8 bytes by task 10915 on cpu 0: i_size_read include/linux/fs.h:891 [inline] mpage_process_page_bufs+0x34/0x560 fs/ext4/inode.c:2187 mpage_prepare_extent_to_map+0x4f6/0x650 fs/ext4/inode.c:2621 ext4_writepages+0xa78/0x1e80 fs/ext4/inode.c:2793 do_writepages+0x1cb/0x330 mm/page-writeback.c:2364 filemap_fdatawrite_wbc mm/filemap.c:407 [inline] __filemap_fdatawrite_range mm/filemap.c:440 [inline] filemap_write_and_wait_range+0x1b2/0x340 mm/filemap.c:718 filemap_write_and_wait include/linux/fs.h:2865 [inline] fiemap_prep+0x149/0x160 fs/ioctl.c:194 iomap_fiemap+0x7f/0x410 fs/iomap/fiemap.c:75 ext4_fiemap+0x1ee/0x210 ioctl_fiemap fs/ioctl.c:219 [inline] do_vfs_ioctl+0xe57/0x14a0 fs/ioctl.c:814 __do_sys_ioctl fs/ioctl.c:872 [inline] __se_sys_ioctl+0x83/0x140 fs/ioctl.c:860 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860 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 value changed: 0x0000000000939000 -> 0x000000000093c000 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 10915 Comm: syz-executor.2 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================