================================================================== BUG: KCSAN: data-race in generic_write_end / mpage_process_page_bufs write to 0xffff88811d8d3748 of 8 bytes by task 7480 on cpu 0: i_size_write include/linux/fs.h:878 [inline] generic_write_end+0x98/0x230 fs/buffer.c:2183 ext4_da_write_end+0x26c/0x620 fs/ext4/inode.c:3068 generic_perform_write+0x26a/0x3f0 mm/filemap.c:3798 ext4_buffered_write_iter+0x222/0x330 fs/ext4/file.c:270 ext4_file_write_iter+0x2e3/0x1210 call_write_iter include/linux/fs.h:2050 [inline] new_sync_write fs/read_write.c:504 [inline] vfs_write+0x71c/0x890 fs/read_write.c:591 ksys_write+0xe8/0x1a0 fs/read_write.c:644 __do_sys_write fs/read_write.c:656 [inline] __se_sys_write fs/read_write.c:653 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:653 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88811d8d3748 of 8 bytes by task 7498 on cpu 1: i_size_read include/linux/fs.h:856 [inline] mpage_process_page_bufs+0x34/0x530 fs/ext4/inode.c:2182 mpage_prepare_extent_to_map+0x5b7/0xa50 fs/ext4/inode.c:2630 ext4_writepages+0x9b8/0x1d00 fs/ext4/inode.c:2802 do_writepages+0x1db/0x350 mm/page-writeback.c:2352 filemap_fdatawrite_wbc+0xd6/0xf0 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] filemap_write_and_wait_range+0xbf/0x2e0 mm/filemap.c:673 ext4_punch_hole+0x171/0x890 fs/ext4/inode.c:3984 ext4_fallocate+0xea/0x420 fs/ext4/extents.c:4697 vfs_fallocate+0x355/0x3d0 fs/open.c:308 do_vfs_ioctl+0x12d9/0x1390 fs/ioctl.c:849 __do_sys_ioctl fs/ioctl.c:868 [inline] __se_sys_ioctl+0x83/0x140 fs/ioctl.c:856 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x000000000049d000 -> 0x000000000049e000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 7498 Comm: syz-executor.1 Not tainted 5.18.0-rc6-syzkaller-00007-g9be9ed2612b5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================