================================================================== BUG: KCSAN: data-race in ext4_alloc_da_blocks / ext4_da_reserve_space write to 0xffff888105d95f20 of 4 bytes by task 29750 on cpu 1: ext4_da_reserve_space+0x147/0x200 fs/ext4/inode.c:1493 ext4_insert_delayed_block fs/ext4/inode.c:1658 [inline] ext4_da_map_blocks fs/ext4/inode.c:1772 [inline] ext4_da_get_block_prep+0x512/0x9b0 fs/ext4/inode.c:1836 __block_write_begin_int+0x4a2/0x1060 fs/buffer.c:2011 __block_write_begin+0x2b/0x40 fs/buffer.c:2061 ext4_da_write_begin+0x4c8/0x820 fs/ext4/inode.c:3020 generic_perform_write+0x196/0x3a0 mm/filemap.c:3643 ext4_buffered_write_iter+0x2f2/0x3f0 fs/ext4/file.c:269 ext4_file_write_iter+0x2e7/0x11d0 fs/ext4/file.c:502 call_write_iter include/linux/fs.h:2116 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x40a/0x750 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 do_splice_direct+0xf5/0x170 fs/splice.c:979 do_sendfile+0x773/0xda0 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1325 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff888105d95f20 of 4 bytes by task 29741 on cpu 0: ext4_alloc_da_blocks+0x1d/0xd0 fs/ext4/inode.c:3132 ext4_release_file+0x5b/0x1d0 fs/ext4/file.c:141 __fput+0x25b/0x4e0 fs/file_table.c:280 ____fput+0x11/0x20 fs/file_table.c:313 task_work_run+0xae/0x130 kernel/task_work.c:161 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x156/0x190 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 29741 Comm: syz-executor.5 Not tainted 5.12.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================