tree: https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git idmapped_mounts head: 68489ddb268414e49a819222cd2cd853b4e676d8 commit: e1ad57afed599152f4681d1ed69abdfd4854b105 [16/42] xattr: handle idmapped mounts config: arm-randconfig-r022-20210120 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 22b68440e1647e16b5ee24b924986207173c02d1) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git/commit/... git remote add brauner https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git git fetch --no-tags brauner idmapped_mounts git checkout e1ad57afed599152f4681d1ed69abdfd4854b105 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): mnt_drop_write_file(f.file); ^ fs/xattr.c:623:2: note: previous statement is here if (!error) ^ 1 warning generated. vim +/if +627 fs/xattr.c ^1da177e4c3f4152 Linus Torvalds 2005-04-16 612 64fd1de3d821659a Heiko Carstens 2009-01-14 613 SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, 64fd1de3d821659a Heiko Carstens 2009-01-14 614 const void __user *,value, size_t, size, int, flags) ^1da177e4c3f4152 Linus Torvalds 2005-04-16 615 { 2903ff019b346ab8 Al Viro 2012-08-28 616 struct fd f = fdget(fd); ^1da177e4c3f4152 Linus Torvalds 2005-04-16 617 int error = -EBADF; ^1da177e4c3f4152 Linus Torvalds 2005-04-16 618 2903ff019b346ab8 Al Viro 2012-08-28 619 if (!f.file) ^1da177e4c3f4152 Linus Torvalds 2005-04-16 620 return error; 9f45f5bf302daad6 Al Viro 2014-10-31 621 audit_file(f.file); 6742cee043532310 Miklos Szeredi 2018-07-18 622 error = mnt_want_write_file(f.file); e1ad57afed599152 Tycho Andersen 2021-01-12 623 if (!error) e1ad57afed599152 Tycho Andersen 2021-01-12 624 error = setxattr(file_mnt_user_ns(f.file), e1ad57afed599152 Tycho Andersen 2021-01-12 625 f.file->f_path.dentry, name, e1ad57afed599152 Tycho Andersen 2021-01-12 626 value, size, flags); 6742cee043532310 Miklos Szeredi 2018-07-18 @627 mnt_drop_write_file(f.file); 2903ff019b346ab8 Al Viro 2012-08-28 628 fdput(f); ^1da177e4c3f4152 Linus Torvalds 2005-04-16 629 return error; ^1da177e4c3f4152 Linus Torvalds 2005-04-16 630 } ^1da177e4c3f4152 Linus Torvalds 2005-04-16 631 :::::: The code at line 627 was first introduced by commit :::::: 6742cee04353231015ddbe7e8b404ac9c1eb4473 Revert "ovl: don't allow writing ioctl on lower layer" :::::: TO: Miklos Szeredi <mszeredi(a)redhat.com&gt; :::::: CC: Miklos Szeredi <mszeredi(a)redhat.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org