On Tuesday 08 October 2024 04:21:30 kernel test robot wrote: > Hi Pali, > > kernel test robot noticed the following build warnings: > > [auto build test WARNING on cifs/for-next] > [also build test WARNING on linus/master v6.12-rc2 next-20241004] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Pali-Roh-r/cifs-Add-support-for-parsing-WSL-style-symlinks/20241006-170802 > base: git://git.samba.org/sfrench/cifs-2.6.git for-next > patch link: https://lore.kernel.org/r/20241006090548.30053-1-pali%40kernel.org > patch subject: [PATCH] cifs: Add support for parsing WSL-style symlinks > config: x86_64-randconfig-122-20241008 (https://download.01.org/0day-ci/archive/20241008/202410080458.o4vvmJkR-lkp@xxxxxxxxx/config) > compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff) > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241008/202410080458.o4vvmJkR-lkp@xxxxxxxxx/reproduce) > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > the same patch/commit), kindly add following tags > | Reported-by: kernel test robot <lkp@xxxxxxxxx> > | Closes: https://lore.kernel.org/oe-kbuild-all/202410080458.o4vvmJkR-lkp@xxxxxxxxx/ > > sparse warnings: (new ones prefixed by >>) > >> fs/smb/client/reparse.c:676:45: sparse: sparse: incorrect type in argument 4 (different base types) @@ expected unsigned short [usertype] *pwcs @@ got restricted __le16 [usertype] *[assigned] symname_utf16 @@ > fs/smb/client/reparse.c:676:45: sparse: expected unsigned short [usertype] *pwcs > fs/smb/client/reparse.c:676:45: sparse: got restricted __le16 [usertype] *[assigned] symname_utf16 > > vim +676 fs/smb/client/reparse.c > > 646 > 647 static int parse_reparse_wsl_symlink(struct reparse_wsl_symlink_data_buffer *buf, > 648 struct cifs_sb_info *cifs_sb, > 649 struct cifs_open_info_data *data) > 650 { > 651 int len = le16_to_cpu(buf->ReparseDataLength); > 652 int symname_utf8_len; > 653 __le16 *symname_utf16; > 654 int symname_utf16_len; > 655 > 656 if (len <= sizeof(buf->Flags)) { > 657 cifs_dbg(VFS, "srv returned malformed wsl symlink buffer\n"); > 658 return -EIO; > 659 } > 660 > 661 /* PathBuffer is in UTF-8 but without trailing null-term byte */ > 662 symname_utf8_len = len - sizeof(buf->Flags); > 663 /* > 664 * Check that buffer does not contain null byte > 665 * because Linux cannot process symlink with null byte. > 666 */ > 667 if (strnlen(buf->PathBuffer, symname_utf8_len) != symname_utf8_len) { > 668 cifs_dbg(VFS, "srv returned null byte in wsl symlink target location\n"); > 669 return -EIO; > 670 } > 671 symname_utf16 = kzalloc(symname_utf8_len * 2, GFP_KERNEL); > 672 if (!symname_utf16) > 673 return -ENOMEM; > 674 symname_utf16_len = utf8s_to_utf16s(buf->PathBuffer, symname_utf8_len, > 675 UTF16_LITTLE_ENDIAN, > > 676 symname_utf16, symname_utf8_len * 2); Hello, I'm not sure if there is a real problem or it is just a false-positive report. Please look at it. I saw that in cifs code is common pattern to use __le16* type for UTF-16-LE string. Kernel nls library function utf8s_to_utf16s for output buffer is expecting wchar_t* type, also for the case when it is encoding to UTF-16-LE (requested by UTF16_LITTLE_ENDIAN). And cifs_strndup_from_utf16 for input UTF-16-LE string is using u8* type. So what kind of type for symname_utf16 buffer should be used? It stores UTF-16-LE string. Type u8*, u16*, __le16*, wchar_t* or short*? I guess that it should be possible to mute this report by adding another explicit cast and call utf8s_to_utf16s() with "(wchar_t*)symname_utf16" as 4th parameter. > 677 if (symname_utf16_len < 0) { > 678 kfree(symname_utf16); > 679 return symname_utf16_len; > 680 } > 681 symname_utf16_len *= 2; /* utf8s_to_utf16s() returns number of u16 items, not byte length */ > 682 > 683 data->symlink_target = cifs_strndup_from_utf16((u8 *)symname_utf16, > 684 symname_utf16_len, true, > 685 cifs_sb->local_nls); > 686 kfree(symname_utf16); > 687 if (!data->symlink_target) > 688 return -ENOMEM; > 689 > 690 return 0; > 691 } > 692 > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki
