3 files changed, 71 insertions, 14 deletions

diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index a630475e421c..08f9dfb1a894 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -1491,15 +1491,30 @@ struct file_notify_information {
         __u8  FileName[0];
 } __attribute__((packed));
 
-struct reparse_data {
-        __u32   ReparseTag;
-        __u16   ReparseDataLength;
+/* For IO_REPARSE_TAG_SYMLINK */
+struct reparse_symlink_data {
+        __le32  ReparseTag;
+        __le16  ReparseDataLength;
         __u16   Reserved;
-        __u16   SubstituteNameOffset;
-        __u16   SubstituteNameLength;
-        __u16   PrintNameOffset;
-        __u16   PrintNameLength;
-        __u32   Flags;
+        __le16  SubstituteNameOffset;
+        __le16  SubstituteNameLength;
+        __le16  PrintNameOffset;
+        __le16  PrintNameLength;
+        __le32  Flags;
+        char    PathBuffer[0];
+} __attribute__((packed));
+
+/* For IO_REPARSE_TAG_NFS */
+#define NFS_SPECFILE_LNK        0x00000000014B4E4C
+#define NFS_SPECFILE_CHR        0x0000000000524843
+#define NFS_SPECFILE_BLK        0x00000000004B4C42
+#define NFS_SPECFILE_FIFO       0x000000004F464946
+#define NFS_SPECFILE_SOCK       0x000000004B434F53
+struct reparse_posix_data {
+        __le32  ReparseTag;
+        __le16  ReparseDataLength;
+        __u16   Reserved;
+        __le64  InodeType; /* LNK, FIFO, CHR etc. */
         char    PathBuffer[0];
 } __attribute__((packed));
 
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 4baf35949b51..ccd31ab815d4 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -3088,7 +3088,8 @@ CIFSSMBQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
         bool is_unicode;
         unsigned int sub_len;
         char *sub_start;
-        struct reparse_data *reparse_buf;
+        struct reparse_symlink_data *reparse_buf;
+        struct reparse_posix_data *posix_buf;
         __u32 data_offset, data_count;
         char *end_of_smb;
 
@@ -3137,20 +3138,47 @@ CIFSSMBQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
                 goto qreparse_out;
         }
         end_of_smb = 2 + get_bcc(&pSMBr->hdr) + (char *)&pSMBr->ByteCount;
-        reparse_buf = (struct reparse_data *)
+        reparse_buf = (struct reparse_symlink_data *)
                                 ((char *)&pSMBr->hdr.Protocol + data_offset);
         if ((char *)reparse_buf >= end_of_smb) {
                 rc = -EIO;
                 goto qreparse_out;
         }
-        if ((reparse_buf->PathBuffer + reparse_buf->PrintNameOffset +
-                                reparse_buf->PrintNameLength) > end_of_smb) {
+        if (reparse_buf->ReparseTag == cpu_to_le32(IO_REPARSE_TAG_NFS)) {
+                cifs_dbg(FYI, "NFS style reparse tag\n");
+                posix_buf =  (struct reparse_posix_data *)reparse_buf;
+
+                if (posix_buf->InodeType != cpu_to_le64(NFS_SPECFILE_LNK)) {
+                        cifs_dbg(FYI, "unsupported file type 0x%llx\n",
+                                 le64_to_cpu(posix_buf->InodeType));
+                        rc = -EOPNOTSUPP;
+                        goto qreparse_out;
+                }
+                is_unicode = true;
+                sub_len = le16_to_cpu(reparse_buf->ReparseDataLength);
+                if (posix_buf->PathBuffer + sub_len > end_of_smb) {
+                        cifs_dbg(FYI, "reparse buf beyond SMB\n");
+                        rc = -EIO;
+                        goto qreparse_out;
+                }
+                *symlinkinfo = cifs_strndup_from_utf16(posix_buf->PathBuffer,
+                                sub_len, is_unicode, nls_codepage);
+                goto qreparse_out;
+        } else if (reparse_buf->ReparseTag !=
+                        cpu_to_le32(IO_REPARSE_TAG_SYMLINK)) {
+                rc = -EOPNOTSUPP;
+                goto qreparse_out;
+        }
+
+        /* Reparse tag is NTFS symlink */
+        sub_start = le16_to_cpu(reparse_buf->SubstituteNameOffset) +
+                                reparse_buf->PathBuffer;
+        sub_len = le16_to_cpu(reparse_buf->SubstituteNameLength);
+        if (sub_start + sub_len > end_of_smb) {
                 cifs_dbg(FYI, "reparse buf beyond SMB\n");
                 rc = -EIO;
                 goto qreparse_out;
         }
-        sub_start = reparse_buf->SubstituteNameOffset + reparse_buf->PathBuffer;
-        sub_len = reparse_buf->SubstituteNameLength;
         if (pSMBr->hdr.Flags2 & SMBFLG2_UNICODE)
                 is_unicode = true;
         else
diff --git a/fs/cifs/smbfsctl.h b/fs/cifs/smbfsctl.h
index d952ee48f4dc..a4b2391fe66e 100644
--- a/fs/cifs/smbfsctl.h
+++ b/fs/cifs/smbfsctl.h
@@ -97,9 +97,23 @@
 #define FSCTL_QUERY_NETWORK_INTERFACE_INFO 0x001401FC /* BB add struct */
 #define FSCTL_SRV_READ_HASH          0x001441BB /* BB add struct */
 
+/* See FSCC 2.1.2.5 */
 #define IO_REPARSE_TAG_MOUNT_POINT   0xA0000003
 #define IO_REPARSE_TAG_HSM           0xC0000004
 #define IO_REPARSE_TAG_SIS           0x80000007
+#define IO_REPARSE_TAG_HSM2          0x80000006
+#define IO_REPARSE_TAG_DRIVER_EXTENDER 0x80000005
+/* Used by the DFS filter. See MS-DFSC */
+#define IO_REPARSE_TAG_DFS           0x8000000A
+/* Used by the DFS filter See MS-DFSC */
+#define IO_REPARSE_TAG_DFSR          0x80000012
+#define IO_REPARSE_TAG_FILTER_MANAGER 0x8000000B
+/* See section MS-FSCC 2.1.2.4 */
+#define IO_REPARSE_TAG_SYMLINK       0xA000000C
+#define IO_REPARSE_TAG_DEDUP         0x80000013
+#define IO_REPARSE_APPXSTREAM        0xC0000014
+/* NFS symlinks, Win 8/SMB3 and later */
+#define IO_REPARSE_TAG_NFS           0x80000014
 
 /* fsctl flags */
 /* If Flags is set to this value, the request is an FSCTL not ioctl request */