From f5f111c231f56e56e186c9a61a9d22fb8bf05faa Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Sun, 7 Jul 2019 07:45:42 +1000 Subject: [PATCH] cifs: refactor and clean up arguments in the reparse point parsing Will be helpful as we improve handling of special file types. Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French --- fs/cifs/smb2ops.c | 66 ++++++++++++++++++++++------------------------- 1 file changed, 31 insertions(+), 35 deletions(-) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index c4047ad7b43f..4b0b14946343 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -2383,11 +2383,6 @@ parse_reparse_posix(struct reparse_posix_data *symlink_buf, /* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */ len = le16_to_cpu(symlink_buf->ReparseDataLength); - if (len + sizeof(struct reparse_data_buffer) > plen) { - cifs_dbg(VFS, "srv returned malformed symlink buffer\n"); - return -EINVAL; - } - if (le64_to_cpu(symlink_buf->InodeType) != NFS_SPECFILE_LNK) { cifs_dbg(VFS, "%lld not a supported symlink type\n", le64_to_cpu(symlink_buf->InodeType)); @@ -2437,22 +2432,38 @@ parse_reparse_symlink(struct reparse_symlink_data_buffer *symlink_buf, } static int -parse_reparse_point(struct reparse_symlink_data_buffer *buf, - u32 plen, char **target_path, - struct cifs_sb_info *cifs_sb) +parse_reparse_point(struct reparse_data_buffer *buf, + u32 plen, char **target_path, + struct cifs_sb_info *cifs_sb) { + if (plen < sizeof(struct reparse_data_buffer)) { + cifs_dbg(VFS, "reparse buffer is too small. Must be " + "at least 8 bytes but was %d\n", plen); + return -EIO; + } + + if (plen < le16_to_cpu(buf->ReparseDataLength) + + sizeof(struct reparse_data_buffer)) { + cifs_dbg(VFS, "srv returned invalid reparse buf " + "length: %d\n", plen); + return -EIO; + } + /* See MS-FSCC 2.1.2 */ - if (le32_to_cpu(buf->ReparseTag) == IO_REPARSE_TAG_NFS) - return parse_reparse_posix((struct reparse_posix_data *)buf, + switch (le32_to_cpu(buf->ReparseTag)) { + case IO_REPARSE_TAG_NFS: + return parse_reparse_posix( + (struct reparse_posix_data *)buf, plen, target_path, cifs_sb); - else if (le32_to_cpu(buf->ReparseTag) == IO_REPARSE_TAG_SYMLINK) - return parse_reparse_symlink(buf, plen, target_path, - cifs_sb); - - cifs_dbg(VFS, "srv returned invalid symlink buffer tag:%d\n", - le32_to_cpu(buf->ReparseTag)); - - return -EIO; + case IO_REPARSE_TAG_SYMLINK: + return parse_reparse_symlink( + (struct reparse_symlink_data_buffer *)buf, + plen, target_path, cifs_sb); + default: + cifs_dbg(VFS, "srv returned unknown symlink buffer " + "tag:0x%08x\n", le32_to_cpu(buf->ReparseTag)); + return -EOPNOTSUPP; + } } #define SMB2_SYMLINK_STRUCT_SIZE \ @@ -2581,23 +2592,8 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon, goto querty_exit; } - if (plen < 8) { - cifs_dbg(VFS, "reparse buffer is too small. Must be " - "at least 8 bytes but was %d\n", plen); - rc = -EIO; - goto querty_exit; - } - - if (plen < le16_to_cpu(reparse_buf->ReparseDataLength) + 8) { - cifs_dbg(VFS, "srv returned invalid reparse buf " - "length: %d\n", plen); - rc = -EIO; - goto querty_exit; - } - - rc = parse_reparse_point( - (struct reparse_symlink_data_buffer *)reparse_buf, - plen, target_path, cifs_sb); + rc = parse_reparse_point(reparse_buf, plen, target_path, + cifs_sb); goto querty_exit; }