2013/9/27 Steve French <smfrench@xxxxxxxxx>:
> I have to make some minor fixes to the patch below to account for
> little endian specific fields in symlink reparse point structure, but
> it does fix the problem ("ls -l" to windows 8 or later share which has
> multiple types of reparse points in the same directory, not all of
> which are NTFS symlinks).
>
> From: Steve French <smfrench@xxxxxxxxx>
> Date: Thu, 26 Sep 2013 19:49:14 -0500
> Subject: [PATCH] [CIFS] do not treat non-symlink reparse points as valid
> symlinks
>
> Windows 8 and later can create NFS symlinks (within reparse points)
> which we were assuming were normal NTFS symlinks and thus reporting
> corrupt paths for. Add check for reparse points to make sure that
> they really are normal symlinks before we try to parse the pathname.
>
> This fixes commit d244bf2dfbebfded05f494ffd53659fa7b1e32c1
> which implemented follow link for non-Unix CIFS mounts
>
> CC: Stable <stable@xxxxxxxxxx>
> Reviewed-by: Andrew Bartlett <abartlet@xxxxxxxxx>
> Signed-off-by: Steve French <smfrench@xxxxxxxxx>
> ---
> fs/cifs/cifspdu.h | 2 +-
> fs/cifs/cifssmb.c | 9 +++++++--
> fs/cifs/smbfsctl.h | 14 ++++++++++++++
> 3 files changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
> index a630475..5f295f3 100644
> --- a/fs/cifs/cifspdu.h
> +++ b/fs/cifs/cifspdu.h
> @@ -1491,7 +1491,7 @@ struct file_notify_information {
> __u8 FileName[0];
> } __attribute__((packed));
>
> -struct reparse_data {
> +struct reparse_symlink_data {
> __u32 ReparseTag;
> __u16 ReparseDataLength;
> __u16 Reserved;
> diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> index 4baf359..0bf7635 100644
> --- a/fs/cifs/cifssmb.c
> +++ b/fs/cifs/cifssmb.c
> @@ -3088,7 +3088,7 @@ 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;
> __u32 data_offset, data_count;
> char *end_of_smb;
>
> @@ -3137,12 +3137,17 @@ 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->ReparseTag != IO_REPARSE_TAG_SYMLINK) {
> + rc = -EOPNOTSUPP;
> + goto qreparse_out;
> + }
> +
Shouldn't we do the same things for SMB2?
> if ((reparse_buf->PathBuffer + reparse_buf->PrintNameOffset +
> reparse_buf->PrintNameLength) > end_of_smb) {
> cifs_dbg(FYI, "reparse buf beyond SMB\n");
> diff --git a/fs/cifs/smbfsctl.h b/fs/cifs/smbfsctl.h
> index d952ee4..3a10e1c 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 0xA0000014
>
> /* fsctl flags */
> /* If Flags is set to this value, the request is an FSCTL not ioctl request */
> --
> 1.7.11.7
>
>
> --
> Thanks,
>
> Steve
> --
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--
Best regards,
Pavel Shilovsky.
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