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[CIFS] When mandatory encryption on share, fail mount

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When mandatory encryption is configured in samba server on a
    share (smb.conf parameter "smb encrypt = mandatory") the
    server will hang up the tcp session when we try to send
    the first frame after the tree connect if it is not a
    QueryFSUnixInfo, this causes cifs mount to hang (it must
    be killed with ctl-c).  Move the QueryFSUnixInfo call
    earlier in the mount sequence, and check whether the SetFSUnixInfo
    fails due to mandatory encryption so we can return a sensible
    error (EACCES) on mount.

    In a future patch (for 2.6.40) we will support mandatory
    encryption.

CC: Stable <stable@kernel.org>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Steve French 2011-05-26 18:38:54 +00:00
parent fa2989f447
commit 6848b7334b
1 changed files with 22 additions and 9 deletions
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31
fs/cifs/connect.c
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@ -2530,7 +2530,7 @@ void reset_cifs_unix_caps(int xid, struct cifsTconInfo *tcon,
if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
__u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
cFYI(1, "unix caps which server supports %lld", cap);
/* check for reconnect case in which we do not
want to change the mount behavior if we can avoid it */
if (vol_info == NULL) {
@ -2548,6 +2548,9 @@ void reset_cifs_unix_caps(int xid, struct cifsTconInfo *tcon,
}
}
if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
cERROR(1, "per-share encryption not supported yet");
cap &= CIFS_UNIX_CAP_MASK;
if (vol_info && vol_info->no_psx_acl)
cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
@ -2596,6 +2599,10 @@ void reset_cifs_unix_caps(int xid, struct cifsTconInfo *tcon,
cFYI(1, "very large read cap");
if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
cFYI(1, "very large write cap");
if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
cFYI(1, "transport encryption cap");
if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
cFYI(1, "mandatory transport encryption cap");
#endif /* CIFS_DEBUG2 */
if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
if (vol_info == NULL) {
@ -3022,20 +3029,26 @@ try_mount_again:
goto remote_path_check;
}
/* tell server which Unix caps we support */
if (tcon->ses->capabilities & CAP_UNIX) {
/* reset of caps checks mount to see if unix extensions
disabled for just this mount */
reset_cifs_unix_caps(xid, tcon, sb, volume_info);
if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
(le64_to_cpu(tcon->fsUnixInfo.Capability) &
CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
rc = -EACCES;
goto mount_fail_check;
}
} else
tcon->unix_ext = 0; /* server does not support them */
/* do not care if following two calls succeed - informational */
if (!tcon->ipc) {
CIFSSMBQFSDeviceInfo(xid, tcon);
CIFSSMBQFSAttributeInfo(xid, tcon);
}
/* tell server which Unix caps we support */
if (tcon->ses->capabilities & CAP_UNIX)
/* reset of caps checks mount to see if unix extensions
disabled for just this mount */
reset_cifs_unix_caps(xid, tcon, sb, volume_info);
else
tcon->unix_ext = 0; /* server does not support them */
/* convert forward to back slashes in prepath here if needed */
if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) == 0)
convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));