Static code analysis reported a possible null pointer dereference
in my last commit:
cifs: Retain old ACEs when converting between mode bits and ACL.
This could happen if the DACL returned by the server is corrupted.
We were trying to continue by assuming that the file has empty DACL.
We should bail out with an error instead.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Rohith Surabattula <rohiths@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
With cifsacl, when a file/dir ownership is transferred (chown/chgrp),
the ACEs in the DACL for that file will need to replace the old owner
SIDs with the new owner SID.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When cifsacl mount option is used, retain the ACEs which
should not be modified during chmod. Following is the approach taken:
1. Retain all explicit (non-inherited) ACEs, unless the SID is one
of owner/group/everyone/authenticated-users. We're going to set new
ACEs for these SIDs anyways.
2. At the end of the list of explicit ACEs, place the new list of
ACEs obtained by necessary conversion/encoding.
3. Once the converted/encoded ACEs are set, copy all the remaining
ACEs (inherited) into the new ACL.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Add SYSTEM_SECURITY access flag and use with smb2 when opening
files for getting/setting SACLs. Add "system.cifs_ntsd_full"
extended attribute to allow user-space access to the functionality.
Avoid multiple server calls when setting owner, DACL, and SACL.
Signed-off-by: Boris Protopopov <pboris@amazon.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We can already access these from cifs_sb->ctx so we no longer need
a local copy in cifs_sb.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
For the cifsacl mount option, we did not support sticky bits.
With this patch, we do support it, by setting the DELETE_CHILD perm
on the directory only for the owner user. When sticky bit is not
enabled, allow DELETE_CHILD perm for everyone.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
With the "cifsacl" mount option, the mode bits set on the file/dir
is converted to corresponding ACEs in DACL. However, only the
ALLOWED ACEs were being set for "owner" and "group" SIDs. Since
owner is a subset of group, and group is a subset of
everyone/world SID, in order to properly emulate unix perm groups,
we need to add DENIED ACEs. If we don't do that, "owner" and "group"
SIDs could get more access rights than they should. Which is what
was happening. This fixes it.
We try to keep the "preferred" order of ACEs, i.e. DENYs followed
by ALLOWs. However, for a small subset of cases we cannot
maintain the preferred order. In that case, we'll end up with the
DENY ACE for group after the ALLOW for the owner.
If owner SID == group SID, use the more restrictive
among the two perm bits and convert them to ACEs.
Also, for reverse mapping, i.e. to convert ACL to unix perm bits,
for the "others" bits, we needed to add the masked bits of the
owner and group masks to others mask.
Updated version of patch fixes a problem noted by the kernel
test robot.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We were setting the uid/gid to the default in each dir entry
in the parsing of the POSIX query dir response, rather
than attempting to map the user and group SIDs returned by
the server to well known SIDs (or upcall if not found).
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Link: https://lore.kernel.org/r/20200627103125.71828-1-grandmaster@al2klimov.de
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
idsfromsid was ignored in chown and chgrp causing it to fail
when upcalls were not configured for lookup. idsfromsid allows
mapping users when setting user or group ownership using
"special SID" (reserved for this). Add support for chmod and chgrp
when idsfromsid mount option is enabled.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Currently idsfromsid mount option allows querying owner information from the
special sids used to represent POSIX uids and gids but needed changes to
populate the security descriptor context with the owner information when
idsfromsid mount option was used.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
fix warning [-Wunused-but-set-variable] at variable 'rc',
keeping the code readable.
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
A number of the debug statements output file or directory mode
in hex. Change these to print using octal.
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When "backup intent" is requested on the mount (e.g. backupuid or
backupgid mount options), the corresponding flag was missing from
some of the operations.
Change all operations to use the macro cifs_create_options() to
set the backup intent flag if needed.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When mounting with "modefromsid" mount parm most servers will require
that some default permissions are given to users in the ACL on newly
created files, files created with the new 'sd context' - when passing in
an sd context on create, permissions are not inherited from the parent
directory, so in addition to the ACE with the special SID which contains
the mode, we also must pass in an ACE allowing users to access the file
(GENERIC_ALL for authenticated users seemed like a reasonable default,
although later we could allow a mount option or config switch to make
it GENERIC_ALL for EVERYONE special sid).
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-By: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
When using the special SID to store the mode bits in an ACE (See
http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx)
which is enabled with mount parm "modefromsid" we were not
passing in the mode via SMB3 create (although chmod was enabled).
SMB3 create allows a security descriptor context to be passed
in (which is more atomic and thus preferable to setting the mode
bits after create via a setinfo).
This patch enables setting the mode bits on create when using
modefromsid mount option. In addition it fixes an endian
error in the definition of the Control field flags in the SMB3
security descriptor. It also makes the ACE type of the special
SID better match the documentation (and behavior of servers
which use this to store mode bits in SMB3 ACLs).
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
fs/cifs/cifsacl.c:43:30: warning:
sid_user defined but not used [-Wunused-const-variable=]
It is never used, so remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
DACL should start with mode ACE first but we are putting it at the
end. reorder them to put it first.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When mounting with "modefromsid" retrieve mode bits from
special SID (S-1-5-88-3) on stat. Subsequent patch will fix
setattr (chmod) to save mode bits in S-1-5-88-3-<mode>
Note that when an ACE matching S-1-5-88-3 is not found, we
default the mode to an approximation based on the owner, group
and everyone permissions (as with the "cifsacl" mount option).
See See e.g.
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/hh509017(v=ws.10)
Signed-off-by: Steve French <stfrench@microsoft.com>
Replace the uid/gid/perm permissions checking on a key with an ACL to allow
the SETATTR and SEARCH permissions to be split. This will also allow a
greater range of subjects to represented.
============
WHY DO THIS?
============
The problem is that SETATTR and SEARCH cover a slew of actions, not all of
which should be grouped together.
For SETATTR, this includes actions that are about controlling access to a
key:
(1) Changing a key's ownership.
(2) Changing a key's security information.
(3) Setting a keyring's restriction.
And actions that are about managing a key's lifetime:
(4) Setting an expiry time.
(5) Revoking a key.
and (proposed) managing a key as part of a cache:
(6) Invalidating a key.
Managing a key's lifetime doesn't really have anything to do with
controlling access to that key.
Expiry time is awkward since it's more about the lifetime of the content
and so, in some ways goes better with WRITE permission. It can, however,
be set unconditionally by a process with an appropriate authorisation token
for instantiating a key, and can also be set by the key type driver when a
key is instantiated, so lumping it with the access-controlling actions is
probably okay.
As for SEARCH permission, that currently covers:
(1) Finding keys in a keyring tree during a search.
(2) Permitting keyrings to be joined.
(3) Invalidation.
But these don't really belong together either, since these actions really
need to be controlled separately.
Finally, there are number of special cases to do with granting the
administrator special rights to invalidate or clear keys that I would like
to handle with the ACL rather than key flags and special checks.
===============
WHAT IS CHANGED
===============
The SETATTR permission is split to create two new permissions:
(1) SET_SECURITY - which allows the key's owner, group and ACL to be
changed and a restriction to be placed on a keyring.
(2) REVOKE - which allows a key to be revoked.
The SEARCH permission is split to create:
(1) SEARCH - which allows a keyring to be search and a key to be found.
(2) JOIN - which allows a keyring to be joined as a session keyring.
(3) INVAL - which allows a key to be invalidated.
The WRITE permission is also split to create:
(1) WRITE - which allows a key's content to be altered and links to be
added, removed and replaced in a keyring.
(2) CLEAR - which allows a keyring to be cleared completely. This is
split out to make it possible to give just this to an administrator.
(3) REVOKE - see above.
Keys acquire ACLs which consist of a series of ACEs, and all that apply are
unioned together. An ACE specifies a subject, such as:
(*) Possessor - permitted to anyone who 'possesses' a key
(*) Owner - permitted to the key owner
(*) Group - permitted to the key group
(*) Everyone - permitted to everyone
Note that 'Other' has been replaced with 'Everyone' on the assumption that
you wouldn't grant a permit to 'Other' that you wouldn't also grant to
everyone else.
Further subjects may be made available by later patches.
The ACE also specifies a permissions mask. The set of permissions is now:
VIEW Can view the key metadata
READ Can read the key content
WRITE Can update/modify the key content
SEARCH Can find the key by searching/requesting
LINK Can make a link to the key
SET_SECURITY Can change owner, ACL, expiry
INVAL Can invalidate
REVOKE Can revoke
JOIN Can join this keyring
CLEAR Can clear this keyring
The KEYCTL_SETPERM function is then deprecated.
The KEYCTL_SET_TIMEOUT function then is permitted if SET_SECURITY is set,
or if the caller has a valid instantiation auth token.
The KEYCTL_INVALIDATE function then requires INVAL.
The KEYCTL_REVOKE function then requires REVOKE.
The KEYCTL_JOIN_SESSION_KEYRING function then requires JOIN to join an
existing keyring.
The JOIN permission is enabled by default for session keyrings and manually
created keyrings only.
======================
BACKWARD COMPATIBILITY
======================
To maintain backward compatibility, KEYCTL_SETPERM will translate the
permissions mask it is given into a new ACL for a key - unless
KEYCTL_SET_ACL has been called on that key, in which case an error will be
returned.
It will convert possessor, owner, group and other permissions into separate
ACEs, if each portion of the mask is non-zero.
SETATTR permission turns on all of INVAL, REVOKE and SET_SECURITY. WRITE
permission turns on WRITE, REVOKE and, if a keyring, CLEAR. JOIN is turned
on if a keyring is being altered.
The KEYCTL_DESCRIBE function translates the ACL back into a permissions
mask to return depending on possessor, owner, group and everyone ACEs.
It will make the following mappings:
(1) INVAL, JOIN -> SEARCH
(2) SET_SECURITY -> SETATTR
(3) REVOKE -> WRITE if SETATTR isn't already set
(4) CLEAR -> WRITE
Note that the value subsequently returned by KEYCTL_DESCRIBE may not match
the value set with KEYCTL_SETATTR.
=======
TESTING
=======
This passes the keyutils testsuite for all but a couple of tests:
(1) tests/keyctl/dh_compute/badargs: The first wrong-key-type test now
returns EOPNOTSUPP rather than ENOKEY as READ permission isn't removed
if the type doesn't have ->read(). You still can't actually read the
key.
(2) tests/keyctl/permitting/valid: The view-other-permissions test doesn't
work as Other has been replaced with Everyone in the ACL.
Signed-off-by: David Howells <dhowells@redhat.com>
Create an ops variable to store tcon->ses->server->ops and cache
indirections and reduce code size a trivial bit.
$ size fs/cifs/cifsacl.o*
text data bss dec hex filename
5338 136 8 5482 156a fs/cifs/cifsacl.o.new
5371 136 8 5515 158b fs/cifs/cifsacl.o.old
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
New mount option "idsfromsid" indicates to cifs.ko that
it should try to retrieve the uid and gid owner fields
from special sids. This patch adds the code to parse the owner
sids in the ACL to see if they match, and if so populate the
uid and/or gid from them. This is faster than upcalling for
them and asking winbind, and is a fairly common case, and is
also helpful when cifs.upcall and idmapping is not configured.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Add a facility whereby proposed new links to be added to a keyring can be
vetted, permitting them to be rejected if necessary. This can be used to
block public keys from which the signature cannot be verified or for which
the signature verification fails. It could also be used to provide
blacklisting.
This affects operations like add_key(), KEYCTL_LINK and KEYCTL_INSTANTIATE.
To this end:
(1) A function pointer is added to the key struct that, if set, points to
the vetting function. This is called as:
int (*restrict_link)(struct key *keyring,
const struct key_type *key_type,
unsigned long key_flags,
const union key_payload *key_payload),
where 'keyring' will be the keyring being added to, key_type and
key_payload will describe the key being added and key_flags[*] can be
AND'ed with KEY_FLAG_TRUSTED.
[*] This parameter will be removed in a later patch when
KEY_FLAG_TRUSTED is removed.
The function should return 0 to allow the link to take place or an
error (typically -ENOKEY, -ENOPKG or -EKEYREJECTED) to reject the
link.
The pointer should not be set directly, but rather should be set
through keyring_alloc().
Note that if called during add_key(), preparse is called before this
method, but a key isn't actually allocated until after this function
is called.
(2) KEY_ALLOC_BYPASS_RESTRICTION is added. This can be passed to
key_create_or_update() or key_instantiate_and_link() to bypass the
restriction check.
(3) KEY_FLAG_TRUSTED_ONLY is removed. The entire contents of a keyring
with this restriction emplaced can be considered 'trustworthy' by
virtue of being in the keyring when that keyring is consulted.
(4) key_alloc() and keyring_alloc() take an extra argument that will be
used to set restrict_link in the new key. This ensures that the
pointer is set before the key is published, thus preventing a window
of unrestrictedness. Normally this argument will be NULL.
(5) As a temporary affair, keyring_restrict_trusted_only() is added. It
should be passed to keyring_alloc() as the extra argument instead of
setting KEY_FLAG_TRUSTED_ONLY on a keyring. This will be replaced in
a later patch with functions that look in the appropriate places for
authoritative keys.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Replace all __constant_foo to foo() except in smb2status.h (1700 lines to
update).
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Steve French <sfrench@samba.org>
Cc: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A previous patch added a ->match_preparse() method to the key type. This is
allowed to override the function called by the iteration algorithm.
Therefore, we can just set a default that simply checks for an exact match of
the key description with the original criterion data and allow match_preparse
to override it as needed.
The key_type::match op is then redundant and can be removed, as can the
user_match() function.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
When mounting with smb2/smb3 (e.g. vers=2.1) and cifsacl mount option,
it was trying to get the mode by querying the acl over the cifs
rather than smb2 protocol. This patch makes that protocol
independent and makes cifsacl smb2 mounts return a more intuitive
operation not supported error (until we add a worker function
for smb2_get_acl).
Note that a previous patch fixed getxattr/setxattr for the CIFSACL xattr
which would unconditionally call cifs_get_acl and cifs_set_acl (even when
mounted smb2). I made those protocol independent last week (new protocol
version operations "get_acl" and "set_acl" but did not add an
smb2_get_acl and smb2_set_acl yet so those now simply return EOPNOTSUPP
which at least is better than sending cifs requests on smb2 mount)
The previous patches did not fix the one remaining case though ie
mounting with "cifsacl" when getting mode from acl would unconditionally
end up calling "cifs_get_acl_from_fid" even for smb2 - so made that protocol
independent but to make that protocol independent had to make sure that the callers
were passing the protocol independent handle structure (cifs_fid) instead
of cifs specific _u16 network file handle (ie cifs_fid instead of cifs_fid->fid)
Now mount with smb2 and cifsacl mount options will return EOPNOTSUP (instead
of timing out) and a future patch will add smb2 operations (e.g. get_smb2_acl)
to enable this.
Signed-off-by: Steve French <smfrench@gmail.com>
The get/set ACL xattr support for CIFS ACLs attempts to send old
cifs dialect protocol requests even when mounted with SMB2 or later
dialects. Sending cifs requests on an smb2 session causes problems -
the server drops the session due to the illegal request.
This patch makes CIFS ACL operations protocol specific to fix that.
Attempting to query/set CIFS ACLs for SMB2 will now return
EOPNOTSUPP (until we add worker routines for sending query
ACL requests via SMB2) instead of sending invalid (cifs)
requests.
A separate followon patch will be needed to fix cifs_acl_to_fattr
(which takes a cifs specific u16 fid so can't be abstracted
to work with SMB2 until that is changed) and will be needed
to fix mount problems when "cifsacl" is specified on mount
with e.g. vers=2.1
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
CC: Stable <stable@kernel.org>
Rename CIFSSMBOpen to CIFS_open and make it take
cifs_open_parms structure as a parm.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
It's not obvious from reading the macro names that these macros
are for debugging. Convert the names to a single more typical
kernel style cifs_dbg macro.
cERROR(1, ...) -> cifs_dbg(VFS, ...)
cFYI(1, ...) -> cifs_dbg(FYI, ...)
cFYI(DBG2, ...) -> cifs_dbg(NOISY, ...)
Move the terminating format newline from the macro to the call site.
Add CONFIG_CIFS_DEBUG function cifs_vfs_err to emit the
"CIFS VFS: " prefix for VFS messages.
Size is reduced ~ 1% when CONFIG_CIFS_DEBUG is set (default y)
$ size fs/cifs/cifs.ko*
text data bss dec hex filename
265245 2525 132 267902 4167e fs/cifs/cifs.ko.new
268359 2525 132 271016 422a8 fs/cifs/cifs.ko.old
Other miscellaneous changes around these conversions:
o Miscellaneous typo fixes
o Add terminating \n's to almost all formats and remove them
from the macros to be more kernel style like. A few formats
previously had defective \n's
o Remove unnecessary OOM messages as kmalloc() calls dump_stack
o Coalesce formats to make grep easier,
added missing spaces when coalescing formats
o Use %s, __func__ instead of embedded function name
o Removed unnecessary "cifs: " prefixes
o Convert kzalloc with multiply to kcalloc
o Remove unused cifswarn macro
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
This replaces calls to kmalloc followed by memcpy with a single call to
kmemdup. This was found via make coccicheck.
Signed-off-by: Silviu-Mihai Popescu <silviupopescu1990@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Update id_mode_to_cifs_acl to take a kuid_t and a kgid_t.
Replace NO_CHANGE_32 with INVALID_UID and INVALID_GID, and tests for
NO_CHANGE_32 with uid_valid and gid_valid.
Carefully unpack the value returned from request_key. memcpy the
value into the expected type. The convert the uid/gid into a
kuid/kgid. And then only if the result is a valid kuid or kgid update
fuid/fgid.
Cc: Steve French <smfrench@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
keyring_alloc has been updated to take a kuid_t and kgid_t so
pass GLOBAL_ROOT_UID instead of 0 for the uid and GLOBAL_ROOT_GID
instead of 0 for the gid.
Cc: Steve French <smfrench@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The assumption that sizeof(uid_t) is the same as sizeof(gid_t) is
completely reasonable but since we can verify the condition at
compile time.
Cc: Steve French <smfrench@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull security subsystem updates from James Morris:
"A quiet cycle for the security subsystem with just a few maintenance
updates."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
Smack: create a sysfs mount point for smackfs
Smack: use select not depends in Kconfig
Yama: remove locking from delete path
Yama: add RCU to drop read locking
drivers/char/tpm: remove tasklet and cleanup
KEYS: Use keyring_alloc() to create special keyrings
KEYS: Reduce initial permissions on keys
KEYS: Make the session and process keyrings per-thread
seccomp: Make syscall skipping and nr changes more consistent
key: Fix resource leak
keys: Fix unreachable code
KEYS: Add payload preparsing opportunity prior to key instantiate or update
The authority fields are supposed to be represented by a single 48-bit
value. It's also supposed to represent the value as hex if it's equal to
or greater than 2^32. This is documented in MS-DTYP, section 2.4.2.1.
Also, fix up the max string length to account for this fix.
Acked-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
A SID could potentially be embedded inside of payload.value if there are
no subauthorities, and the arch has 8 byte pointers. Allow for that
possibility there.
While we're at it, rephrase the "embedding" check in terms of
key->payload to allow for the possibility that the union might change
size in the future.
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
It was hardcoded to 192 bytes, which was not enough when the max number
of subauthorities went to 15. Redefine this constant in terms of sizeof
the structs involved, and rename it for better clarity.
While we're at it, remove a couple more unused constants from cifsacl.h.
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Now that we aren't so rigid about the length of the key being passed
in, we need to be a bit more rigorous about checking the length of
the actual data against the claimed length (a'la num_subauths field).
Check for the case where userspace sends us a seemingly valid key
with a num_subauths field that goes beyond the end of the array. If
that happens, return -EIO and invalidate the key.
Also change the other places where we check for malformed keys in this
code to invalidate the key as well.
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
The cifs.idmap keytype always allocates memory to hold the payload from
userspace. In the common case where we're translating a SID to a UID or
GID, we're allocating memory to hold something that's less than or equal
to the size of a pointer.
When the payload is the same size as a pointer or smaller, just store
it in the payload.value union member instead. That saves us an extra
allocation on the sid_to_id upcall.
Note that we have to take extra care to check the datalen when we
go to dereference the .data pointer in the union, but the callers
now check that as a matter of course anyway.
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
The cifs.idmap handling code currently causes the kernel to cache the
data from userspace twice. It first looks in a rbtree to see if there is
a matching entry for the given id. If there isn't then it calls
request_key which then checks its cache and then calls out to userland
if it doesn't have one. If the userland program establishes a mapping
and downcalls with that info, it then gets cached in the keyring and in
this rbtree.
Aside from the double memory usage and the performance penalty in doing
all of these extra copies, there are some nasty bugs in here too. The
code declares four rbtrees and spinlocks to protect them, but only seems
to use two of them. The upshot is that the same tree is used to hold
(eg) uid:sid and sid:uid mappings. The comparitors aren't equipped to
deal with that.
I think we'd be best off to remove a layer of caching in this code. If
this was originally done for performance reasons, then that really seems
like a premature optimization.
This patch does that -- it removes the rbtrees and the locks that
protect them and simply has the code do a request_key call on each call
into sid_to_id and id_to_sid. This greatly simplifies this code and
should roughly halve the memory utilization from using the idmapping
code.
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
...and make those symbols static in cifsacl.c. Nothing outside
of that file refers to them.
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
The format specifiers are for signed values, but these are unsigned.
Given that '-' is a delimiter between fields, I don't think you'd get
what you'd expect if you got a value here that would overflow the sign
bit.
The version and authority fields are 8 bit values so use a "hh" length
modifier there. The subauths are 32 bit values, so there's no need to
use a "l" length modifier there.
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
According to several places on the Internet and the samba winbind code,
this is hard limited to 15 in windows, not 5. This does balloon out
the allocation of each by 40 bytes, but I don't see any alternative.
Also, rename it to SID_MAX_SUB_AUTHORITIES to match the alleged name
of this constant in the windows header files
Finally, rename SIDLEN to SID_STRING_MAX, fix the value to reflect
the change to SID_MAX_SUB_AUTHORITIES and document how it was
determined.
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Shyam Prasad N