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path: root/fs/cifs/cifsacl.c
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* cifs: If a corrupted DACL is returned by the server, bail out.Shyam Prasad N2021-02-241-2/+2
| | | | | | | | | | | | | | | 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>
* cifs: cleanup a few le16 vs. le32 uses in cifsacl.cSteve French2021-02-221-3/+3
| | | | | | Cleanup some minor sparse warnings in cifsacl.c Signed-off-by: Steve French <stfrench@microsoft.com>
* cifs: Change SIDs in ACEs while transferring file ownership.Shyam Prasad N2021-02-221-47/+92
| | | | | | | | | 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>
* cifs: Retain old ACEs when converting between mode bits and ACL.Shyam Prasad N2021-02-221-47/+223
| | | | | | | | | | | | | | | | 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>
* SMB3: Add support for getting and setting SACLsBoris Protopopov2020-12-181-6/+9
| | | | | | | | | | 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>
* cifs: remove [gu]id/backup[gu]id/file_mode/dir_mode from cifs_sbRonnie Sahlberg2020-12-141-3/+4
| | | | | | | | 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>
* cifs: Enable sticky bit with cifsacl mount option.Shyam Prasad N2020-12-131-11/+30
| | | | | | | | | | 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>
* cifs: Fix unix perm bits to cifsacl conversion for "other" bits.Shyam Prasad N2020-12-131-69/+143
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* cifs: fix a memleak with modefromsidNamjae Jeon2020-11-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kmemleak reported a memory leak allocated in query_info() when cifs is working with modefromsid. backtrace: [<00000000aeef6a1e>] slab_post_alloc_hook+0x58/0x510 [<00000000b2f7a440>] __kmalloc+0x1a0/0x390 [<000000006d470ebc>] query_info+0x5b5/0x700 [cifs] [<00000000bad76ce0>] SMB2_query_acl+0x2b/0x30 [cifs] [<000000001fa09606>] get_smb2_acl_by_path+0x2f3/0x720 [cifs] [<000000001b6ebab7>] get_smb2_acl+0x75/0x90 [cifs] [<00000000abf43904>] cifs_acl_to_fattr+0x13b/0x1d0 [cifs] [<00000000a5372ec3>] cifs_get_inode_info+0x4cd/0x9a0 [cifs] [<00000000388e0a04>] cifs_revalidate_dentry_attr+0x1cd/0x510 [cifs] [<0000000046b6b352>] cifs_getattr+0x8a/0x260 [cifs] [<000000007692c95e>] vfs_getattr_nosec+0xa1/0xc0 [<00000000cbc7d742>] vfs_getattr+0x36/0x40 [<00000000de8acf67>] vfs_statx_fd+0x4a/0x80 [<00000000a58c6adb>] __do_sys_newfstat+0x31/0x70 [<00000000300b3b4e>] __x64_sys_newfstat+0x16/0x20 [<000000006d8e9c48>] do_syscall_64+0x37/0x80 This patch add missing kfree for pntsd when mounting modefromsid option. Cc: Stable <stable@vger.kernel.org> # v5.4+ Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* SMB3.1.1: Fix ids returned in POSIX query dirSteve French2020-10-201-2/+3
| | | | | | | | | | | 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>
* Replace HTTP links with HTTPS ones: CIFSAlexander A. Klimov2020-07-051-2/+2
| | | | | | | | | | | | | | | | | | | | | 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>
* cifs: fix chown and chgrp when idsfromsid mount option enabledSteve French2020-06-121-15/+42
| | | | | | | | | | | 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>
* smb3: allow uid and gid owners to be set on create with idsfromsid mount optionSteve French2020-06-121-0/+22
| | | | | | | | | | 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>
* fs/cifs: fix gcc warning in sid_to_idQiujun Huang2020-03-221-2/+3
| | | | | | | | 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>
* cifs: Fix mode output in debugging statementsFrank Sorenson2020-02-121-2/+2
| | | | | | | | 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>
* SMB3: Backup intent flag missing from some more opsAmir Goldstein2020-02-031-10/+4
| | | | | | | | | | | | 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>
* smb3: fix default permissions on new files when mounting with modefromsidSteve French2020-01-261-0/+20
| | | | | | | | | | | | | | | | | 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>
* smb3: fix mode passed in on create for modetosid mount optionSteve French2019-12-061-16/+26
| | | | | | | | | | | | | | | | | | | | | 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>
* cifs: remove unused variable 'sid_user'YueHaibing2019-11-251-2/+0
| | | | | | | | | | 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>
* cifs: modefromsid: write mode ACE firstAurelien Aptel2019-09-161-17/+19
| | | | | | | | 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>
* cifs: allow chmod to set mode bits using special sidSteve French2019-09-161-5/+37
| | | | | | | | | | | | When mounting with "modefromsid" set mode bits (chmod) by adding ACE with special SID (S-1-5-88-3-<mode>) to the ACL. Subsequent patch will fix setting default mode on file create and mkdir. 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>
* cifs: get mode bits from special sid on statSteve French2019-09-161-11/+26
| | | | | | | | | | | | | | | 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>
* Revert "Merge tag 'keys-acl-20190703' of ↵Linus Torvalds2019-07-101-24/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" This reverts merge 0f75ef6a9cff49ff612f7ce0578bced9d0b38325 (and thus effectively commits 7a1ade847596 ("keys: Provide KEYCTL_GRANT_PERMISSION") 2e12256b9a76 ("keys: Replace uid/gid/perm permissions checking with an ACL") that the merge brought in). It turns out that it breaks booting with an encrypted volume, and Eric biggers reports that it also breaks the fscrypt tests [1] and loading of in-kernel X.509 certificates [2]. The root cause of all the breakage is likely the same, but David Howells is off email so rather than try to work it out it's getting reverted in order to not impact the rest of the merge window. [1] https://lore.kernel.org/lkml/20190710011559.GA7973@sol.localdomain/ [2] https://lore.kernel.org/lkml/20190710013225.GB7973@sol.localdomain/ Link: https://lore.kernel.org/lkml/CAHk-=wjxoeMJfeBahnWH=9zShKp2bsVy527vo3_y8HfOdhwAAw@mail.gmail.com/ Reported-by: Eric Biggers <ebiggers@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* keys: Replace uid/gid/perm permissions checking with an ACLDavid Howells2019-06-271-4/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* treewide: kmalloc() -> kmalloc_array()Kees Cook2018-06-121-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
* fs/cifs/cifsacl.c Fixes typo in a commentAchilles Gaikwad2018-01-281-1/+1
| | | | | Signed-off-by: Achilles Gaikwad <achillesgaikwad@gmail.com> Signed-off-by: Steve French <smfrench@gmail.com>
* cifs: cifsacl: Use a temporary ops variable to reduce code lengthJoe Perches via samba-technical2017-05-121-16/+14
| | | | | | | | | | | | | | 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>
* CIFS: Retrieve uid and gid from special sid if enabledSteve French2016-10-141-0/+123
| | | | | | | | | | | | | | | 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>
* KEYS: Add a facility to restrict new links into a keyringDavid Howells2016-04-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* KEYS: Merge the type-specific data with the payload dataDavid Howells2015-10-211-13/+12
| | | | | | | | | | | | | | | | | Merge the type-specific data with the payload data into one four-word chunk as it seems pointless to keep them separate. Use user_key_payload() for accessing the payloads of overloaded user-defined keys. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-cifs@vger.kernel.org cc: ecryptfs@vger.kernel.org cc: linux-ext4@vger.kernel.org cc: linux-f2fs-devel@lists.sourceforge.net cc: linux-nfs@vger.kernel.org cc: ceph-devel@vger.kernel.org cc: linux-ima-devel@lists.sourceforge.net
* fs/cifs: remove obsolete __constantFabian Frederick2014-12-101-1/+1
| | | | | | | | | | | 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>
* KEYS: Remove key_type::match in favour of overriding default by match_preparseDavid Howells2014-09-161-1/+0
| | | | | | | | | | | | | | 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>
* [CIFS] Fix cifsacl mounts over smb2 to not call cifsSteve French2014-02-101-9/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* retrieving CIFS ACLs when mounted with SMB2 fails dropping sessionSteve French2014-02-071-4/+24
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* CIFS: Cleanup cifs open codepathPavel Shilovsky2014-01-201-12/+28
| | | | | | | | 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>
* [CIFS] cifs: Rename cERROR and cFYI to cifs_dbgJoe Perches2013-05-041-63/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* fs: cifs: use kmemdup instead of kmalloc + memcpySilviu-Mihai Popescu2013-05-041-2/+1
| | | | | | | | | 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>
* cifs: Use kuids and kgids SID to uid/gid mappingEric W. Biederman2013-02-131-14/+29
| | | | | | | | | | | | | | | 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>
* cifs: Pass GLOBAL_ROOT_UID and GLOBAL_ROOT_GID to keyring_allocEric W. Biederman2013-02-131-1/+2
| | | | | | | | | 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>
* cifs: Use BUILD_BUG_ON to validate uids and gids are the same sizeEric W. Biederman2013-02-131-0/+1
| | | | | | | | | 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>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-12-161-8/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 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
| * Merge branch 'modsign-keys-devel' into security-next-keysDavid Howells2012-10-021-4/+4
| |\ | | | | | | | | | Signed-off-by: David Howells <dhowells@redhat.com>
| | * KEYS: Add payload preparsing opportunity prior to key instantiate or updateDavid Howells2012-09-131-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Give the key type the opportunity to preparse the payload prior to the instantiation and update routines being called. This is done with the provision of two new key type operations: int (*preparse)(struct key_preparsed_payload *prep); void (*free_preparse)(struct key_preparsed_payload *prep); If the first operation is present, then it is called before key creation (in the add/update case) or before the key semaphore is taken (in the update and instantiate cases). The second operation is called to clean up if the first was called. preparse() is given the opportunity to fill in the following structure: struct key_preparsed_payload { char *description; void *type_data[2]; void *payload; const void *data; size_t datalen; size_t quotalen; }; Before the preparser is called, the first three fields will have been cleared, the payload pointer and size will be stored in data and datalen and the default quota size from the key_type struct will be stored into quotalen. The preparser may parse the payload in any way it likes and may store data in the type_data[] and payload fields for use by the instantiate() and update() ops. The preparser may also propose a description for the key by attaching it as a string to the description field. This can be used by passing a NULL or "" description to the add_key() system call or the key_create_or_update() function. This cannot work with request_key() as that required the description to tell the upcall about the key to be created. This, for example permits keys that store PGP public keys to generate their own name from the user ID and public key fingerprint in the key. The instantiate() and update() operations are then modified to look like this: int (*instantiate)(struct key *key, struct key_preparsed_payload *prep); int (*update)(struct key *key, struct key_preparsed_payload *prep); and the new payload data is passed in *prep, whether or not it was preparsed. Signed-off-by: David Howells <dhowells@redhat.com>
| * | KEYS: Use keyring_alloc() to create special keyringsDavid Howells2012-10-021-8/+4
| |/ | | | | | | | | | | | | | | | | Use keyring_alloc() to create special keyrings now that it has a permissions parameter rather than using key_alloc() + key_instantiate_and_link(). Also document and export keyring_alloc() so that modules can use it too. Signed-off-by: David Howells <dhowells@redhat.com>
* | cifs: fix SID binary to string conversionJeff Layton2012-12-111-6/+19
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* | cifs: deal with id_to_sid embedded sid reply corner caseJeff Layton2012-12-081-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | cifs: fix hardcoded default security descriptor lengthJeff Layton2012-12-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* | cifs: extra sanity checking for cifs.idmap keysJeff Layton2012-12-081-2/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | cifs: avoid extra allocation for small cifs.idmap keysJeff Layton2012-12-081-4/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | cifs: simplify id_to_sid and sid_to_id mapping codeJeff Layton2012-12-081-441/+94
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
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