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* keys: Fix proc_keys_next to increase position indexVasily Averin2020-04-161-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If seq_file .next function does not change position index, read after some lseek can generate unexpected output: $ dd if=/proc/keys bs=1 # full usual output 0f6bfdf5 I--Q--- 2 perm 3f010000 1000 1000 user 4af2f79ab8848d0a: 740 1fb91b32 I--Q--- 3 perm 1f3f0000 1000 65534 keyring _uid.1000: 2 27589480 I--Q--- 1 perm 0b0b0000 0 0 user invocation_id: 16 2f33ab67 I--Q--- 152 perm 3f030000 0 0 keyring _ses: 2 33f1d8fa I--Q--- 4 perm 3f030000 1000 1000 keyring _ses: 1 3d427fda I--Q--- 2 perm 3f010000 1000 1000 user 69ec44aec7678e5a: 740 3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 521+0 records in 521+0 records out 521 bytes copied, 0,00123769 s, 421 kB/s But a read after lseek in middle of last line results in the partial last line and then a repeat of the final line: $ dd if=/proc/keys bs=500 skip=1 dd: /proc/keys: cannot skip to specified offset g _uid_ses.1000: 1 3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 0+1 records in 0+1 records out 97 bytes copied, 0,000135035 s, 718 kB/s and a read after lseek beyond end of file results in the last line being shown: $ dd if=/proc/keys bs=1000 skip=1 # read after lseek beyond end of file dd: /proc/keys: cannot skip to specified offset 3ead4096 I--Q--- 1 perm 1f3f0000 1000 65534 keyring _uid_ses.1000: 1 0+1 records in 0+1 records out 76 bytes copied, 0,000119981 s, 633 kB/s See https://bugzilla.kernel.org/show_bug.cgi?id=206283 Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "Merge tag 'keys-acl-20190703' of ↵Linus Torvalds2019-07-101-13/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge tag 'keys-acl-20190703' of ↵Linus Torvalds2019-07-081-9/+13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull keyring ACL support from David Howells: "This changes the permissions model used by keys and keyrings to be based on an internal ACL by the following means: - Replace the permissions mask internally with an ACL that contains a list of ACEs, each with a specific subject with a permissions mask. Potted default ACLs are available for new keys and keyrings. ACE subjects can be macroised to indicate the UID and GID specified on the key (which remain). Future commits will be able to add additional subject types, such as specific UIDs or domain tags/namespaces. Also split a number of permissions to give finer control. Examples include splitting the revocation permit from the change-attributes permit, thereby allowing someone to be granted permission to revoke a key without allowing them to change the owner; also the ability to join a keyring is split from the ability to link to it, thereby stopping a process accessing a keyring by joining it and thus acquiring use of possessor permits. - Provide a keyctl to allow the granting or denial of one or more permits to a specific subject. Direct access to the ACL is not granted, and the ACL cannot be viewed" * tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: keys: Provide KEYCTL_GRANT_PERMISSION keys: Replace uid/gid/perm permissions checking with an ACL
| * keys: Replace uid/gid/perm permissions checking with an ACLDavid Howells2019-06-271-9/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge tag 'keys-namespace-20190627' of ↵Linus Torvalds2019-07-081-1/+2
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull keyring namespacing from David Howells: "These patches help make keys and keyrings more namespace aware. Firstly some miscellaneous patches to make the process easier: - Simplify key index_key handling so that the word-sized chunks assoc_array requires don't have to be shifted about, making it easier to add more bits into the key. - Cache the hash value in the key so that we don't have to calculate on every key we examine during a search (it involves a bunch of multiplications). - Allow keying_search() to search non-recursively. Then the main patches: - Make it so that keyring names are per-user_namespace from the point of view of KEYCTL_JOIN_SESSION_KEYRING so that they're not accessible cross-user_namespace. keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEYRING_NAME for this. - Move the user and user-session keyrings to the user_namespace rather than the user_struct. This prevents them propagating directly across user_namespaces boundaries (ie. the KEY_SPEC_* flags will only pick from the current user_namespace). - Make it possible to include the target namespace in which the key shall operate in the index_key. This will allow the possibility of multiple keys with the same description, but different target domains to be held in the same keyring. keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEY_TAG for this. - Make it so that keys are implicitly invalidated by removal of a domain tag, causing them to be garbage collected. - Institute a network namespace domain tag that allows keys to be differentiated by the network namespace in which they operate. New keys that are of a type marked 'KEY_TYPE_NET_DOMAIN' are assigned the network domain in force when they are created. - Make it so that the desired network namespace can be handed down into the request_key() mechanism. This allows AFS, NFS, etc. to request keys specific to the network namespace of the superblock. This also means that the keys in the DNS record cache are thenceforth namespaced, provided network filesystems pass the appropriate network namespace down into dns_query(). For DNS, AFS and NFS are good, whilst CIFS and Ceph are not. Other cache keyrings, such as idmapper keyrings, also need to set the domain tag - for which they need access to the network namespace of the superblock" * tag 'keys-namespace-20190627' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: keys: Pass the network namespace into request_key mechanism keys: Network namespace domain tag keys: Garbage collect keys for which the domain has been removed keys: Include target namespace in match criteria keys: Move the user and user-session keyrings to the user_namespace keys: Namespace keyring names keys: Add a 'recurse' flag for keyring searches keys: Cache the hash value to avoid lots of recalculation keys: Simplify key description management
| * keys: Add a 'recurse' flag for keyring searchesDavid Howells2019-06-261-1/+2
| | | | | | | | | | | | | | | | Add a 'recurse' flag for keyring searches so that the flag can be omitted and recursion disabled, thereby allowing just the nominated keyring to be searched and none of the children. Signed-off-by: David Howells <dhowells@redhat.com>
* | Merge tag 'keys-request-20190626' of ↵Linus Torvalds2019-07-081-1/+3
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull request_key improvements from David Howells: "These are all request_key()-related, including a fix and some improvements: - Fix the lack of a Link permission check on a key found by request_key(), thereby enabling request_key() to link keys that don't grant this permission to the target keyring (which must still grant Write permission). Note that the key must be in the caller's keyrings already to be found. - Invalidate used request_key authentication keys rather than revoking them, so that they get cleaned up immediately rather than hanging around till the expiry time is passed. - Move the RCU locks outwards from the keyring search functions so that a request_key_rcu() can be provided. This can be called in RCU mode, so it can't sleep and can't upcall - but it can be called from LOOKUP_RCU pathwalk mode. - Cache the latest positive result of request_key*() temporarily in task_struct so that filesystems that make a lot of request_key() calls during pathwalk can take advantage of it to avoid having to redo the searching. This requires CONFIG_KEYS_REQUEST_CACHE=y. It is assumed that the key just found is likely to be used multiple times in each step in an RCU pathwalk, and is likely to be reused for the next step too. Note that the cleanup of the cache is done on TIF_NOTIFY_RESUME, just before userspace resumes, and on exit" * tag 'keys-request-20190626' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: keys: Kill off request_key_async{,_with_auxdata} keys: Cache result of request_key*() temporarily in task_struct keys: Provide request_key_rcu() keys: Move the RCU locks outwards from the keyring search functions keys: Invalidate used request_key authentication keys keys: Fix request_key() lack of Link perm check on found key
| * keys: Move the RCU locks outwards from the keyring search functionsDavid Howells2019-06-191-1/+3
| | | | | | | | | | | | | | | | Move the RCU locks outwards from the keyring search functions so that it will become possible to provide an RCU-capable partial request_key() function in a later commit. Signed-off-by: David Howells <dhowells@redhat.com>
* | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner2019-05-301-5/+1
|/ | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KEYS: always initialize keyring_index_key::desc_lenEric Biggers2019-02-221-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot hit the 'BUG_ON(index_key->desc_len == 0);' in __key_link_begin() called from construct_alloc_key() during sys_request_key(), because the length of the key description was never calculated. The problem is that we rely on ->desc_len being initialized by search_process_keyrings(), specifically by search_nested_keyrings(). But, if the process isn't subscribed to any keyrings that never happens. Fix it by always initializing keyring_index_key::desc_len as soon as the description is set, like we already do in some places. The following program reproduces the BUG_ON() when it's run as root and no session keyring has been installed. If it doesn't work, try removing pam_keyinit.so from /etc/pam.d/login and rebooting. #include <stdlib.h> #include <unistd.h> #include <keyutils.h> int main(void) { int id = add_key("keyring", "syz", NULL, 0, KEY_SPEC_USER_KEYRING); keyctl_setperm(id, KEY_OTH_WRITE); setreuid(5000, 5000); request_key("user", "desc", "", id); } Reported-by: syzbot+ec24e95ea483de0a24da@syzkaller.appspotmail.com Fixes: b2a4df200d57 ("KEYS: Expand the capacity of a keyring") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: James Morris <james.morris@microsoft.com>
* security: audit and remove any unnecessary uses of module.hPaul Gortmaker2018-12-121-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in removing such instances is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h might have been the implicit source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each instance for the presence of either and replace as needed. Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: John Johansen <john.johansen@canonical.com> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: linux-security-module@vger.kernel.org Cc: linux-integrity@vger.kernel.org Cc: keyrings@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: James Morris <james.morris@microsoft.com>
* proc: introduce proc_create_seq{,_data}Christoph Hellwig2018-05-161-32/+2
| | | | | | | | | Variants of proc_create{,_data} that directly take a struct seq_operations argument and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig <hch@lst.de>
* security: keys: Replace time_t/timespec with time64_tBaolin Wang2017-11-151-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | The 'struct key' will use 'time_t' which we try to remove in the kernel, since 'time_t' is not year 2038 safe on 32bit systems. Also the 'struct keyring_search_context' will use 'timespec' type to record current time, which is also not year 2038 safe on 32bit systems. Thus this patch replaces 'time_t' with 'time64_t' which is year 2038 safe for 'struct key', and replace 'timespec' with 'time64_t' for the 'struct keyring_search_context', since we only look at the the seconds part of 'timespec' variable. Moreover we also change the codes where using the 'time_t' and 'timespec', and we can get current time by ktime_get_real_seconds() instead of current_kernel_time(), and use 'TIME64_MAX' macro to initialize the 'time64_t' type variable. Especially in proc.c file, we have replaced 'unsigned long' and 'timespec' type with 'u64' and 'time64_t' type to save the timeout value, which means user will get one 'u64' type timeout value by issuing proc_keys_show() function. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com>
* KEYS: load key flags and expiry time atomically in proc_keys_show()Eric Biggers2017-10-181-10/+14
| | | | | | | | | In proc_keys_show(), the key semaphore is not held, so the key ->flags and ->expiry can be changed concurrently. We therefore should read them atomically just once. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
* KEYS: Fix race between updating and finding a negative keyDavid Howells2017-10-181-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Consolidate KEY_FLAG_INSTANTIATED, KEY_FLAG_NEGATIVE and the rejection error into one field such that: (1) The instantiation state can be modified/read atomically. (2) The error can be accessed atomically with the state. (3) The error isn't stored unioned with the payload pointers. This deals with the problem that the state is spread over three different objects (two bits and a separate variable) and reading or updating them atomically isn't practical, given that not only can uninstantiated keys change into instantiated or rejected keys, but rejected keys can also turn into instantiated keys - and someone accessing the key might not be using any locking. The main side effect of this problem is that what was held in the payload may change, depending on the state. For instance, you might observe the key to be in the rejected state. You then read the cached error, but if the key semaphore wasn't locked, the key might've become instantiated between the two reads - and you might now have something in hand that isn't actually an error code. The state is now KEY_IS_UNINSTANTIATED, KEY_IS_POSITIVE or a negative error code if the key is negatively instantiated. The key_is_instantiated() function is replaced with key_is_positive() to avoid confusion as negative keys are also 'instantiated'. Additionally, barriering is included: (1) Order payload-set before state-set during instantiation. (2) Order state-read before payload-read when using the key. Further separate barriering is necessary if RCU is being used to access the payload content after reading the payload pointers. Fixes: 146aa8b1453b ("KEYS: Merge the type-specific data with the payload data") Cc: stable@vger.kernel.org # v4.4+ Reported-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Eric Biggers <ebiggers@google.com>
* KEYS: restrict /proc/keys by credentials at open timeEric Biggers2017-09-251-6/+2
| | | | | | | | | | | | | | When checking for permission to view keys whilst reading from /proc/keys, we should use the credentials with which the /proc/keys file was opened. This is because, in a classic type of exploit, it can be possible to bypass checks for the *current* credentials by passing the file descriptor to a suid program. Following commit 34dbbcdbf633 ("Make file credentials available to the seqfile interfaces") we can finally fix it. So let's do it. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
* security, keys: convert key_user.usage from atomic_t to refcount_tElena Reshetova2017-04-031-1/+1
| | | | | | | | | | | | | | | refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
* security, keys: convert key.usage from atomic_t to refcount_tElena Reshetova2017-04-031-1/+1
| | | | | | | | | | | | | | | refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
* KEYS: Fix short sprintf buffer in /proc/keys show functionDavid Howells2016-10-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes CVE-2016-7042. Fix a short sprintf buffer in proc_keys_show(). If the gcc stack protector is turned on, this can cause a panic due to stack corruption. The problem is that xbuf[] is not big enough to hold a 64-bit timeout rendered as weeks: (gdb) p 0xffffffffffffffffULL/(60*60*24*7) $2 = 30500568904943 That's 14 chars plus NUL, not 11 chars plus NUL. Expand the buffer to 16 chars. I think the unpatched code apparently works if the stack-protector is not enabled because on a 32-bit machine the buffer won't be overflowed and on a 64-bit machine there's a 64-bit aligned pointer at one side and an int that isn't checked again on the other side. The panic incurred looks something like: Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff81352ebe CPU: 0 PID: 1692 Comm: reproducer Not tainted 4.7.2-201.fc24.x86_64 #1 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 0000000000000086 00000000fbbd2679 ffff8800a044bc00 ffffffff813d941f ffffffff81a28d58 ffff8800a044bc98 ffff8800a044bc88 ffffffff811b2cb6 ffff880000000010 ffff8800a044bc98 ffff8800a044bc30 00000000fbbd2679 Call Trace: [<ffffffff813d941f>] dump_stack+0x63/0x84 [<ffffffff811b2cb6>] panic+0xde/0x22a [<ffffffff81352ebe>] ? proc_keys_show+0x3ce/0x3d0 [<ffffffff8109f7f9>] __stack_chk_fail+0x19/0x30 [<ffffffff81352ebe>] proc_keys_show+0x3ce/0x3d0 [<ffffffff81350410>] ? key_validate+0x50/0x50 [<ffffffff8134db30>] ? key_default_cmp+0x20/0x20 [<ffffffff8126b31c>] seq_read+0x2cc/0x390 [<ffffffff812b6b12>] proc_reg_read+0x42/0x70 [<ffffffff81244fc7>] __vfs_read+0x37/0x150 [<ffffffff81357020>] ? security_file_permission+0xa0/0xc0 [<ffffffff81246156>] vfs_read+0x96/0x130 [<ffffffff81247635>] SyS_read+0x55/0xc0 [<ffffffff817eb872>] entry_SYSCALL_64_fastpath+0x1a/0xa4 Reported-by: Ondrej Kozina <okozina@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Ondrej Kozina <okozina@redhat.com> cc: stable@vger.kernel.org Signed-off-by: James Morris <james.l.morris@oracle.com>
* KEYS: Make /proc/keys unconditional if CONFIG_KEYS=yDavid Howells2015-01-221-8/+0
| | | | | | | | | | Now that /proc/keys is used by libkeyutils to look up a key by type and description, we should make it unconditional and remove CONFIG_DEBUG_PROC_KEYS. Reported-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Jiri Kosina <jkosina@suse.cz>
* KEYS: Preparse match dataDavid Howells2014-09-161-4/+4
| | | | | | | | | | | | | | | | | Preparse the match data. This provides several advantages: (1) The preparser can reject invalid criteria up front. (2) The preparser can convert the criteria to binary data if necessary (the asymmetric key type really wants to do binary comparison of the key IDs). (3) The preparser can set the type of search to be performed. This means that it's not then a one-off setting in the key type. (4) The preparser can set an appropriate comparator function. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com>
* KEYS: Move the flags representing required permission to linux/key.hDavid Howells2014-03-141-1/+1
| | | | | | | | | | | | | | | | | | Move the flags representing required permission to linux/key.h as the perm parameter of security_key_permission() is in terms of them - and not the permissions mask flags used in key->perm. Whilst we're at it: (1) Rename them to be KEY_NEED_xxx rather than KEY_xxx to avoid collisions with symbols in uapi/linux/input.h. (2) Don't use key_perm_t for a mask of required permissions, but rather limit it to the permissions mask attached to the key and arguments related directly to that. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
* KEYS: Introduce a search context structureDavid Howells2013-09-241-5/+12
| | | | | | | | | | | | | | | | | | | Search functions pass around a bunch of arguments, each of which gets copied with each call. Introduce a search context structure to hold these. Whilst we're at it, create a search flag that indicates whether the search should be directly to the description or whether it should iterate through all keys looking for a non-description match. This will be useful when keyrings use a generic data struct with generic routines to manage their content as the search terms can just be passed through to the iterator callback function. Also, for future use, the data to be supplied to the match function is separated from the description pointer in the search context. This makes it clear which is being supplied. Signed-off-by: David Howells <dhowells@redhat.com>
* userns: Convert security/keys to the new userns infrastructureEric W. Biederman2012-09-131-22/+22
| | | | | | | | | | | | | - Replace key_user ->user_ns equality checks with kuid_has_mapping checks. - Use from_kuid to generate key descriptions - Use kuid_t and kgid_t and the associated helpers instead of uid_t and gid_t - Avoid potential problems with file descriptor passing by displaying keys in the user namespace of the opener of key status proc files. Cc: linux-security-module@vger.kernel.org Cc: keyrings@linux-nfs.org Cc: David Howells <dhowells@redhat.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* KEYS: Add invalidation supportDavid Howells2012-05-111-1/+2
| | | | | | | | | | | | | | | | | | | Add support for invalidating a key - which renders it immediately invisible to further searches and causes the garbage collector to immediately wake up, remove it from keyrings and then destroy it when it's no longer referenced. It's better not to do this with keyctl_revoke() as that marks the key to start returning -EKEYREVOKED to searches when what is actually desired is to have the key refetched. To invalidate a key the caller must be granted SEARCH permission by the key. This may be too strict. It may be better to also permit invalidation if the caller has any of READ, WRITE or SETATTR permission. The primary use for this is to evict keys that are cached in special keyrings, such as the DNS resolver or an ID mapper. Signed-off-by: David Howells <dhowells@redhat.com>
* KEYS: Improve /proc/keysDavid Howells2011-03-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Improve /proc/keys by: (1) Don't attempt to summarise the payload of a negated key. It won't have one. To this end, a helper function - key_is_instantiated() has been added that allows the caller to find out whether the key is positively instantiated (as opposed to being uninstantiated or negatively instantiated). (2) Do show keys that are negative, expired or revoked rather than hiding them. This requires an override flag (no_state_check) to be passed to search_my_process_keyrings() and keyring_search_aux() to suppress this check. Without this, keys that are possessed by the caller, but only grant permissions to the caller if possessed are skipped as the possession check fails. Keys that are visible due to user, group or other checks are visible with or without this patch. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* KEYS: Fix up comments in key management codeDavid Howells2011-01-211-4/+6
| | | | | | | Fix up comments in the key management code. No functional changes. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* KEYS: Do some style cleanup in the key management code.David Howells2011-01-211-6/+1
| | | | | | | | | | | | | | | | | | Do a bit of a style clean up in the key management code. No functional changes. Done using: perl -p -i -e 's!^/[*]*/\n!!' security/keys/*.c perl -p -i -e 's!} /[*] end [a-z0-9_]*[(][)] [*]/\n!}\n!' security/keys/*.c sed -i -s -e ": next" -e N -e 's/^\n[}]$/}/' -e t -e P -e 's/^.*\n//' -e "b next" security/keys/*.c To remove /*****/ lines, remove comments on the closing brace of a function to name the function and remove blank lines before the closing brace of a function. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* KEYS: Make /proc/keys check to see if a key is possessed before security checkDavid Howells2010-08-021-2/+18
| | | | | | | | | | | | Make /proc/keys check to see if the calling process possesses each key before performing the security check. The possession check can be skipped if the key doesn't have the possessor-view permission bit set. This causes the keys a process possesses to show up in /proc/keys, even if they don't have matching user/group/other view permissions. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* Merge branch 'master' into nextJames Morris2010-05-061-1/+0
|\
| * include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* | security: whitespace coding style fixesJustin P. Mattock2010-04-231-1/+1
|/ | | | | | | Whitespace coding style fixes. Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: James Morris <jmorris@namei.org>
* KEYS: Do some whitespace cleanups [try #6]David Howells2009-09-021-9/+3
| | | | | | | | Do some whitespace cleanups in the key management code. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* KEYS: Make /proc/keys use keyid not numread as file position [try #6]Serge E. Hallyn2009-09-021-22/+55
| | | | | | | | | | | Make the file position maintained by /proc/keys represent the ID of the key just read rather than the number of keys read. This should make it faster to perform a lookup as we don't have to scan the key ID tree from the beginning to find the current position. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* keys: annotate seqfile ops with __releases and __acquiresJames Morris2009-06-251-0/+4
| | | | | | | | Annotate seqfile ops with __releases and __acquires to stop sparse complaining about unbalanced locking. Signed-off-by: James Morris <jmorris@namei.org> Reviewed-by: Serge Hallyn <serue@us.ibm.com>
* keys: make procfiles per-user-namespaceSerge E. Hallyn2009-02-271-6/+49
| | | | | | | | | | | | | | Restrict the /proc/keys and /proc/key-users output to keys belonging to the same user namespace as the reading task. We may want to make this more complicated - so that any keys in a user-namespace which is belongs to the reading task are also shown. But let's see if anyone wants that first. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* CRED: Inaugurate COW credentialsDavid Howells2008-11-141-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Inaugurate copy-on-write credentials management. This uses RCU to manage the credentials pointer in the task_struct with respect to accesses by other tasks. A process may only modify its own credentials, and so does not need locking to access or modify its own credentials. A mutex (cred_replace_mutex) is added to the task_struct to control the effect of PTRACE_ATTACHED on credential calculations, particularly with respect to execve(). With this patch, the contents of an active credentials struct may not be changed directly; rather a new set of credentials must be prepared, modified and committed using something like the following sequence of events: struct cred *new = prepare_creds(); int ret = blah(new); if (ret < 0) { abort_creds(new); return ret; } return commit_creds(new); There are some exceptions to this rule: the keyrings pointed to by the active credentials may be instantiated - keyrings violate the COW rule as managing COW keyrings is tricky, given that it is possible for a task to directly alter the keys in a keyring in use by another task. To help enforce this, various pointers to sets of credentials, such as those in the task_struct, are declared const. The purpose of this is compile-time discouragement of altering credentials through those pointers. Once a set of credentials has been made public through one of these pointers, it may not be modified, except under special circumstances: (1) Its reference count may incremented and decremented. (2) The keyrings to which it points may be modified, but not replaced. The only safe way to modify anything else is to create a replacement and commit using the functions described in Documentation/credentials.txt (which will be added by a later patch). This patch and the preceding patches have been tested with the LTP SELinux testsuite. This patch makes several logical sets of alteration: (1) execve(). This now prepares and commits credentials in various places in the security code rather than altering the current creds directly. (2) Temporary credential overrides. do_coredump() and sys_faccessat() now prepare their own credentials and temporarily override the ones currently on the acting thread, whilst preventing interference from other threads by holding cred_replace_mutex on the thread being dumped. This will be replaced in a future patch by something that hands down the credentials directly to the functions being called, rather than altering the task's objective credentials. (3) LSM interface. A number of functions have been changed, added or removed: (*) security_capset_check(), ->capset_check() (*) security_capset_set(), ->capset_set() Removed in favour of security_capset(). (*) security_capset(), ->capset() New. This is passed a pointer to the new creds, a pointer to the old creds and the proposed capability sets. It should fill in the new creds or return an error. All pointers, barring the pointer to the new creds, are now const. (*) security_bprm_apply_creds(), ->bprm_apply_creds() Changed; now returns a value, which will cause the process to be killed if it's an error. (*) security_task_alloc(), ->task_alloc_security() Removed in favour of security_prepare_creds(). (*) security_cred_free(), ->cred_free() New. Free security data attached to cred->security. (*) security_prepare_creds(), ->cred_prepare() New. Duplicate any security data attached to cred->security. (*) security_commit_creds(), ->cred_commit() New. Apply any security effects for the upcoming installation of new security by commit_creds(). (*) security_task_post_setuid(), ->task_post_setuid() Removed in favour of security_task_fix_setuid(). (*) security_task_fix_setuid(), ->task_fix_setuid() Fix up the proposed new credentials for setuid(). This is used by cap_set_fix_setuid() to implicitly adjust capabilities in line with setuid() changes. Changes are made to the new credentials, rather than the task itself as in security_task_post_setuid(). (*) security_task_reparent_to_init(), ->task_reparent_to_init() Removed. Instead the task being reparented to init is referred directly to init's credentials. NOTE! This results in the loss of some state: SELinux's osid no longer records the sid of the thread that forked it. (*) security_key_alloc(), ->key_alloc() (*) security_key_permission(), ->key_permission() Changed. These now take cred pointers rather than task pointers to refer to the security context. (4) sys_capset(). This has been simplified and uses less locking. The LSM functions it calls have been merged. (5) reparent_to_kthreadd(). This gives the current thread the same credentials as init by simply using commit_thread() to point that way. (6) __sigqueue_alloc() and switch_uid() __sigqueue_alloc() can't stop the target task from changing its creds beneath it, so this function gets a reference to the currently applicable user_struct which it then passes into the sigqueue struct it returns if successful. switch_uid() is now called from commit_creds(), and possibly should be folded into that. commit_creds() should take care of protecting __sigqueue_alloc(). (7) [sg]et[ug]id() and co and [sg]et_current_groups. The set functions now all use prepare_creds(), commit_creds() and abort_creds() to build and check a new set of credentials before applying it. security_task_set[ug]id() is called inside the prepared section. This guarantees that nothing else will affect the creds until we've finished. The calling of set_dumpable() has been moved into commit_creds(). Much of the functionality of set_user() has been moved into commit_creds(). The get functions all simply access the data directly. (8) security_task_prctl() and cap_task_prctl(). security_task_prctl() has been modified to return -ENOSYS if it doesn't want to handle a function, or otherwise return the return value directly rather than through an argument. Additionally, cap_task_prctl() now prepares a new set of credentials, even if it doesn't end up using it. (9) Keyrings. A number of changes have been made to the keyrings code: (a) switch_uid_keyring(), copy_keys(), exit_keys() and suid_keys() have all been dropped and built in to the credentials functions directly. They may want separating out again later. (b) key_alloc() and search_process_keyrings() now take a cred pointer rather than a task pointer to specify the security context. (c) copy_creds() gives a new thread within the same thread group a new thread keyring if its parent had one, otherwise it discards the thread keyring. (d) The authorisation key now points directly to the credentials to extend the search into rather pointing to the task that carries them. (e) Installing thread, process or session keyrings causes a new set of credentials to be created, even though it's not strictly necessary for process or session keyrings (they're shared). (10) Usermode helper. The usermode helper code now carries a cred struct pointer in its subprocess_info struct instead of a new session keyring pointer. This set of credentials is derived from init_cred and installed on the new process after it has been cloned. call_usermodehelper_setup() allocates the new credentials and call_usermodehelper_freeinfo() discards them if they haven't been used. A special cred function (prepare_usermodeinfo_creds()) is provided specifically for call_usermodehelper_setup() to call. call_usermodehelper_setkeys() adjusts the credentials to sport the supplied keyring as the new session keyring. (11) SELinux. SELinux has a number of changes, in addition to those to support the LSM interface changes mentioned above: (a) selinux_setprocattr() no longer does its check for whether the current ptracer can access processes with the new SID inside the lock that covers getting the ptracer's SID. Whilst this lock ensures that the check is done with the ptracer pinned, the result is only valid until the lock is released, so there's no point doing it inside the lock. (12) is_single_threaded(). This function has been extracted from selinux_setprocattr() and put into a file of its own in the lib/ directory as join_session_keyring() now wants to use it too. The code in SELinux just checked to see whether a task shared mm_structs with other tasks (CLONE_VM), but that isn't good enough. We really want to know if they're part of the same thread group (CLONE_THREAD). (13) nfsd. The NFS server daemon now has to use the COW credentials to set the credentials it is going to use. It really needs to pass the credentials down to the functions it calls, but it can't do that until other patches in this series have been applied. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: James Morris <jmorris@namei.org>
* keys: make the keyring quotas controllable through /proc/sysDavid Howells2008-04-291-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the keyring quotas controllable through /proc/sys files: (*) /proc/sys/kernel/keys/root_maxkeys /proc/sys/kernel/keys/root_maxbytes Maximum number of keys that root may have and the maximum total number of bytes of data that root may have stored in those keys. (*) /proc/sys/kernel/keys/maxkeys /proc/sys/kernel/keys/maxbytes Maximum number of keys that each non-root user may have and the maximum total number of bytes of data that each of those users may have stored in their keys. Also increase the quotas as a number of people have been complaining that it's not big enough. I'm not sure that it's big enough now either, but on the other hand, it can now be set in /etc/sysctl.conf. Signed-off-by: David Howells <dhowells@redhat.com> Cc: <kwc@citi.umich.edu> Cc: <arunsr@cse.iitk.ac.in> Cc: <dwalsh@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* keys: switch to proc_create()Alexey Dobriyan2008-04-291-6/+2
| | | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* security/selinux: constify function pointer tables and fieldsJan Engelhardt2008-01-251-2/+2
| | | | | | | Constify function pointer tables and fields. Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de> Signed-off-by: James Morris <jmorris@namei.org>
* [PATCH] mark struct file_operations const 9Arjan van de Ven2007-02-121-2/+2
| | | | | | | | | | | Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] keys: restrict contents of /proc/keys to Viewable keysMichael LeMay2006-06-261-0/+7
| | | | | | | | | | | | | Restrict /proc/keys such that only those keys to which the current task is granted View permission are presented. The documentation is also updated to reflect these changes. Signed-off-by: Michael LeMay <mdlemay@epoch.ncsc.mil> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Keys: Add possessor permissions to keys [try #3]David Howells2005-09-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The attached patch adds extra permission grants to keys for the possessor of a key in addition to the owner, group and other permissions bits. This makes SUID binaries easier to support without going as far as labelling keys and key targets using the LSM facilities. This patch adds a second "pointer type" to key structures (struct key_ref *) that can have the bottom bit of the address set to indicate the possession of a key. This is propagated through searches from the keyring to the discovered key. It has been made a separate type so that the compiler can spot attempts to dereference a potentially incorrect pointer. The "possession" attribute can't be attached to a key structure directly as it's not an intrinsic property of a key. Pointers to keys have been replaced with struct key_ref *'s wherever possession information needs to be passed through. This does assume that the bottom bit of the pointer will always be zero on return from kmem_cache_alloc(). The key reference type has been made into a typedef so that at least it can be located in the sources, even though it's basically a pointer to an undefined type. I've also renamed the accessor functions to be more useful, and all reference variables should now end in "_ref". Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] keys: Discard key spinlock and use RCU for key payloadDavid Howells2005-06-241-8/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The attached patch changes the key implementation in a number of ways: (1) It removes the spinlock from the key structure. (2) The key flags are now accessed using atomic bitops instead of write-locking the key spinlock and using C bitwise operators. The three instantiation flags are dealt with with the construction semaphore held during the request_key/instantiate/negate sequence, thus rendering the spinlock superfluous. The key flags are also now bit numbers not bit masks. (3) The key payload is now accessed using RCU. This permits the recursive keyring search algorithm to be simplified greatly since no locks need be taken other than the usual RCU preemption disablement. Searching now does not require any locks or semaphores to be held; merely that the starting keyring be pinned. (4) The keyring payload now includes an RCU head so that it can be disposed of by call_rcu(). This requires that the payload be copied on unlink to prevent introducing races in copy-down vs search-up. (5) The user key payload is now a structure with the data following it. It includes an RCU head like the keyring payload and for the same reason. It also contains a data length because the data length in the key may be changed on another CPU whilst an RCU protected read is in progress on the payload. This would then see the supposed RCU payload and the on-key data length getting out of sync. I'm tempted to drop the key's datalen entirely, except that it's used in conjunction with quota management and so is a little tricky to get rid of. (6) Update the keys documentation. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+251
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!