user/sven/linux.git/include/linux/key.h, branch v3.0.51

Merge branch 'docs-move' of git://git.kernel.org/pub/scm/linux/kernel/git/rdunlap/linux-docs

2011-05-27T17:25:02Z

* 'docs-move' of git://git.kernel.org/pub/scm/linux/kernel/git/rdunlap/linux-docs: Create Documentation/security/, move LSM-, credentials-, and keys-related files from Documentation/ to Documentation/security/, add Documentation/security/00-INDEX, and update all occurrences of Documentation/ to Documentation/security/.

Create Documentation/security/,

2011-05-19T22:59:38Z

move LSM-, credentials-, and keys-related files from Documentation/ to Documentation/security/, add Documentation/security/00-INDEX, and update all occurrences of Documentation/ to Documentation/security/.

KEYS: Improve /proc/keys

2011-03-17T00:59:32Z

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 Signed-off-by: James Morris

KEYS: Add a new keyctl op to reject a key with a specified error code

2011-03-08T00:17:18Z

Add a new keyctl op to reject a key with a specified error code. This works much the same as negating a key, and so keyctl_negate_key() is made a special case of keyctl_reject_key(). The difference is that keyctl_negate_key() selects ENOKEY as the error to be reported. Typically the key would be rejected with EKEYEXPIRED, EKEYREVOKED or EKEYREJECTED, but this is not mandatory. Signed-off-by: David Howells Signed-off-by: James Morris

KEYS: Add an RCU payload dereference macro

2011-03-08T00:17:11Z

Add an RCU payload dereference macro as this seems to be a common piece of code amongst key types that use RCU referenced payloads. Signed-off-by: David Howells Signed-off-by: Mimi Zohar Signed-off-by: James Morris

keys: __rcu annotations

2010-08-20T00:18:00Z

Signed-off-by: Arnd Bergmann Signed-off-by: Paul E. McKenney Acked-by: David Howells Reviewed-by: Josh Triplett

KEYS: Add a keyctl to install a process's session keyring on its parent [try #6]

2009-09-02T11:29:22Z

Add a keyctl to install a process's session keyring onto its parent. This replaces the parent's session keyring. Because the COW credential code does not permit one process to change another process's credentials directly, the change is deferred until userspace next starts executing again. Normally this will be after a wait*() syscall. To support this, three new security hooks have been provided: cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in the blank security creds and key_session_to_parent() - which asks the LSM if the process may replace its parent's session keyring. The replacement may only happen if the process has the same ownership details as its parent, and the process has LINK permission on the session keyring, and the session keyring is owned by the process, and the LSM permits it. Note that this requires alteration to each architecture's notify_resume path. This has been done for all arches barring blackfin, m68k* and xtensa, all of which need assembly alteration to support TIF_NOTIFY_RESUME. This allows the replacement to be performed at the point the parent process resumes userspace execution. This allows the userspace AFS pioctl emulation to fully emulate newpag() and the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to alter the parent process's PAG membership. However, since kAFS doesn't use PAGs per se, but rather dumps the keys into the session keyring, the session keyring of the parent must be replaced if, for example, VIOCSETTOK is passed the newpag flag. This can be tested with the following program: #include #include #include #define KEYCTL_SESSION_TO_PARENT 18 #define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0) int main(int argc, char **argv) { key_serial_t keyring, key; long ret; keyring = keyctl_join_session_keyring(argv[1]); OSERROR(keyring, "keyctl_join_session_keyring"); key = add_key("user", "a", "b", 1, keyring); OSERROR(key, "add_key"); ret = keyctl(KEYCTL_SESSION_TO_PARENT); OSERROR(ret, "KEYCTL_SESSION_TO_PARENT"); return 0; } Compiled and linked with -lkeyutils, you should see something like: [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 355907932 --alswrv 4043 -1 \_ keyring: _uid.4043 [dhowells@andromeda ~]$ /tmp/newpag [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 1055658746 --alswrv 4043 4043 \_ user: a [dhowells@andromeda ~]$ /tmp/newpag hello [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: hello 340417692 --alswrv 4043 4043 \_ user: a Where the test program creates a new session keyring, sticks a user key named 'a' into it and then installs it on its parent. Signed-off-by: David Howells Signed-off-by: James Morris

KEYS: Add garbage collection for dead, revoked and expired keys. [try #6]

2009-09-02T11:29:11Z

Add garbage collection for dead, revoked and expired keys. This involved erasing all links to such keys from keyrings that point to them. At that point, the key will be deleted in the normal manner. Keyrings from which garbage collection occurs are shrunk and their quota consumption reduced as appropriate. Dead keys (for which the key type has been removed) will be garbage collected immediately. Revoked and expired keys will hang around for a number of seconds, as set in /proc/sys/kernel/keys/gc_delay before being automatically removed. The default is 5 minutes. Signed-off-by: David Howells Signed-off-by: James Morris

kmemtrace, security: fix linux/key.h header file dependencies

2009-04-03T10:21:12Z

Impact: cleanup We want to remove percpu.h from rcupdate.h (for upcoming kmemtrace changes), but this is not possible currently without breaking the build because key.h has an implicit include file dependency on rwsem.h: CC [M] fs/cifs/cifs_spnego.o In file included from include/keys/user-type.h:15, from fs/cifs/cifs_spnego.c:24: include/linux/key.h:128: error: field ‘sem’ has incomplete type make[2]: *** [fs/cifs/cifs_spnego.o] Error 1 make[1]: *** [fs/cifs] Error 2 make: *** [fs] Error 2 Fix it by making the dependency explicit. Signed-off-by: Pekka Enberg Cc: Eduard - Gabriel Munteanu LKML-Reference: <1237884886.25315.39.camel@penberg-laptop> Signed-off-by: Ingo Molnar

CRED: Make execve() take advantage of copy-on-write credentials

2008-11-13T23:39:24Z

Make execve() take advantage of copy-on-write credentials, allowing it to set up the credentials in advance, and then commit the whole lot after the point of no return. This patch and the preceding patches have been tested with the LTP SELinux testsuite. This patch makes several logical sets of alteration: (1) execve(). The credential bits from struct linux_binprm are, for the most part, replaced with a single credentials pointer (bprm->cred). This means that all the creds can be calculated in advance and then applied at the point of no return with no possibility of failure. I would like to replace bprm->cap_effective with: cap_isclear(bprm->cap_effective) but this seems impossible due to special behaviour for processes of pid 1 (they always retain their parent's capability masks where normally they'd be changed - see cap_bprm_set_creds()). The following sequence of events now happens: (a) At the start of do_execve, the current task's cred_exec_mutex is locked to prevent PTRACE_ATTACH from obsoleting the calculation of creds that we make. (a) prepare_exec_creds() is then called to make a copy of the current task's credentials and prepare it. This copy is then assigned to bprm->cred. This renders security_bprm_alloc() and security_bprm_free() unnecessary, and so they've been removed. (b) The determination of unsafe execution is now performed immediately after (a) rather than later on in the code. The result is stored in bprm->unsafe for future reference. (c) prepare_binprm() is called, possibly multiple times. (i) This applies the result of set[ug]id binaries to the new creds attached to bprm->cred. Personality bit clearance is recorded, but now deferred on the basis that the exec procedure may yet fail. (ii) This then calls the new security_bprm_set_creds(). This should calculate the new LSM and capability credentials into *bprm->cred. This folds together security_bprm_set() and parts of security_bprm_apply_creds() (these two have been removed). Anything that might fail must be done at this point. (iii) bprm->cred_prepared is set to 1. bprm->cred_prepared is 0 on the first pass of the security calculations, and 1 on all subsequent passes. This allows SELinux in (ii) to base its calculations only on the initial script and not on the interpreter. (d) flush_old_exec() is called to commit the task to execution. This performs the following steps with regard to credentials: (i) Clear pdeath_signal and set dumpable on certain circumstances that may not be covered by commit_creds(). (ii) Clear any bits in current->personality that were deferred from (c.i). (e) install_exec_creds() [compute_creds() as was] is called to install the new credentials. This performs the following steps with regard to credentials: (i) Calls security_bprm_committing_creds() to apply any security requirements, such as flushing unauthorised files in SELinux, that must be done before the credentials are changed. This is made up of bits of security_bprm_apply_creds() and security_bprm_post_apply_creds(), both of which have been removed. This function is not allowed to fail; anything that might fail must have been done in (c.ii). (ii) Calls commit_creds() to apply the new credentials in a single assignment (more or less). Possibly pdeath_signal and dumpable should be part of struct creds. (iii) Unlocks the task's cred_replace_mutex, thus allowing PTRACE_ATTACH to take place. (iv) Clears The bprm->cred pointer as the credentials it was holding are now immutable. (v) Calls security_bprm_committed_creds() to apply any security alterations that must be done after the creds have been changed. SELinux uses this to flush signals and signal handlers. (f) If an error occurs before (d.i), bprm_free() will call abort_creds() to destroy the proposed new credentials and will then unlock cred_replace_mutex. No changes to the credentials will have been made. (2) LSM interface. A number of functions have been changed, added or removed: (*) security_bprm_alloc(), ->bprm_alloc_security() (*) security_bprm_free(), ->bprm_free_security() Removed in favour of preparing new credentials and modifying those. (*) security_bprm_apply_creds(), ->bprm_apply_creds() (*) security_bprm_post_apply_creds(), ->bprm_post_apply_creds() Removed; split between security_bprm_set_creds(), security_bprm_committing_creds() and security_bprm_committed_creds(). (*) security_bprm_set(), ->bprm_set_security() Removed; folded into security_bprm_set_creds(). (*) security_bprm_set_creds(), ->bprm_set_creds() New. The new credentials in bprm->creds should be checked and set up as appropriate. bprm->cred_prepared is 0 on the first call, 1 on the second and subsequent calls. (*) security_bprm_committing_creds(), ->bprm_committing_creds() (*) security_bprm_committed_creds(), ->bprm_committed_creds() New. Apply the security effects of the new credentials. This includes closing unauthorised files in SELinux. This function may not fail. When the former is called, the creds haven't yet been applied to the process; when the latter is called, they have. The former may access bprm->cred, the latter may not. (3) SELinux. SELinux has a number of changes, in addition to those to support the LSM interface changes mentioned above: (a) The bprm_security_struct struct has been removed in favour of using the credentials-under-construction approach. (c) flush_unauthorized_files() now takes a cred pointer and passes it on to inode_has_perm(), file_has_perm() and dentry_open(). Signed-off-by: David Howells Acked-by: James Morris Acked-by: Serge Hallyn Signed-off-by: James Morris