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2009-04-18Smack: check for SMACK xattr validity in smack_inode_setxattrEtienne Basset
the following patch moves checks for SMACK xattr validity from smack_inode_post_setxattr (which cannot return an error to the user) to smack_inode_setxattr (which can return an error). Signed-off-by: Etienne Basset <etienne.basset@numericable.fr> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-03-28smack: Add a new '-CIPSO' option to the network address label configurationEtienne Basset
This patch adds a new special option '-CIPSO' to the Smack subsystem. When used in the netlabel list, it means "use CIPSO networking". A use case is when your local network speaks CIPSO and you want also to connect to the unlabeled Internet. This patch also add some documentation describing that. The patch also corrects an oops when setting a '' SMACK64 xattr to a file. Signed-off-by: Etienne Basset <etienne.basset@numericable.fr> Signed-off-by: Paul Moore <paul.moore@hp.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-03-28netlabel: Cleanup the Smack/NetLabel code to fix incoming TCP connectionsPaul Moore
This patch cleans up a lot of the Smack network access control code. The largest changes are to fix the labeling of incoming TCP connections in a manner similar to the recent SELinux changes which use the security_inet_conn_request() hook to label the request_sock and let the label move to the child socket via the normal network stack mechanisms. In addition to the incoming TCP connection fixes this patch also removes the smk_labled field from the socket_smack struct as the minor optimization advantage was outweighed by the difficulty in maintaining it's proper state. Signed-off-by: Paul Moore <paul.moore@hp.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-03-28netlabel: Label incoming TCP connections correctly in SELinuxPaul Moore
The current NetLabel/SELinux behavior for incoming TCP connections works but only through a series of happy coincidences that rely on the limited nature of standard CIPSO (only able to convey MLS attributes) and the write equality imposed by the SELinux MLS constraints. The problem is that network sockets created as the result of an incoming TCP connection were not on-the-wire labeled based on the security attributes of the parent socket but rather based on the wire label of the remote peer. The issue had to do with how IP options were managed as part of the network stack and where the LSM hooks were in relation to the code which set the IP options on these newly created child sockets. While NetLabel/SELinux did correctly set the socket's on-the-wire label it was promptly cleared by the network stack and reset based on the IP options of the remote peer. This patch, in conjunction with a prior patch that adjusted the LSM hook locations, works to set the correct on-the-wire label format for new incoming connections through the security_inet_conn_request() hook. Besides the correct behavior there are many advantages to this change, the most significant is that all of the NetLabel socket labeling code in SELinux now lives in hooks which can return error codes to the core stack which allows us to finally get ride of the selinux_netlbl_inode_permission() logic which greatly simplfies the NetLabel/SELinux glue code. In the process of developing this patch I also ran into a small handful of AF_INET6 cleanliness issues that have been fixed which should make the code safer and easier to extend in the future. Signed-off-by: Paul Moore <paul.moore@hp.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-03-26smack: convert smack to standard linux listsEtienne Basset
the following patch (on top of 2.6.29) converts Smack lists to standard linux lists Please review and consider for inclusion in 2.6.30-rc regards, Etienne Signed-off-by: Etienne Basset <etienne.basset@numericable.fr> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2009-03-24Merge branch 'master' into nextJames Morris
2009-03-05smack: fixes for unlabeled host supportetienne
The following patch (against 2.6.29rc5) fixes a few issues in the smack/netlabel "unlabeled host support" functionnality that was added in 2.6.29rc. It should go in before -final. 1) smack_host_label disregard a "0.0.0.0/0 @" rule (or other label), preventing 'tagged' tasks to access Internet (many systems drop packets with IP options) 2) netmasks were not handled correctly, they were stored in a way _not equivalent_ to conversion to be32 (it was equivalent for /0, /8, /16, /24, /32 masks but not other masks) 3) smack_netlbladdr prefixes (IP/mask) were not consistent (mask&IP was not done), so there could have been different list entries for the same IP prefix; if those entries had different labels, well ... 4) they were not sorted 1) 2) 3) are bugs, 4) is a more cosmetic issue. The patch : -creates a new helper smk_netlbladdr_insert to insert a smk_netlbladdr, -sorted by netmask length -use the new sorted nature of smack_netlbladdrs list to simplify smack_host_label : the first match _will_ be the more specific -corrects endianness issues in smk_write_netlbladdr & netlbladdr_seq_show Signed-off-by: <etienne.basset@numericable.fr> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-03-05smack: fixes for unlabeled host supportetienne
The following patch (against 2.6.29rc5) fixes a few issues in the smack/netlabel "unlabeled host support" functionnality that was added in 2.6.29rc. It should go in before -final. 1) smack_host_label disregard a "0.0.0.0/0 @" rule (or other label), preventing 'tagged' tasks to access Internet (many systems drop packets with IP options) 2) netmasks were not handled correctly, they were stored in a way _not equivalent_ to conversion to be32 (it was equivalent for /0, /8, /16, /24, /32 masks but not other masks) 3) smack_netlbladdr prefixes (IP/mask) were not consistent (mask&IP was not done), so there could have been different list entries for the same IP prefix; if those entries had different labels, well ... 4) they were not sorted 1) 2) 3) are bugs, 4) is a more cosmetic issue. The patch : -creates a new helper smk_netlbladdr_insert to insert a smk_netlbladdr, -sorted by netmask length -use the new sorted nature of smack_netlbladdrs list to simplify smack_host_label : the first match _will_ be the more specific -corrects endianness issues in smk_write_netlbladdr & netlbladdr_seq_show Signed-off-by: <etienne.basset@numericable.fr> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-19smack: fix lots of kernel-doc notationRandy Dunlap
Fix/add kernel-doc notation and fix typos in security/smack/. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-27smackfs load append mode fixCasey Schaufler
Given just how hard it is to find the code that uses MAY_APPEND it's probably not a big surprise that this went unnoticed for so long. The Smack rules loading code is incorrectly setting the MAY_READ bit when MAY_APPEND is requested. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08remove lots of double-semicolonsFernando Carrijo
Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Theodore Ts'o <tytso@mit.edu> Acked-by: Mark Fasheh <mfasheh@suse.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-07Merge branch 'next' into for-linusJames Morris
2009-01-07Revert "CRED: Fix regression in cap_capable() as shown up by sys_faccessat() ↵James Morris
[ver #2]" This reverts commit 14eaddc967b16017d4a1a24d2be6c28ecbe06ed8. David has a better version to come.
2009-01-05CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #2]David Howells
Fix a regression in cap_capable() due to: commit 5ff7711e635b32f0a1e558227d030c7e45b4a465 Author: David Howells <dhowells@redhat.com> Date: Wed Dec 31 02:52:28 2008 +0000 CRED: Differentiate objective and effective subjective credentials on a task The problem is that the above patch allows a process to have two sets of credentials, and for the most part uses the subjective credentials when accessing current's creds. There is, however, one exception: cap_capable(), and thus capable(), uses the real/objective credentials of the target task, whether or not it is the current task. Ordinarily this doesn't matter, since usually the two cred pointers in current point to the same set of creds. However, sys_faccessat() makes use of this facility to override the credentials of the calling process to make its test, without affecting the creds as seen from other processes. One of the things sys_faccessat() does is to make an adjustment to the effective capabilities mask, which cap_capable(), as it stands, then ignores. The affected capability check is in generic_permission(): if (!(mask & MAY_EXEC) || execute_ok(inode)) if (capable(CAP_DAC_OVERRIDE)) return 0; This change splits capable() from has_capability() down into the commoncap and SELinux code. The capable() security op now only deals with the current process, and uses the current process's subjective creds. A new security op - task_capable() - is introduced that can check any task's objective creds. strictly the capable() security op is superfluous with the presence of the task_capable() op, however it should be faster to call the capable() op since two fewer arguments need be passed down through the various layers. This can be tested by compiling the following program from the XFS testsuite: /* * t_access_root.c - trivial test program to show permission bug. * * Written by Michael Kerrisk - copyright ownership not pursued. * Sourced from: http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-10/6030.html */ #include <limits.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <sys/stat.h> #define UID 500 #define GID 100 #define PERM 0 #define TESTPATH "/tmp/t_access" static void errExit(char *msg) { perror(msg); exit(EXIT_FAILURE); } /* errExit */ static void accessTest(char *file, int mask, char *mstr) { printf("access(%s, %s) returns %d\n", file, mstr, access(file, mask)); } /* accessTest */ int main(int argc, char *argv[]) { int fd, perm, uid, gid; char *testpath; char cmd[PATH_MAX + 20]; testpath = (argc > 1) ? argv[1] : TESTPATH; perm = (argc > 2) ? strtoul(argv[2], NULL, 8) : PERM; uid = (argc > 3) ? atoi(argv[3]) : UID; gid = (argc > 4) ? atoi(argv[4]) : GID; unlink(testpath); fd = open(testpath, O_RDWR | O_CREAT, 0); if (fd == -1) errExit("open"); if (fchown(fd, uid, gid) == -1) errExit("fchown"); if (fchmod(fd, perm) == -1) errExit("fchmod"); close(fd); snprintf(cmd, sizeof(cmd), "ls -l %s", testpath); system(cmd); if (seteuid(uid) == -1) errExit("seteuid"); accessTest(testpath, 0, "0"); accessTest(testpath, R_OK, "R_OK"); accessTest(testpath, W_OK, "W_OK"); accessTest(testpath, X_OK, "X_OK"); accessTest(testpath, R_OK | W_OK, "R_OK | W_OK"); accessTest(testpath, R_OK | X_OK, "R_OK | X_OK"); accessTest(testpath, W_OK | X_OK, "W_OK | X_OK"); accessTest(testpath, R_OK | W_OK | X_OK, "R_OK | W_OK | X_OK"); exit(EXIT_SUCCESS); } /* main */ This can be run against an Ext3 filesystem as well as against an XFS filesystem. If successful, it will show: [root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043 ---------- 1 dhowells dhowells 0 2008-12-31 03:00 /tmp/xxx access(/tmp/xxx, 0) returns 0 access(/tmp/xxx, R_OK) returns 0 access(/tmp/xxx, W_OK) returns 0 access(/tmp/xxx, X_OK) returns -1 access(/tmp/xxx, R_OK | W_OK) returns 0 access(/tmp/xxx, R_OK | X_OK) returns -1 access(/tmp/xxx, W_OK | X_OK) returns -1 access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1 If unsuccessful, it will show: [root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043 ---------- 1 dhowells dhowells 0 2008-12-31 02:56 /tmp/xxx access(/tmp/xxx, 0) returns 0 access(/tmp/xxx, R_OK) returns -1 access(/tmp/xxx, W_OK) returns -1 access(/tmp/xxx, X_OK) returns -1 access(/tmp/xxx, R_OK | W_OK) returns -1 access(/tmp/xxx, R_OK | X_OK) returns -1 access(/tmp/xxx, W_OK | X_OK) returns -1 access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1 I've also tested the fix with the SELinux and syscalls LTP testsuites. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-04audit: validate comparison operations, store them in sane formAl Viro
Don't store the field->op in the messy (and very inconvenient for e.g. audit_comparator()) form; translate to dense set of values and do full validation of userland-submitted value while we are at it. ->audit_init_rule() and ->audit_match_rule() get new values now; in-tree instances updated. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31smack: Add support for unlabeled network hosts and networksCasey Schaufler
Add support for unlabeled network hosts and networks. Relies heavily on Paul Moore's netlabel support. Creates a new entry in /smack called netlabel. Writes to /smack/netlabel take the form: A.B.C.D LABEL or A.B.C.D/N LABEL where A.B.C.D is a network address, N is an integer between 0-32, and LABEL is the Smack label to be used. If /N is omitted /32 is assumed. N designates the netmask for the address. Entries are matched by the most specific address/mask pair. 0.0.0.0/0 will match everything, while 192.168.1.117/32 will match exactly one host. A new system label "@", pronounced "web", is defined. Processes can not be assigned the web label. An address assigned the web label can be written to by any process, and packets coming from a web address can be written to any socket. Use of the web label is a violation of any strict MAC policy, but the web label has been requested many times. The nltype entry has been removed from /smack. It did not work right and the netlabel interface can be used to specify that all hosts be treated as unlabeled. CIPSO labels on incoming packets will be honored, even from designated single label hosts. Single label hosts can only be written to by processes with labels that can write to the label of the host. Packets sent to single label hosts will always be unlabeled. Once added a single label designation cannot be removed, however the label may be changed. The behavior of the ambient label remains unchanged. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul.moore@hp.com>
2008-12-31netlabel: Update kernel configuration APIPaul Moore
Update the NetLabel kernel API to expose the new features added in kernel releases 2.6.25 and 2.6.28: the static/fallback label functionality and network address based selectors. Signed-off-by: Paul Moore <paul.moore@hp.com>
2008-12-25smackfs: check for allocation failures in smk_set_access()Sergio Luis
smackfs: check for allocation failures in smk_set_access() While adding a new subject/object pair to smack_list, smk_set_access() didn't check the return of kzalloc(). This patch changes smk_set_access() to return 0 or -ENOMEM, based on kzalloc()'s return. It also updates its caller, smk_write_load(), to check for smk_set_access()'s return, given it is no longer a void return function. Signed-off-by: Sergio Luis <sergio@larces.uece.br> To: Casey Schaufler <casey@schaufler-ca.com> Cc: Ahmed S. Darwish <darwish.07@gmail.com> Cc: LSM <linux-security-module@vger.kernel.org> Cc: LKLM <linux-kernel@vger.kernel.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2008-12-20security: pass mount flags to security_sb_kern_mount()James Morris
Pass mount flags to security_sb_kern_mount(), so security modules can determine if a mount operation is being performed by the kernel. Signed-off-by: James Morris <jmorris@namei.org> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
2008-11-14CRED: Allow kernel services to override LSM settings for task actionsDavid Howells
Allow kernel services to override LSM settings appropriate to the actions performed by a task by duplicating a set of credentials, modifying it and then using task_struct::cred to point to it when performing operations on behalf of a task. This is used, for example, by CacheFiles which has to transparently access the cache on behalf of a process that thinks it is doing, say, NFS accesses with a potentially inappropriate (with respect to accessing the cache) set of credentials. This patch provides two LSM hooks for modifying a task security record: (*) security_kernel_act_as() which allows modification of the security datum with which a task acts on other objects (most notably files). (*) security_kernel_create_files_as() which allows modification of the security datum that is used to initialise the security data on a file that a task creates. The patch also provides four new credentials handling functions, which wrap the LSM functions: (1) prepare_kernel_cred() Prepare a set of credentials for a kernel service to use, based either on a daemon's credentials or on init_cred. All the keyrings are cleared. (2) set_security_override() Set the LSM security ID in a set of credentials to a specific security context, assuming permission from the LSM policy. (3) set_security_override_from_ctx() As (2), but takes the security context as a string. (4) set_create_files_as() Set the file creation LSM security ID in a set of credentials to be the same as that on a particular inode. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> [Smack changes] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14CRED: Make execve() take advantage of copy-on-write credentialsDavid Howells
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 <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14CRED: Inaugurate COW credentialsDavid Howells
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>
2008-11-14CRED: Use RCU to access another task's creds and to release a task's own credsDavid Howells
Use RCU to access another task's creds and to release a task's own creds. This means that it will be possible for the credentials of a task to be replaced without another task (a) requiring a full lock to read them, and (b) seeing deallocated memory. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14CRED: Wrap current->cred and a few other accessorsDavid Howells
Wrap current->cred and a few other accessors to hide their actual implementation. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14CRED: Detach the credentials from task_structDavid Howells
Detach the credentials from task_struct, duplicating them in copy_process() and releasing them in __put_task_struct(). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14CRED: Separate task security context from task_structDavid Howells
Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-10-11Merge branch 'master' of ↵James Morris
git://git.infradead.org/users/pcmoore/lblnet-2.6_next into next
2008-10-10netlabel: Replace protocol/NetLabel linking with refrerence countsPaul Moore
NetLabel has always had a list of backpointers in the CIPSO DOI definition structure which pointed to the NetLabel LSM domain mapping structures which referenced the CIPSO DOI struct. The rationale for this was that when an administrator removed a CIPSO DOI from the system all of the associated NetLabel LSM domain mappings should be removed as well; a list of backpointers made this a simple operation. Unfortunately, while the backpointers did make the removal easier they were a bit of a mess from an implementation point of view which was making further development difficult. Since the removal of a CIPSO DOI is a realtively rare event it seems to make sense to remove this backpointer list as the optimization was hurting us more then it was helping. However, we still need to be able to track when a CIPSO DOI definition is being used so replace the backpointer list with a reference count. In order to preserve the current functionality of removing the associated LSM domain mappings when a CIPSO DOI is removed we walk the LSM domain mapping table, removing the relevant entries. Signed-off-by: Paul Moore <paul.moore@hp.com> Reviewed-by: James Morris <jmorris@namei.org>
2008-10-10smack: Fix missing calls to netlbl_skbuff_err()Paul Moore
Smack needs to call netlbl_skbuff_err() to let NetLabel do the necessary protocol specific error handling. Signed-off-by: Paul Moore <paul.moore@hp.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2008-08-28Merge branch 'master' into nextJames Morris
2008-08-14security: Fix setting of PF_SUPERPRIV by __capable()David Howells
Fix the setting of PF_SUPERPRIV by __capable() as it could corrupt the flags the target process if that is not the current process and it is trying to change its own flags in a different way at the same time. __capable() is using neither atomic ops nor locking to protect t->flags. This patch removes __capable() and introduces has_capability() that doesn't set PF_SUPERPRIV on the process being queried. This patch further splits security_ptrace() in two: (1) security_ptrace_may_access(). This passes judgement on whether one process may access another only (PTRACE_MODE_ATTACH for ptrace() and PTRACE_MODE_READ for /proc), and takes a pointer to the child process. current is the parent. (2) security_ptrace_traceme(). This passes judgement on PTRACE_TRACEME only, and takes only a pointer to the parent process. current is the child. In Smack and commoncap, this uses has_capability() to determine whether the parent will be permitted to use PTRACE_ATTACH if normal checks fail. This does not set PF_SUPERPRIV. Two of the instances of __capable() actually only act on current, and so have been changed to calls to capable(). Of the places that were using __capable(): (1) The OOM killer calls __capable() thrice when weighing the killability of a process. All of these now use has_capability(). (2) cap_ptrace() and smack_ptrace() were using __capable() to check to see whether the parent was allowed to trace any process. As mentioned above, these have been split. For PTRACE_ATTACH and /proc, capable() is now used, and for PTRACE_TRACEME, has_capability() is used. (3) cap_safe_nice() only ever saw current, so now uses capable(). (4) smack_setprocattr() rejected accesses to tasks other than current just after calling __capable(), so the order of these two tests have been switched and capable() is used instead. (5) In smack_file_send_sigiotask(), we need to allow privileged processes to receive SIGIO on files they're manipulating. (6) In smack_task_wait(), we let a process wait for a privileged process, whether or not the process doing the waiting is privileged. I've tested this with the LTP SELinux and syscalls testscripts. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Andrew G. Morgan <morgan@kernel.org> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: James Morris <jmorris@namei.org>
2008-08-05smack: limit privilege by labelCasey Schaufler
There have been a number of requests to make the Smack LSM enforce MAC even in the face of privilege, either capability based or superuser based. This is not universally desired, however, so it seems desirable to make it optional. Further, at least one legacy OS implemented a scheme whereby only processes running with one particular label could be exempt from MAC. This patch supports these three cases. If /smack/onlycap is empty (unset or null-string) privilege is enforced in the normal way. If /smack/onlycap contains a label only processes running with that label may be MAC exempt. If the label in /smack/onlycap is the star label ("*") the semantics of the star label combine with the privilege restrictions to prevent any violations of MAC, even in the presence of privilege. Again, this will be independent of the privilege scheme. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <jmorris@namei.org>
2008-07-26[PATCH] pass MAY_OPEN to vfs_permission() explicitlyAl Viro
... and get rid of the last "let's deduce mask from nameidata->flags" bit. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-14security: remove register_security hookJames Morris
The register security hook is no longer required, as the capability module is always registered. LSMs wishing to stack capability as a secondary module should do so explicitly. Signed-off-by: James Morris <jmorris@namei.org> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-14Security: split proc ptrace checking into read vs. attachStephen Smalley
Enable security modules to distinguish reading of process state via proc from full ptrace access by renaming ptrace_may_attach to ptrace_may_access and adding a mode argument indicating whether only read access or full attach access is requested. This allows security modules to permit access to reading process state without granting full ptrace access. The base DAC/capability checking remains unchanged. Read access to /proc/pid/mem continues to apply a full ptrace attach check since check_mem_permission() already requires the current task to already be ptracing the target. The other ptrace checks within proc for elements like environ, maps, and fds are changed to pass the read mode instead of attach. In the SELinux case, we model such reading of process state as a reading of a proc file labeled with the target process' label. This enables SELinux policy to permit such reading of process state without permitting control or manipulation of the target process, as there are a number of cases where programs probe for such information via proc but do not need to be able to control the target (e.g. procps, lsof, PolicyKit, ConsoleKit). At present we have to choose between allowing full ptrace in policy (more permissive than required/desired) or breaking functionality (or in some cases just silencing the denials via dontaudit rules but this can hide genuine attacks). This version of the patch incorporates comments from Casey Schaufler (change/replace existing ptrace_may_attach interface, pass access mode), and Chris Wright (provide greater consistency in the checking). Note that like their predecessors __ptrace_may_attach and ptrace_may_attach, the __ptrace_may_access and ptrace_may_access interfaces use different return value conventions from each other (0 or -errno vs. 1 or 0). I retained this difference to avoid any changes to the caller logic but made the difference clearer by changing the latter interface to return a bool rather than an int and by adding a comment about it to ptrace.h for any future callers. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: James Morris <jmorris@namei.org>
2008-06-04Smack: fuse mount hang fixCasey Schaufler
The d_instantiate hook for Smack can hang on the root inode of a filesystem if the file system code has not really done all the set-up. Fuse is known to encounter this problem. This change detects an attempt to instantiate a root inode and addresses it early in the processing, before any attempt is made to do something that might hang. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Tested-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30signals: cleanup security_task_kill() usage/implementationOleg Nesterov
Every implementation of ->task_kill() does nothing when the signal comes from the kernel. This is correct, but means that check_kill_permission() should call security_task_kill() only for SI_FROMUSER() case, and we can remove the same check from ->task_kill() implementations. (sadly, check_kill_permission() is the last user of signal->session/__session but we can't s/task_session_nr/task_session/ here). NOTE: Eric W. Biederman pointed out cap_task_kill() should die, and I think he is very right. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Roland McGrath <roland@redhat.com> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: David Quigley <dpquigl@tycho.nsa.gov> Cc: Eric Paris <eparis@redhat.com> Cc: Harald Welte <laforge@gnumonks.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30Smack: Integrate Smack with AuditAhmed S. Darwish
Setup the new Audit hooks for Smack. SELinux Audit rule fields are recycled to avoid `auditd' userspace modifications. Currently only equality testing is supported on labels acting as a subject (AUDIT_SUBJ_USER) or as an object (AUDIT_OBJ_USER). Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2008-04-30Security: Make secctx_to_secid() take const secdataDavid Howells
Make secctx_to_secid() take constant secdata. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-04-29Merge branch 'audit.b50' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current * 'audit.b50' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: [PATCH] new predicate - AUDIT_FILETYPE [patch 2/2] Use find_task_by_vpid in audit code [patch 1/2] audit: let userspace fully control TTY input auditing [PATCH 2/2] audit: fix sparse shadowed variable warnings [PATCH 1/2] audit: move extern declarations to audit.h Audit: MAINTAINERS update Audit: increase the maximum length of the key field Audit: standardize string audit interfaces Audit: stop deadlock from signals under load Audit: save audit_backlog_limit audit messages in case auditd comes back Audit: collect sessionid in netlink messages Audit: end printk with newline
2008-04-29xattr: add missing consts to function argumentsDavid Howells
Add missing consts to xattr function arguments. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28smack: use cap_task_prctlSerge E. Hallyn
With the introduction of per-process securebits, the capabilities-related prctl callbacks were moved into cap_task_prctl(). Have smack use cap_task_prctl() so that PR_SET_KEEPCAPS is defined. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28smack: make smk_cipso_doi() and smk_unlbl_ambient()Casey Schaufler
The functions smk_cipso_doi and smk_unlbl_ambient are not used outside smackfs.c and should hence be static. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28smack: fix integer as NULL pointer warning in smack_lsm.cHarvey Harrison
security/smack/smack_lsm.c:1257:16: warning: Using plain integer as NULL pointer Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28Audit: collect sessionid in netlink messagesEric Paris
Previously I added sessionid output to all audit messages where it was available but we still didn't know the sessionid of the sender of netlink messages. This patch adds that information to netlink messages so we can audit who sent netlink messages. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-21[PATCH] switch a bunch of LSM hooks from nameidata to pathAl Viro
Namely, ones from namespace.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-18Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: security: fix up documentation for security_module_enable Security: Introduce security= boot parameter Audit: Final renamings and cleanup SELinux: use new audit hooks, remove redundant exports Audit: internally use the new LSM audit hooks LSM/Audit: Introduce generic Audit LSM hooks SELinux: remove redundant exports Netlink: Use generic LSM hook Audit: use new LSM hooks instead of SELinux exports SELinux: setup new inode/ipc getsecid hooks LSM: Introduce inode_getsecid and ipc_getsecid hooks
2008-04-19Security: Introduce security= boot parameterAhmed S. Darwish
Add the security= boot parameter. This is done to avoid LSM registration clashes in case of more than one bult-in module. User can choose a security module to enable at boot. If no security= boot parameter is specified, only the first LSM asking for registration will be loaded. An invalid security module name will be treated as if no module has been chosen. LSM modules must check now if they are allowed to register by calling security_module_enable(ops) first. Modify SELinux and SMACK to do so. Do not let SMACK register smackfs if it was not chosen on boot. Smackfs assumes that smack hooks are registered and the initial task security setup (swapper->security) is done. Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: James Morris <jmorris@namei.org>
2008-04-12NetLabel: Allow passing the LSM domain as a shared pointerPaul Moore
Smack doesn't have the need to create a private copy of the LSM "domain" when setting NetLabel security attributes like SELinux, however, the current NetLabel code requires a private copy of the LSM "domain". This patches fixes that by letting the LSM determine how it wants to pass the domain value. * NETLBL_SECATTR_DOMAIN_CPY The current behavior, NetLabel assumes that the domain value is a copy and frees it when done * NETLBL_SECATTR_DOMAIN New, Smack-friendly behavior, NetLabel assumes that the domain value is a reference to a string managed by the LSM and does not free it when done Signed-off-by: Paul Moore <paul.moore@hp.com> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-24smackfs: remove redundant lock, fix open(,O_RDWR)Ahmed S. Darwish
Older smackfs was parsing MAC rules by characters, thus a need of locking write sessions on open() was needed. This lock is no longer useful now since each rule is handled by a single write() call. This is also a bugfix since seq_open() was not called if an open() O_RDWR flag was given, leading to a seq_read() without an initialized seq_file, thus an Oops. Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Reported-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>