06 Jan, 2009

3 commits

  • * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
    inotify: fix type errors in interfaces
    fix breakage in reiserfs_new_inode()
    fix the treatment of jfs special inodes
    vfs: remove duplicate code in get_fs_type()
    add a vfs_fsync helper
    sys_execve and sys_uselib do not call into fsnotify
    zero i_uid/i_gid on inode allocation
    inode->i_op is never NULL
    ntfs: don't NULL i_op
    isofs check for NULL ->i_op in root directory is dead code
    affs: do not zero ->i_op
    kill suid bit only for regular files
    vfs: lseek(fd, 0, SEEK_CUR) race condition

    Linus Torvalds
     
  • ... and don't bother in callers. Don't bother with zeroing i_blocks,
    while we are at it - it's already been zeroed.

    i_mode is not worth the effort; it has no common default value.

    Signed-off-by: Al Viro

    Al Viro
     
  • We used to have rather schizophrenic set of checks for NULL ->i_op even
    though it had been eliminated years ago. You'd need to go out of your
    way to set it to NULL explicitly _and_ a bunch of code would die on
    such inodes anyway. After killing two remaining places that still
    did that bogosity, all that crap can go away.

    Signed-off-by: Al Viro

    Al Viro
     

05 Jan, 2009

1 commit

  • 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

    Al Viro
     

04 Jan, 2009

1 commit

  • …/git/tip/linux-2.6-tip

    * 'cpus4096-for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (77 commits)
    x86: setup_per_cpu_areas() cleanup
    cpumask: fix compile error when CONFIG_NR_CPUS is not defined
    cpumask: use alloc_cpumask_var_node where appropriate
    cpumask: convert shared_cpu_map in acpi_processor* structs to cpumask_var_t
    x86: use cpumask_var_t in acpi/boot.c
    x86: cleanup some remaining usages of NR_CPUS where s/b nr_cpu_ids
    sched: put back some stack hog changes that were undone in kernel/sched.c
    x86: enable cpus display of kernel_max and offlined cpus
    ia64: cpumask fix for is_affinity_mask_valid()
    cpumask: convert RCU implementations, fix
    xtensa: define __fls
    mn10300: define __fls
    m32r: define __fls
    h8300: define __fls
    frv: define __fls
    cris: define __fls
    cpumask: CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
    cpumask: zero extra bits in alloc_cpumask_var_node
    cpumask: replace for_each_cpu_mask_nr with for_each_cpu in kernel/time/
    cpumask: convert mm/
    ...

    Linus Torvalds
     

01 Jan, 2009

2 commits


29 Dec, 2008

3 commits

  • Fix variable uninitialisation warnings introduced in:

    commit 8bbf4976b59fc9fc2861e79cab7beb3f6d647640
    Author: David Howells
    Date: Fri Nov 14 10:39:14 2008 +1100

    KEYS: Alter use of key instantiation link-to-keyring argument

    As:

    security/keys/keyctl.c: In function 'keyctl_negate_key':
    security/keys/keyctl.c:976: warning: 'dest_keyring' may be used uninitialized in this function
    security/keys/keyctl.c: In function 'keyctl_instantiate_key':
    security/keys/keyctl.c:898: warning: 'dest_keyring' may be used uninitialized in this function

    Some versions of gcc notice that get_instantiation_key() doesn't always set
    *_dest_keyring, but fail to observe that if this happens then *_dest_keyring
    will not be read by the caller.

    Reported-by: Linus Torvalds
    Signed-off-by: David Howells
    Signed-off-by: James Morris

    David Howells
     
  • James Morris
     
  • * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1429 commits)
    net: Allow dependancies of FDDI & Tokenring to be modular.
    igb: Fix build warning when DCA is disabled.
    net: Fix warning fallout from recent NAPI interface changes.
    gro: Fix potential use after free
    sfc: If AN is enabled, always read speed/duplex from the AN advertising bits
    sfc: When disabling the NIC, close the device rather than unregistering it
    sfc: SFT9001: Add cable diagnostics
    sfc: Add support for multiple PHY self-tests
    sfc: Merge top-level functions for self-tests
    sfc: Clean up PHY mode management in loopback self-test
    sfc: Fix unreliable link detection in some loopback modes
    sfc: Generate unique names for per-NIC workqueues
    802.3ad: use standard ethhdr instead of ad_header
    802.3ad: generalize out mac address initializer
    802.3ad: initialize ports LACPDU from const initializer
    802.3ad: remove typedef around ad_system
    802.3ad: turn ports is_individual into a bool
    802.3ad: turn ports is_enabled into a bool
    802.3ad: make ntt bool
    ixgbe: Fix set_ringparam in ixgbe to use the same memory pools.
    ...

    Fixed trivial IPv4/6 address printing conflicts in fs/cifs/connect.c due
    to the conversion to %pI (in this networking merge) and the addition of
    doing IPv6 addresses (from the earlier merge of CIFS).

    Linus Torvalds
     

25 Dec, 2008

1 commit

  • 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
    To: Casey Schaufler
    Cc: Ahmed S. Darwish
    Cc: LSM
    Cc: LKLM

    Acked-by: Casey Schaufler

    Sergio Luis
     

20 Dec, 2008

3 commits


25 Nov, 2008

1 commit

  • Impact: fix sparse warnings

    Fix the following sparse warnings:

    security/security.c:228:2: warning: returning void-valued expression
    security/security.c:233:2: warning: returning void-valued expression
    security/security.c:616:2: warning: returning void-valued expression

    Signed-off-by: Hannes Eder
    Signed-off-by: James Morris

    Hannes Eder
     

15 Nov, 2008

1 commit


14 Nov, 2008

20 commits

  • 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 [Smack changes]
    Signed-off-by: David Howells
    Signed-off-by: James Morris

    David Howells
     
  • Add a 'kernel_service' object class to SELinux and give this object class two
    access vectors: 'use_as_override' and 'create_files_as'.

    The first vector is used to grant a process the right to nominate an alternate
    process security ID for the kernel to use as an override for the SELinux
    subjective security when accessing stuff on behalf of another process.

    For example, CacheFiles when accessing the cache on behalf on a process
    accessing an NFS file needs to use a subjective security ID appropriate to the
    cache rather then the one the calling process is using. The cachefilesd
    daemon will nominate the security ID to be used.

    The second vector is used to grant a process the right to nominate a file
    creation label for a kernel service to use.

    Signed-off-by: David Howells
    Signed-off-by: James Morris

    David Howells
     
  • Differentiate the objective and real subjective credentials from the effective
    subjective credentials on a task by introducing a second credentials pointer
    into the task_struct.

    task_struct::real_cred then refers to the objective and apparent real
    subjective credentials of a task, as perceived by the other tasks in the
    system.

    task_struct::cred then refers to the effective subjective credentials of a
    task, as used by that task when it's actually running. These are not visible
    to the other tasks in the system.

    __task_cred(task) then refers to the objective/real credentials of the task in
    question.

    current_cred() refers to the effective subjective credentials of the current
    task.

    prepare_creds() uses the objective creds as a base and commit_creds() changes
    both pointers in the task_struct (indeed commit_creds() requires them to be the
    same).

    override_creds() and revert_creds() change the subjective creds pointer only,
    and the former returns the old subjective creds. These are used by NFSD,
    faccessat() and do_coredump(), and will by used by CacheFiles.

    In SELinux, current_has_perm() is provided as an alternative to
    task_has_perm(). This uses the effective subjective context of current,
    whereas task_has_perm() uses the objective/real context of the subject.

    Signed-off-by: David Howells
    Signed-off-by: James Morris

    David Howells
     
  • Prettify commoncap.c.

    Signed-off-by: David Howells
    Acked-by: Serge Hallyn
    Reviewed-by: James Morris
    Signed-off-by: James Morris

    David 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
    Acked-by: James Morris
    Acked-by: Serge Hallyn
    Signed-off-by: James Morris

    David 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
    Acked-by: James Morris
    Signed-off-by: James Morris

    David Howells
     
  • Pass credentials through dentry_open() so that the COW creds patch can have
    SELinux's flush_unauthorized_files() pass the appropriate creds back to itself
    when it opens its null chardev.

    The security_dentry_open() call also now takes a creds pointer, as does the
    dentry_open hook in struct security_operations.

    Signed-off-by: David Howells
    Acked-by: James Morris
    Signed-off-by: James Morris

    David Howells
     
  • Make inode_has_perm() and file_has_perm() take a cred pointer rather than a
    task pointer.

    Signed-off-by: David Howells
    Acked-by: James Morris
    Acked-by: Serge Hallyn
    Signed-off-by: James Morris

    David Howells
     
  • Separate per-task-group keyrings from signal_struct and dangle their anchor
    from the cred struct rather than the signal_struct.

    Signed-off-by: David Howells
    Reviewed-by: James Morris
    Signed-off-by: James Morris

    David Howells
     
  • Wrap access to SELinux's task SID, using task_sid() and current_sid() as
    appropriate.

    Signed-off-by: David Howells
    Acked-by: James Morris
    Signed-off-by: James Morris

    David 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
    Acked-by: James Morris
    Acked-by: Serge Hallyn
    Signed-off-by: James Morris

    David Howells
     
  • Wrap current->cred and a few other accessors to hide their actual
    implementation.

    Signed-off-by: David Howells
    Acked-by: James Morris
    Acked-by: Serge Hallyn
    Signed-off-by: James Morris

    David Howells
     
  • Detach the credentials from task_struct, duplicating them in copy_process()
    and releasing them in __put_task_struct().

    Signed-off-by: David Howells
    Acked-by: James Morris
    Acked-by: Serge Hallyn
    Signed-off-by: James Morris

    David 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

    Signed-off-by: David Howells
    Acked-by: James Morris
    Acked-by: Serge Hallyn
    Signed-off-by: James Morris

    David Howells
     
  • Constify the kernel_cap_t arguments to the capset LSM hooks.

    Signed-off-by: David Howells
    Acked-by: Serge Hallyn
    Acked-by: James Morris
    Signed-off-by: James Morris

    David Howells
     
  • Take away the ability for sys_capset() to affect processes other than current.

    This means that current will not need to lock its own credentials when reading
    them against interference by other processes.

    This has effectively been the case for a while anyway, since:

    (1) Without LSM enabled, sys_capset() is disallowed.

    (2) With file-based capabilities, sys_capset() is neutered.

    Signed-off-by: David Howells
    Acked-by: Serge Hallyn
    Acked-by: Andrew G. Morgan
    Acked-by: James Morris
    Signed-off-by: James Morris

    David Howells
     
  • Alter the use of the key instantiation and negation functions' link-to-keyring
    arguments. Currently this specifies a keyring in the target process to link
    the key into, creating the keyring if it doesn't exist. This, however, can be
    a problem for copy-on-write credentials as it means that the instantiating
    process can alter the credentials of the requesting process.

    This patch alters the behaviour such that:

    (1) If keyctl_instantiate_key() or keyctl_negate_key() are given a specific
    keyring by ID (ringid >= 0), then that keyring will be used.

    (2) If keyctl_instantiate_key() or keyctl_negate_key() are given one of the
    special constants that refer to the requesting process's keyrings
    (KEY_SPEC_*_KEYRING, all | Instantiator |------->| Instantiator |
    | | | | | |
    +-----------+ +--------------+ +--------------+
    request_key() request_key()

    This might be useful, for example, in Kerberos, where the requestor requests a
    ticket, and then the ticket instantiator requests the TGT, which someone else
    then has to go and fetch. The TGT, however, should be retained in the
    keyrings of the requestor, not the first instantiator. To make this explict
    an extra special keyring constant is also added.

    Signed-off-by: David Howells
    Reviewed-by: James Morris
    Signed-off-by: James Morris

    David Howells
     
  • Disperse the bits of linux/key_ui.h as the reason they were put here (keyfs)
    didn't get in.

    Signed-off-by: David Howells
    Reviewed-by: James Morris
    Signed-off-by: James Morris

    David Howells
     
  • Wrap access to task credentials so that they can be separated more easily from
    the task_struct during the introduction of COW creds.

    Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

    Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
    sense to use RCU directly rather than a convenient wrapper; these will be
    addressed by later patches.

    Signed-off-by: David Howells
    Reviewed-by: James Morris
    Acked-by: Serge Hallyn
    Cc: Andrew G. Morgan
    Signed-off-by: James Morris

    David Howells
     
  • Wrap access to task credentials so that they can be separated more easily from
    the task_struct during the introduction of COW creds.

    Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

    Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
    sense to use RCU directly rather than a convenient wrapper; these will be
    addressed by later patches.

    Signed-off-by: David Howells
    Reviewed-by: James Morris
    Acked-by: Serge Hallyn
    Signed-off-by: James Morris

    David Howells
     

12 Nov, 2008

1 commit


11 Nov, 2008

3 commits

  • check when determining if a process has additional powers to override
    memory limits or when trying to read/write illegal file labels. Use
    the new noaudit call instead.

    Signed-off-by: Eric Paris
    Acked-by: Stephen Smalley
    Signed-off-by: James Morris

    Eric Paris
     
  • make an A or B type decision instead of a security decision. Currently
    this is the case at least for filesystems when deciding if a process can use
    the reserved 'root' blocks and for the case of things like the oom
    algorithm determining if processes are root processes and should be less
    likely to be killed. These types of security system requests should not be
    audited or logged since they are not really security decisions. It would be
    possible to solve this problem like the vm_enough_memory security check did
    by creating a new LSM interface and moving all of the policy into that
    interface but proves the needlessly bloat the LSM and provide complex
    indirection.

    This merely allows those decisions to be made where they belong and to not
    flood logs or printk with denials for thing that are not security decisions.

    Signed-off-by: Eric Paris
    Acked-by: Stephen Smalley
    Signed-off-by: James Morris

    Eric Paris
     
  • non-zero pE we will crate a new audit record which contains the entire set
    of known information about the executable in question, fP, fI, fE, fversion
    and includes the process's pE, pI, pP. Before and after the bprm capability
    are applied. This record type will only be emitted from execve syscalls.

    an example of making ping use fcaps instead of setuid:

    setcap "cat_net_raw+pe" /bin/ping

    type=SYSCALL msg=audit(1225742021.015:236): arch=c000003e syscall=59 success=yes exit=0 a0=1457f30 a1=14606b0 a2=1463940 a3=321b770a70 items=2 ppid=2929 pid=2963 auid=0 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=pts0 ses=3 comm="ping" exe="/bin/ping" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
    type=UNKNOWN[1321] msg=audit(1225742021.015:236): fver=2 fp=0000000000002000 fi=0000000000000000 fe=1 old_pp=0000000000000000 old_pi=0000000000000000 old_pe=0000000000000000 new_pp=0000000000002000 new_pi=0000000000000000 new_pe=0000000000002000
    type=EXECVE msg=audit(1225742021.015:236): argc=2 a0="ping" a1="127.0.0.1"
    type=CWD msg=audit(1225742021.015:236): cwd="/home/test"
    type=PATH msg=audit(1225742021.015:236): item=0 name="/bin/ping" inode=49256 dev=fd:00 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ping_exec_t:s0 cap_fp=0000000000002000 cap_fe=1 cap_fver=2
    type=PATH msg=audit(1225742021.015:236): item=1 name=(null) inode=507915 dev=fd:00 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ld_so_t:s0

    Signed-off-by: Eric Paris
    Acked-by: Serge Hallyn
    Signed-off-by: James Morris

    Eric Paris