Eric Lee / smarc-ti-linux-kernel

05 Jan, 2009

12 commits

25 Dec, 2008

1 commit

09 Dec, 2008

3 commits

14 Nov, 2008

4 commits

  • d84f4f992   CRED: Inaugurate COW credentials ... Browse Code »
    2

    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
     
  • c69e8d9c0   CRED: Use RCU to access another task's creds and to release a task's own creds ... Browse Code »

    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
     
  • b6dff3ec5   CRED: Separate task security context from task_struct ... Browse Code »

    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
     
  • 76aac0e9a   CRED: Wrap task credential accesses in the core kernel ... Browse Code »

    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: Al Viro
    Cc: linux-audit@redhat.com
    Cc: containers@lists.linux-foundation.org
    Cc: linux-mm@kvack.org
    Signed-off-by: James Morris

    David Howells
     

11 Nov, 2008

3 commits

  • e68b75a02   When the capset syscall is used it is not possible for audit to record the ... Browse Code »

    actual capbilities being added/removed. This patch adds a new record type
    which emits the target pid and the eff, inh, and perm cap sets.

    example output if you audit capset syscalls would be:

    type=SYSCALL msg=audit(1225743140.465:76): arch=c000003e syscall=126 success=yes exit=0 a0=17f2014 a1=17f201c a2=80000000 a3=7fff2ab7f060 items=0 ppid=2160 pid=2223 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=1 comm="setcap" exe="/usr/sbin/setcap" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
    type=UNKNOWN[1322] msg=audit(1225743140.465:76): pid=0 cap_pi=ffffffffffffffff cap_pp=ffffffffffffffff cap_pe=ffffffffffffffff

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

    Eric Paris
     
  • 3fc689e96   Any time fcaps or a setuid app under SECURE_NOROOT is used to result in a ... Browse Code »

    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
     
  • 851f7ff56   This patch will print cap_permitted and cap_inheritable data in the PATH ... Browse Code »

    records of any file that has file capabilities set. Files which do not
    have fcaps set will not have different PATH records.

    An example audit record if you run:
    setcap "cap_net_admin+pie" /bin/bash
    /bin/bash

    type=SYSCALL msg=audit(1225741937.363:230): arch=c000003e syscall=59 success=yes exit=0 a0=2119230 a1=210da30 a2=20ee290 a3=8 items=2 ppid=2149 pid=2923 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=3 comm="ping" exe="/bin/ping" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
    type=EXECVE msg=audit(1225741937.363:230): argc=2 a0="ping" a1="www.google.com"
    type=CWD msg=audit(1225741937.363:230): cwd="/root"
    type=PATH msg=audit(1225741937.363:230): item=0 name="/bin/ping" inode=49256 dev=fd:00 mode=0104755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ping_exec_t:s0 cap_fp=0000000000002000 cap_fi=0000000000002000 cap_fe=1 cap_fver=2
    type=PATH msg=audit(1225741937.363:230): 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
     

14 Oct, 2008

1 commit

02 Sep, 2008

1 commit

04 Aug, 2008

1 commit

02 Aug, 2008

2 commits

  • 980dfb0db   [PATCH] Fix the kernel panic of audit_filter_task when key field is set ... Browse Code »

    When calling audit_filter_task(), it calls audit_filter_rules() with audit_context is NULL.
    If the key field is set, the result in audit_filter_rules() will be set to 1 and
    ctx->filterkey will be set to key.
    But the ctx is NULL in this condition, so kernel will panic.

    Signed-off-by: Zhang Xiliang
    Signed-off-by: Al Viro

    zhangxiliang
     
  • ee1d31566   [PATCH] Audit: Collect signal info when SIGUSR2 is sent to auditd ... Browse Code »

    Makes the kernel audit subsystem collect information about the sending
    process when that process sends SIGUSR2 to the userspace audit daemon.
    SIGUSR2 is a new interesting signal to auditd telling auditd that it
    should try to start logging to disk again and the error condition which
    caused it to stop logging to disk (usually out of space) has been
    rectified.

    Signed-off-by: Eric Paris
    Signed-off-by: Al Viro

    Eric Paris
     

24 Jul, 2008

1 commit

  • 86a1c34a9   x86_64 syscall audit fast-path ... Browse Code »

    This adds a fast path for 64-bit syscall entry and exit when
    TIF_SYSCALL_AUDIT is set, but no other kind of syscall tracing.
    This path does not need to save and restore all registers as
    the general case of tracing does. Avoiding the iret return path
    when syscall audit is enabled helps performance a lot.

    Signed-off-by: Roland McGrath

    Roland McGrath
     

28 Apr, 2008

5 commits

  • 8b67dca94   [PATCH] new predicate - AUDIT_FILETYPE ... Browse Code »

    Argument is S_IF... | , where index is normally 0 or 1.
    Triggers if chosen element of ctx->names[] is present and the
    mode of object in question matches the upper bits of argument.
    I.e. for things like "is the argument of that chmod a directory",
    etc.

    Signed-off-by: Al Viro

    Al Viro
     
  • 7719e437f   [PATCH 2/2] audit: fix sparse shadowed variable warnings ... Browse Code »

    Use msglen as the identifier.
    kernel/audit.c:724:10: warning: symbol 'len' shadows an earlier one
    kernel/audit.c:575:8: originally declared here

    Don't use ino_f to check the inode field at the end of the functions.
    kernel/auditfilter.c:429:22: warning: symbol 'f' shadows an earlier one
    kernel/auditfilter.c:420:21: originally declared here
    kernel/auditfilter.c:542:22: warning: symbol 'f' shadows an earlier one
    kernel/auditfilter.c:529:21: originally declared here

    i always used as a counter for a for loop and initialized to zero before
    use. Eliminate the inner i variables.
    kernel/auditsc.c:1295:8: warning: symbol 'i' shadows an earlier one
    kernel/auditsc.c:1152:6: originally declared here
    kernel/auditsc.c:1320:7: warning: symbol 'i' shadows an earlier one
    kernel/auditsc.c:1152:6: originally declared here

    Signed-off-by: Harvey Harrison
    Signed-off-by: Al Viro

    Harvey Harrison
     
  • c782f242f   [PATCH 1/2] audit: move extern declarations to audit.h ... Browse Code »

    Leave audit_sig_{uid|pid|sid} protected by #ifdef CONFIG_AUDITSYSCALL.

    Noticed by sparse:
    kernel/audit.c:73:6: warning: symbol 'audit_ever_enabled' was not declared. Should it be static?
    kernel/audit.c:100:8: warning: symbol 'audit_sig_uid' was not declared. Should it be static?
    kernel/audit.c:101:8: warning: symbol 'audit_sig_pid' was not declared. Should it be static?
    kernel/audit.c:102:6: warning: symbol 'audit_sig_sid' was not declared. Should it be static?
    kernel/audit.c:117:23: warning: symbol 'audit_ih' was not declared. Should it be static?
    kernel/auditfilter.c:78:18: warning: symbol 'audit_filter_list' was not declared. Should it be static?

    Signed-off-by: Harvey Harrison
    Signed-off-by: Al Viro

    Harvey Harrison
     
  • b556f8ad5   Audit: standardize string audit interfaces ... Browse Code »

    This patch standardized the string auditing interfaces. No userspace
    changes will be visible and this is all just cleanup and consistancy
    work. We have the following string audit interfaces to use:

    void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, size_t len);

    void audit_log_n_string(struct audit_buffer *ab, const char *buf, size_t n);
    void audit_log_string(struct audit_buffer *ab, const char *buf);

    void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, size_t n);
    void audit_log_untrustedstring(struct audit_buffer *ab, const char *string);

    This may be the first step to possibly fixing some of the issues that
    people have with the string output from the kernel audit system. But we
    still don't have an agreed upon solution to that problem.

    Signed-off-by: Eric Paris
    Signed-off-by: Al Viro

    Eric Paris
     
  • 436c405c7   Audit: end printk with newline ... Browse Code »

    A couple of audit printk statements did not have a newline.

    Signed-off-by: Eric Paris
    Signed-off-by: Al Viro

    Eric Paris
     

19 Apr, 2008

3 commits

  • 04305e4af   Audit: Final renamings and cleanup ... Browse Code »

    Rename the se_str and se_rule audit fields elements to
    lsm_str and lsm_rule to avoid confusion.

    Signed-off-by: Casey Schaufler
    Signed-off-by: Ahmed S. Darwish
    Acked-by: James Morris

    Ahmed S. Darwish
     
  • d7a96f3a1   Audit: internally use the new LSM audit hooks ... Browse Code »

    Convert Audit to use the new LSM Audit hooks instead of
    the exported SELinux interface.

    Basically, use:
    security_audit_rule_init
    secuirty_audit_rule_free
    security_audit_rule_known
    security_audit_rule_match

    instad of (respectively) :
    selinux_audit_rule_init
    selinux_audit_rule_free
    audit_rule_has_selinux
    selinux_audit_rule_match

    Signed-off-by: Casey Schaufler
    Signed-off-by: Ahmed S. Darwish
    Acked-by: James Morris

    Ahmed S. Darwish
     
  • 2a862b32f   Audit: use new LSM hooks instead of SELinux exports ... Browse Code »

    Stop using the following exported SELinux interfaces:
    selinux_get_inode_sid(inode, sid)
    selinux_get_ipc_sid(ipcp, sid)
    selinux_get_task_sid(tsk, sid)
    selinux_sid_to_string(sid, ctx, len)
    kfree(ctx)

    and use following generic LSM equivalents respectively:
    security_inode_getsecid(inode, secid)
    security_ipc_getsecid*(ipcp, secid)
    security_task_getsecid(tsk, secid)
    security_sid_to_secctx(sid, ctx, len)
    security_release_secctx(ctx, len)

    Call security_release_secctx only if security_secid_to_secctx
    succeeded.

    Signed-off-by: Casey Schaufler
    Signed-off-by: Ahmed S. Darwish
    Acked-by: James Morris
    Reviewed-by: Paul Moore

    Ahmed S. Darwish
     

01 Mar, 2008

1 commit

  • 422b03cf7   [PATCH] Audit: Fix the format type for size_t variables ... Browse Code »

    Fix the following compiler warning by using "%zu" as defined in C99.

    CC kernel/auditsc.o
    kernel/auditsc.c: In function 'audit_log_single_execve_arg':
    kernel/auditsc.c:1074: warning: format '%ld' expects type 'long int', but
    argument 4 has type 'size_t'

    Signed-off-by: Paul Moore
    Signed-off-by: Al Viro

    Paul Moore
     

19 Feb, 2008

1 commit

  • b0abcfc14   Audit: use == not = in if statements ... Browse Code »

    Clearly this was supposed to be an == not an = in the if statement.
    This patch also causes us to stop processing execve args once we have
    failed rather than continuing to loop on failure over and over and over.

    Signed-off-by: Eric Paris
    Acked-by: Al Viro
    Signed-off-by: Al Viro
    Signed-off-by: Linus Torvalds

    Eric Paris
     

15 Feb, 2008

1 commit

  • 44707fdf5   d_path: Use struct path in struct avc_audit_data ... Browse Code »

    audit_log_d_path() is a d_path() wrapper that is used by the audit code. To
    use a struct path in audit_log_d_path() I need to embed it into struct
    avc_audit_data.

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: Jan Blunck
    Acked-by: Christoph Hellwig
    Cc: Al Viro
    Cc: "J. Bruce Fields"
    Cc: Neil Brown
    Cc: Stephen Smalley
    Cc: James Morris
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jan Blunck