Eric Lee / smarc-fsl-linux-kernel

27 Apr, 2011

1 commit

  • f56298835   audit: acquire creds selectively to reduce atomic op overhead ... Browse Code »

    Commit c69e8d9c01db ("CRED: Use RCU to access another task's creds and to
    release a task's own creds") added calls to get_task_cred and put_cred in
    audit_filter_rules. Profiling with a large number of audit rules active
    on the exit chain shows that we are spending upto 48% in this routine for
    syscall intensive tests, most of which is in the atomic ops.

    1. The code should be accessing tsk->cred rather than tsk->real_cred.
    2. Since tsk is current (or tsk is being created by copy_process) access to
    tsk->cred without rcu read lock is possible. At the request of the audit
    maintainer, a new flag has been added to audit_filter_rules in order to make
    this explicit and guide future code.

    Signed-off-by: Tony Jones
    Acked-by: Eric Paris
    Signed-off-by: Jiri Kosina

    Tony Jones
     

31 Mar, 2011

1 commit

30 Oct, 2010

1 commit

  • 120a795da   audit mmap ... Browse Code »

    Normal syscall audit doesn't catch 5th argument of syscall. It also
    doesn't catch the contents of userland structures pointed to be
    syscall argument, so for both old and new mmap(2) ABI it doesn't
    record the descriptor we are mapping. For old one it also misses
    flags.

    Signed-off-by: Al Viro

    Al Viro
     

11 Aug, 2010

1 commit

28 Jul, 2010

4 commits

06 Apr, 2010

1 commit

  • 449cedf09   audit: preface audit printk with audit ... Browse Code »

    There have been a number of reports of people seeing the message:
    "name_count maxed, losing inode data: dev=00:05, inode=3185"
    in dmesg. These usually lead to people reporting problems to the filesystem
    group who are in turn clueless what they mean.

    Eventually someone finds me and I explain what is going on and that
    these come from the audit system. The basics of the problem is that the
    audit subsystem never expects a single syscall to 'interact' (for some
    wish washy meaning of interact) with more than 20 inodes. But in fact
    some operations like loading kernel modules can cause changes to lots of
    inodes in debugfs.

    There are a couple real fixes being bandied about including removing the
    fixed compile time limit of 20 or not auditing changes in debugfs (or
    both) but neither are small and obvious so I am not sending them for
    immediate inclusion (I hope Al forwards a real solution next devel
    window).

    In the meantime this patch simply adds 'audit' to the beginning of the
    crap message so if a user sees it, they come blame me first and we can
    talk about what it means and make sure we understand all of the reasons
    it can happen and make sure this gets solved correctly in the long run.

    Signed-off-by: Eric Paris
    Signed-off-by: Linus Torvalds

    Eric Paris
     

30 Mar, 2010

1 commit

  • 5a0e3ad6a   include cleanup: Update gfp.h and slab.h includes to prepare for breaking implic… ... Browse Code »

    …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

09 Feb, 2010

1 commit

23 Dec, 2009

1 commit

  • 5300990c0   Sanitize f_flags helpers ... Browse Code »

    * pull ACC_MODE to fs.h; we have several copies all over the place
    * nightmarish expression calculating f_mode by f_flags deserves a helper
    too (OPEN_FMODE(flags))

    Signed-off-by: Al Viro

    Al Viro
     

24 Sep, 2009

1 commit

24 Jun, 2009

4 commits

  • 916d75761   Fix rule eviction order for AUDIT_DIR ... Browse Code »

    If syscall removes the root of subtree being watched, we
    definitely do not want the rules refering that subtree
    to be destroyed without the syscall in question having
    a chance to match them.

    Signed-off-by: Al Viro

    Al Viro
     
  • 9d9609851   Audit: clean up all op= output to include string quoting ... Browse Code »

    A number of places in the audit system we send an op= followed by a string
    that includes spaces. Somehow this works but it's just wrong. This patch
    moves all of those that I could find to be quoted.

    Example:

    Change From: type=CONFIG_CHANGE msg=audit(1244666690.117:31): auid=0 ses=1
    subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 op=remove rule
    key="number2" list=4 res=0

    Change To: type=CONFIG_CHANGE msg=audit(1244666690.117:31): auid=0 ses=1
    subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 op="remove rule"
    key="number2" list=4 res=0

    Signed-off-by: Eric Paris

    Eric Paris
     
  • cfcad62c7   audit: seperate audit inode watches into a subfile ... Browse Code »

    In preparation for converting audit to use fsnotify instead of inotify we
    seperate the inode watching code into it's own file. This is similar to
    how the audit tree watching code is already seperated into audit_tree.c

    Signed-off-by: Eric Paris

    Eric Paris
     
  • b87ce6e41   Audit: better estimation of execve record length ... Browse Code »

    The audit execve record splitting code estimates the length of the message
    generated. But it forgot to include the "" that wrap each string in its
    estimation. This means that execve messages with lots of tiny (1-2 byte)
    arguments could still cause records greater than 8k to be emitted. Simply
    fix the estimate.

    Signed-off-by: Eric Paris

    Eric Paris
     

06 Apr, 2009

5 commits

  • def575434   Audit: remove spaces from audit_log_d_path ... Browse Code »

    audit_log_d_path had spaces in the strings which would be emitted on the
    error paths. This patch simply replaces those spaces with an _ or removes
    the needless spaces entirely.

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

    Eric Paris
     
  • 679173b72   audit: audit_set_auditable defined but not used ... Browse Code »

    after 0590b9335a1c72a3f0defcc6231287f7817e07c8 audit_set_auditable() is now only
    used by the audit tree code. If CONFIG_AUDIT_TREE is unset it will be defined
    but unused. This patch simply moves the function inside a CONFIG_AUDIT_TREE
    block.

    cc1: warnings being treated as errors
    /home/acme_unencrypted/git/linux-2.6-tip/kernel/auditsc.c:745: error: ‘audit_set_auditable’ defined but not used
    make[2]: *** [kernel/auditsc.o] Error 1
    make[1]: *** [kernel] Error 2
    make[1]: *** Waiting for unfinished jobs....

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

    Eric Paris
     
  • 6d208da89   audit: Fix possible return value truncation in audit_get_context() ... Browse Code »

    The audit subsystem treats syscall return codes as type long, unfortunately
    the audit_get_context() function mistakenly converts the return code to an
    int type in the parameters which could cause problems on systems where the
    sizeof(int) != sizeof(long).

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

    Paul Moore
     
  • 6b9625599   auditsc: fix kernel-doc notation ... Browse Code »

    Fix auditsc kernel-doc notation:

    Warning(linux-2.6.28-git7//kernel/auditsc.c:2156): No description found for parameter 'attr'
    Warning(linux-2.6.28-git7//kernel/auditsc.c:2156): Excess function parameter 'u_attr' description in '__audit_mq_open'
    Warning(linux-2.6.28-git7//kernel/auditsc.c:2204): No description found for parameter 'notification'
    Warning(linux-2.6.28-git7//kernel/auditsc.c:2204): Excess function parameter 'u_notification' description in '__audit_mq_notify'

    Signed-off-by: Randy Dunlap
    cc: Al Viro
    cc: Eric Paris
    Signed-off-by: Al Viro

    Randy Dunlap
     
  • ca96a895a   audit: EXECVE record - removed bogus newline ... Browse Code »

    (updated)
    Added hunk that changes the comment, the rest is the same.

    EXECVE records contain a newline after every argument. auditd converts
    "\n" to " " so you cannot see newlines even in raw logs, but they're
    there nevertheless. If you're not using auditd, you need to work round
    them. These '\n' chars are can be easily replaced by spaces when
    creating record in kernel. Note there is no need for trailing '\n' in
    an audit record.

    record before this patch:
    "type=EXECVE msg=audit(1231421801.566:31): argc=4 a0=\"./test\"\na1=\"a\"\na2=\"b\"\na3=\"c\"\n"

    record after this patch:
    "type=EXECVE msg=audit(1231421801.566:31): argc=4 a0=\"./test\" a1=\"a\" a2=\"b\" a3=\"c\""

    Signed-off-by: Jiri Pirko
    Acked-by: Eric Paris
    Signed-off-by: Al Viro

    Jiri Pirko
     

01 Apr, 2009

1 commit

05 Jan, 2009

12 commits

25 Dec, 2008

1 commit

09 Dec, 2008

3 commits

14 Nov, 2008

1 commit

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

    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