18 Aug, 2010

1 commit

  • fs: cleanup files_lock locking

    Lock tty_files with a new spinlock, tty_files_lock; provide helpers to
    manipulate the per-sb files list; unexport the files_lock spinlock.

    Cc: linux-kernel@vger.kernel.org
    Cc: Christoph Hellwig
    Cc: Alan Cox
    Acked-by: Andi Kleen
    Acked-by: Greg Kroah-Hartman
    Signed-off-by: Nick Piggin
    Signed-off-by: Al Viro

    Nick Piggin
     

11 Aug, 2010

2 commits

  • Signed-off-by: Dmitry Torokhov
    Acked-by: Arnd Bergmann
    Acked-by: John Kacur
    Cc: Al Viro
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Dmitry Torokhov
     
  • * 'for-linus' of git://git.infradead.org/users/eparis/notify: (132 commits)
    fanotify: use both marks when possible
    fsnotify: pass both the vfsmount mark and inode mark
    fsnotify: walk the inode and vfsmount lists simultaneously
    fsnotify: rework ignored mark flushing
    fsnotify: remove global fsnotify groups lists
    fsnotify: remove group->mask
    fsnotify: remove the global masks
    fsnotify: cleanup should_send_event
    fanotify: use the mark in handler functions
    audit: use the mark in handler functions
    dnotify: use the mark in handler functions
    inotify: use the mark in handler functions
    fsnotify: send fsnotify_mark to groups in event handling functions
    fsnotify: Exchange list heads instead of moving elements
    fsnotify: srcu to protect read side of inode and vfsmount locks
    fsnotify: use an explicit flag to indicate fsnotify_destroy_mark has been called
    fsnotify: use _rcu functions for mark list traversal
    fsnotify: place marks on object in order of group memory address
    vfs/fsnotify: fsnotify_close can delay the final work in fput
    fsnotify: store struct file not struct path
    ...

    Fix up trivial delete/modify conflict in fs/notify/inotify/inotify.c.

    Linus Torvalds
     

02 Aug, 2010

2 commits

  • Currently MAY_ACCESS means that filesystems must check the permissions
    right then and not rely on cached results or the results of future
    operations on the object. This can be because of a call to sys_access() or
    because of a call to chdir() which needs to check search without relying on
    any future operations inside that dir. I plan to use MAY_ACCESS for other
    purposes in the security system, so I split the MAY_ACCESS and the
    MAY_CHDIR cases.

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

    Eric Paris
     
  • When commit be6d3e56a6b9b3a4ee44a0685e39e595073c6f0d "introduce new LSM hooks
    where vfsmount is available." was proposed, regarding security_path_truncate(),
    only "struct file *" argument (which AppArmor wanted to use) was removed.
    But length and time_attrs arguments are not used by TOMOYO nor AppArmor.
    Thus, let's remove these arguments.

    Signed-off-by: Tetsuo Handa
    Acked-by: Nick Piggin
    Signed-off-by: James Morris

    Tetsuo Handa
     

28 Jul, 2010

2 commits


22 May, 2010

1 commit


30 Mar, 2010

1 commit

  • …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
     

06 Mar, 2010

1 commit

  • * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: (33 commits)
    quota: stop using QUOTA_OK / NO_QUOTA
    dquot: cleanup dquot initialize routine
    dquot: move dquot initialization responsibility into the filesystem
    dquot: cleanup dquot drop routine
    dquot: move dquot drop responsibility into the filesystem
    dquot: cleanup dquot transfer routine
    dquot: move dquot transfer responsibility into the filesystem
    dquot: cleanup inode allocation / freeing routines
    dquot: cleanup space allocation / freeing routines
    ext3: add writepage sanity checks
    ext3: Truncate allocated blocks if direct IO write fails to update i_size
    quota: Properly invalidate caches even for filesystems with blocksize < pagesize
    quota: generalize quota transfer interface
    quota: sb_quota state flags cleanup
    jbd: Delay discarding buffers in journal_unmap_buffer
    ext3: quota_write cross block boundary behaviour
    quota: drop permission checks from xfs_fs_set_xstate/xfs_fs_set_xquota
    quota: split out compat_sys_quotactl support from quota.c
    quota: split out netlink notification support from quota.c
    quota: remove invalid optimization from quota_sync_all
    ...

    Fixed trivial conflicts in fs/namei.c and fs/ufs/inode.c

    Linus Torvalds
     

05 Mar, 2010

1 commit

  • Currently various places in the VFS call vfs_dq_init directly. This means
    we tie the quota code into the VFS. Get rid of that and make the
    filesystem responsible for the initialization. For most metadata operations
    this is a straight forward move into the methods, but for truncate and
    open it's a bit more complicated.

    For truncate we currently only call vfs_dq_init for the sys_truncate case
    because open already takes care of it for ftruncate and open(O_TRUNC) - the
    new code causes an additional vfs_dq_init for those which is harmless.

    For open the initialization is moved from do_filp_open into the open method,
    which means it happens slightly earlier now, and only for regular files.
    The latter is fine because we don't need to initialize it for operations
    on special files, and we already do it as part of the namespace operations
    for directories.

    Add a dquot_file_open helper that filesystems that support generic quotas
    can use to fill in ->open.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Jan Kara

    Christoph Hellwig
     

04 Mar, 2010

1 commit


23 Dec, 2009

2 commits


17 Dec, 2009

2 commits

  • * do ima_get_count() in __dentry_open()
    * stop doing that in followups
    * move ima_path_check() to right after nameidata_to_filp()
    * don't bump counters on it

    Signed-off-by: Al Viro

    Al Viro
     
  • All users outside of fs/ of get_empty_filp() have been removed. This patch
    moves the definition from the include/ directory to internal.h so no new
    users crop up and removes the EXPORT_SYMBOL. I'd love to see open intents
    stop using it too, but that's a problem for another day and a smarter
    developer!

    Signed-off-by: Eric Paris
    Acked-by: Miklos Szeredi
    Signed-off-by: Al Viro

    Eric Paris
     

24 Nov, 2009

1 commit


12 Oct, 2009

2 commits


24 Sep, 2009

1 commit

  • For this system call user space passes a signed long length parameter,
    while the kernel side takes an unsigned long parameter and converts it
    later to signed long again.

    This has led to bugs in compat wrappers see e.g. dd90bbd5 "powerpc: Add
    compat_sys_truncate". The s390 compat wrapper for this functions is
    broken as well since it also performs zero extension instead of sign
    extension for the length parameter.

    In addition if hpa comes up with an automated way of generating
    compat wrappers it would generate a wrong one here.

    So change the length parameter from unsigned long to long.

    Cc: "H. Peter Anvin"
    Cc: Al Viro
    Cc: Christoph Hellwig
    Signed-off-by: Heiko Carstens
    Signed-off-by: Linus Torvalds

    Heiko Carstens
     

02 Sep, 2009

1 commit

  • Add a config option (CONFIG_DEBUG_CREDENTIALS) to turn on some debug checking
    for credential management. The additional code keeps track of the number of
    pointers from task_structs to any given cred struct, and checks to see that
    this number never exceeds the usage count of the cred struct (which includes
    all references, not just those from task_structs).

    Furthermore, if SELinux is enabled, the code also checks that the security
    pointer in the cred struct is never seen to be invalid.

    This attempts to catch the bug whereby inode_has_perm() faults in an nfsd
    kernel thread on seeing cred->security be a NULL pointer (it appears that the
    credential struct has been previously released):

    http://www.kerneloops.org/oops.php?number=252883

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

    David Howells
     

21 Aug, 2009

1 commit

  • When suid is set and the non-owner user has write permission, any writing
    into this file should be allowed and suid should be removed after that.

    However, current kernel only allows writing without truncations, when we
    do truncations on that file, we get EPERM. This is a bug.

    Steps to reproduce this bug:

    % ls -l rootdir/file1
    -rwsrwsrwx 1 root root 3 Jun 25 15:42 rootdir/file1
    % echo h > rootdir/file1
    zsh: operation not permitted: rootdir/file1
    % ls -l rootdir/file1
    -rwsrwsrwx 1 root root 3 Jun 25 15:42 rootdir/file1
    % echo h >> rootdir/file1
    % ls -l rootdir/file1
    -rwxrwxrwx 1 root root 5 Jun 25 16:34 rootdir/file1

    Signed-off-by: WANG Cong
    Cc: Eric Sandeen
    Acked-by: Eric Paris
    Cc: Eugene Teo
    Cc: Al Viro
    Cc: OGAWA Hirofumi
    Cc: Christoph Hellwig
    Cc: Stephen Smalley
    Signed-off-by: Andrew Morton
    Signed-off-by: James Morris

    Amerigo Wang
     

24 Jun, 2009

1 commit


12 Jun, 2009

1 commit

  • This patch speeds up lmbench lat_mmap test by about another 2% after the
    first patch.

    Before:
    avg = 462.286
    std = 5.46106

    After:
    avg = 453.12
    std = 9.58257

    (50 runs of each, stddev gives a reasonable confidence)

    It does this by introducing mnt_clone_write, which avoids some heavyweight
    operations of mnt_want_write if called on a vfsmount which we know already
    has a write count; and mnt_want_write_file, which can call mnt_clone_write
    if the file is open for write.

    After these two patches, mnt_want_write and mnt_drop_write go from 7% on
    the profile down to 1.3% (including mnt_clone_write).

    [AV: mnt_want_write_file() should take file alone and derive mnt from it;
    not only all callers have that form, but that's the only mnt about which
    we know that it's already held for write if file is opened for write]

    Cc: Dave Hansen
    Signed-off-by: Nick Piggin
    Signed-off-by: Al Viro

    npiggin@suse.de
     

09 May, 2009

1 commit


01 Apr, 2009

1 commit


26 Mar, 2009

1 commit


14 Jan, 2009

9 commits


06 Jan, 2009

1 commit

  • 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
     

01 Jan, 2009

1 commit


14 Nov, 2008

2 commits

  • 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