Commit Graph

1214 Commits

Author SHA1 Message Date
Linus Torvalds 426e1f5cec Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
  split invalidate_inodes()
  fs: skip I_FREEING inodes in writeback_sb_inodes
  fs: fold invalidate_list into invalidate_inodes
  fs: do not drop inode_lock in dispose_list
  fs: inode split IO and LRU lists
  fs: switch bdev inode bdi's correctly
  fs: fix buffer invalidation in invalidate_list
  fsnotify: use dget_parent
  smbfs: use dget_parent
  exportfs: use dget_parent
  fs: use RCU read side protection in d_validate
  fs: clean up dentry lru modification
  fs: split __shrink_dcache_sb
  fs: improve DCACHE_REFERENCED usage
  fs: use percpu counter for nr_dentry and nr_dentry_unused
  fs: simplify __d_free
  fs: take dcache_lock inside __d_path
  fs: do not assign default i_ino in new_inode
  fs: introduce a per-cpu last_ino allocator
  new helper: ihold()
  ...
2010-10-26 17:58:44 -07:00
Linus Torvalds f9ba5375a8 Merge branch 'ima-memory-use-fixes'
* ima-memory-use-fixes:
  IMA: fix the ToMToU logic
  IMA: explicit IMA i_flag to remove global lock on inode_delete
  IMA: drop refcnt from ima_iint_cache since it isn't needed
  IMA: only allocate iint when needed
  IMA: move read counter into struct inode
  IMA: use i_writecount rather than a private counter
  IMA: use inode->i_lock to protect read and write counters
  IMA: convert internal flags from long to char
  IMA: use unsigned int instead of long for counters
  IMA: drop the inode opencount since it isn't needed for operation
  IMA: use rbtree instead of radix tree for inode information cache
2010-10-26 11:37:48 -07:00
Eric Paris bade72d607 IMA: fix the ToMToU logic
Current logic looks like this:

        rc = ima_must_measure(NULL, inode, MAY_READ, FILE_CHECK);
        if (rc < 0)
                goto out;

        if (mode & FMODE_WRITE) {
                if (inode->i_readcount)
                        send_tomtou = true;
                goto out;
        }

        if (atomic_read(&inode->i_writecount) > 0)
                send_writers = true;

Lets assume we have a policy which states that all files opened for read
by root must be measured.

Lets assume the file has permissions 777.

Lets assume that root has the given file open for read.

Lets assume that a non-root process opens the file write.

The non-root process will get to ima_counts_get() and will check the
ima_must_measure().  Since it is not supposed to measure it will goto
out.

We should check the i_readcount no matter what since we might be causing
a ToMToU voilation!

This is close to correct, but still not quite perfect.  The situation
could have been that root, which was interested in the mesurement opened
and closed the file and another process which is not interested in the
measurement is the one holding the i_readcount ATM.  This is just overly
strict on ToMToU violations, which is better than not strict enough...

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:19 -07:00
Eric Paris 196f518128 IMA: explicit IMA i_flag to remove global lock on inode_delete
Currently for every removed inode IMA must take a global lock and search
the IMA rbtree looking for an associated integrity structure.  Instead
we explicitly mark an inode when we add an integrity structure so we
only have to take the global lock and do the removal if it exists.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:19 -07:00
Eric Paris 64c62f06be IMA: drop refcnt from ima_iint_cache since it isn't needed
Since finding a struct ima_iint_cache requires a valid struct inode, and
the struct ima_iint_cache is supposed to have the same lifetime as a
struct inode (technically they die together but don't need to be created
at the same time) we don't have to worry about the ima_iint_cache
outliving or dieing before the inode.  So the refcnt isn't useful.  Just
get rid of it and free the structure when the inode is freed.

Signed-off-by: Eric Paris <eapris@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:19 -07:00
Eric Paris bc7d2a3e66 IMA: only allocate iint when needed
IMA always allocates an integrity structure to hold information about
every inode, but only needed this structure to track the number of
readers and writers currently accessing a given inode.  Since that
information was moved into struct inode instead of the integrity struct
this patch stops allocating the integrity stucture until it is needed.
Thus greatly reducing memory usage.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:18 -07:00
Eric Paris a178d2027d IMA: move read counter into struct inode
IMA currently allocated an inode integrity structure for every inode in
core.  This stucture is about 120 bytes long.  Most files however
(especially on a system which doesn't make use of IMA) will never need
any of this space.  The problem is that if IMA is enabled we need to
know information about the number of readers and the number of writers
for every inode on the box.  At the moment we collect that information
in the per inode iint structure and waste the rest of the space.  This
patch moves those counters into the struct inode so we can eventually
stop allocating an IMA integrity structure except when absolutely
needed.

This patch does the minimum needed to move the location of the data.
Further cleanups, especially the location of counter updates, may still
be possible.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:18 -07:00
Eric Paris b9593d309d IMA: use i_writecount rather than a private counter
IMA tracks the number of struct files which are holding a given inode
readonly and the number which are holding the inode write or r/w.  It
needs this information so when a new reader or writer comes in it can
tell if this new file will be able to invalidate results it already made
about existing files.

aka if a task is holding a struct file open RO, IMA measured the file
and recorded those measurements and then a task opens the file RW IMA
needs to note in the logs that the old measurement may not be correct.
It's called a "Time of Measure Time of Use" (ToMToU) issue.  The same is
true is a RO file is opened to an inode which has an open writer.  We
cannot, with any validity, measure the file in question since it could
be changing.

This patch attempts to use the i_writecount field to track writers.  The
i_writecount field actually embeds more information in it's value than
IMA needs but it should work for our purposes and allow us to shrink the
struct inode even more.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:18 -07:00
Eric Paris ad16ad00c3 IMA: use inode->i_lock to protect read and write counters
Currently IMA used the iint->mutex to protect the i_readcount and
i_writecount.  This patch uses the inode->i_lock since we are going to
start using in inode objects and that is the most appropriate lock.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:18 -07:00
Eric Paris 15aac67677 IMA: convert internal flags from long to char
The IMA flags is an unsigned long but there is only 1 flag defined.
Lets save a little space and make it a char.  This packs nicely next to
the array of u8's.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:18 -07:00
Eric Paris 497f323370 IMA: use unsigned int instead of long for counters
Currently IMA uses 2 longs in struct inode.  To save space (and as it
seems impossible to overflow 32 bits) we switch these to unsigned int.
The switch to unsigned does require slightly different checks for
underflow, but it isn't complex.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:18 -07:00
Eric Paris b575156daf IMA: drop the inode opencount since it isn't needed for operation
The opencount was used to help debugging to make sure that everything
which created a struct file also correctly made the IMA calls.  Since we
moved all of that into the VFS this isn't as necessary.  We should be
able to get the same amount of debugging out of just the reader and
write count.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:17 -07:00
Eric Paris 8549164143 IMA: use rbtree instead of radix tree for inode information cache
The IMA code needs to store the number of tasks which have an open fd
granting permission to write a file even when IMA is not in use.  It
needs this information in order to be enabled at a later point in time
without losing it's integrity garantees.

At the moment that means we store a little bit of data about every inode
in a cache.  We use a radix tree key'd on the inode's memory address.
Dave Chinner pointed out that a radix tree is a terrible data structure
for such a sparse key space.  This patch switches to using an rbtree
which should be more efficient.

Bug report from Dave:

 "I just noticed that slabtop was reporting an awfully high usage of
  radix tree nodes:

   OBJS ACTIVE  USE OBJ SIZE  SLABS OBJ/SLAB CACHE SIZE NAME
  4200331 2778082  66%    0.55K 144839       29   2317424K radix_tree_node
  2321500 2060290  88%    1.00K  72581       32   2322592K xfs_inode
  2235648 2069791  92%    0.12K  69864       32    279456K iint_cache

  That is, 2.7M radix tree nodes are allocated, and the cache itself is
  consuming 2.3GB of RAM.  I know that the XFS inodei caches are indexed
  by radix tree node, but for 2 million cached inodes that would mean a
  density of 1 inode per radix tree node, which for a system with 16M
  inodes in the filsystems is an impossibly low density.  The worst I've
  seen in a production system like kernel.org is about 20-25% density,
  which would mean about 150-200k radix tree nodes for that many inodes.
  So it's not the inode cache.

  So I looked up what the iint_cache was.  It appears to used for
  storing per-inode IMA information, and uses a radix tree for indexing.
  It uses the *address* of the struct inode as the indexing key.  That
  means the key space is extremely sparse - for XFS the struct inode
  addresses are approximately 1000 bytes apart, which means the closest
  the radix tree index keys get is ~1000.  Which means that there is a
  single entry per radix tree leaf node, so the radix tree is using
  roughly 550 bytes for every 120byte structure being cached.  For the
  above example, it's probably wasting close to 1GB of RAM...."

Reported-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:17 -07:00
Christoph Hellwig be148247cf fs: take dcache_lock inside __d_path
All callers take dcache_lock just around the call to __d_path, so
take the lock into it in preparation of getting rid of dcache_lock.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:12 -04:00
Christoph Hellwig 85fe4025c6 fs: do not assign default i_ino in new_inode
Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves.  For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:11 -04:00
Linus Torvalds 092e0e7e52 Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek
2010-10-22 10:52:56 -07:00
Stephen Rothwell f0d3d9894e selinux: include vmalloc.h for vmalloc_user
Include vmalloc.h for vmalloc_user (fixes ppc build warning).
Acked-by: Eric Paris <eparis@redhat.com>

Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:13:01 +11:00
Eric Paris 845ca30fe9 selinux: implement mmap on /selinux/policy
/selinux/policy allows a user to copy the policy back out of the kernel.
This patch allows userspace to actually mmap that file and use it directly.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:59 +11:00
Eric Paris cee74f47a6 SELinux: allow userspace to read policy back out of the kernel
There is interest in being able to see what the actual policy is that was
loaded into the kernel.  The patch creates a new selinuxfs file
/selinux/policy which can be read by userspace.  The actual policy that is
loaded into the kernel will be written back out to userspace.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:58 +11:00
Eric Paris 00d85c83ac SELinux: drop useless (and incorrect) AVTAB_MAX_SIZE
AVTAB_MAX_SIZE was a define which was supposed to be used in userspace to
define a maximally sized avtab when userspace wasn't sure how big of a table
it needed.  It doesn't make sense in the kernel since we always know our table
sizes.  The only place it is used we have a more appropiately named define
called AVTAB_MAX_HASH_BUCKETS, use that instead.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:57 +11:00
Eric Paris 4419aae1f4 SELinux: deterministic ordering of range transition rules
Range transition rules are placed in the hash table in an (almost)
arbitrary order.  This patch inserts them in a fixed order to make policy
retrival more predictable.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:56 +11:00
Eric Paris d5630b9d27 security: secid_to_secctx returns len when data is NULL
With the (long ago) interface change to have the secid_to_secctx functions
do the string allocation instead of having the caller do the allocation we
lost the ability to query the security server for the length of the
upcoming string.  The SECMARK code would like to allocate a netlink skb
with enough length to hold the string but it is just too unclean to do the
string allocation twice or to do the allocation the first time and hold
onto the string and slen.  This patch adds the ability to call
security_secid_to_secctx() with a NULL data pointer and it will just set
the slen pointer.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:50 +11:00
Eric Paris 2606fd1fa5 secmark: make secmark object handling generic
Right now secmark has lots of direct selinux calls.  Use all LSM calls and
remove all SELinux specific knowledge.  The only SELinux specific knowledge
we leave is the mode.  The only point is to make sure that other LSMs at
least test this generic code before they assume it works.  (They may also
have to make changes if they do not represent labels as strings)

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Paul Moore <paul.moore@hp.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:48 +11:00
John Johansen 3ed02ada2a AppArmor: Ensure the size of the copy is < the buffer allocated to hold it
Actually I think in this case the appropriate thing to do is to BUG as there
is currently a case (remove) where the alloc_size needs to be larger than
the copy_size, and if copy_size is ever greater than alloc_size there is
a mistake in the caller code.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:46 +11:00
Tetsuo Handa 9f1c1d426b TOMOYO: Print URL information before panic().
Configuration files for TOMOYO 2.3 are not compatible with TOMOYO 2.2.
But current panic() message is too unfriendly and is confusing users.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:45 +11:00
KOSAKI Motohiro b0ae198113 security: remove unused parameter from security_task_setscheduler()
All security modules shouldn't change sched_param parameter of
security_task_setscheduler().  This is not only meaningless, but also
make a harmful result if caller pass a static variable.

This patch remove policy and sched_param parameter from
security_task_setscheduler() becuase none of security module is
using it.

Cc: James Morris <jmorris@namei.org>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:44 +11:00
KaiGai Kohei 36f7f28416 selinux: fix up style problem on /selinux/status
This patch fixes up coding-style problem at this commit:

 4f27a7d49789b04404eca26ccde5f527231d01d5
 selinux: fast status update interface (/selinux/status)

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:41 +11:00
matt mooney 8b0c543e5c selinux: change to new flag variable
Replace EXTRA_CFLAGS with ccflags-y.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:40 +11:00
Paul Gortmaker 60272da034 selinux: really fix dependency causing parallel compile failure.
While the previous change to the selinux Makefile reduced the window
significantly for this failure, it is still possible to see a compile
failure where cpp starts processing selinux files before the auto
generated flask.h file is completed.  This is easily reproduced by
adding the following temporary change to expose the issue everytime:

-      cmd_flask = scripts/selinux/genheaders/genheaders ...
+      cmd_flask = sleep 30 ; scripts/selinux/genheaders/genheaders ...

This failure happens because the creation of the object files in the ss
subdir also depends on flask.h.  So simply incorporate them into the
parent Makefile, as the ss/Makefile really doesn't do anything unique.

With this change, compiling of all selinux files is dependent on
completion of the header file generation, and this test case with
the "sleep 30" now confirms it is functioning as expected.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:39 +11:00
Paul Gortmaker ceba72a68d selinux: fix parallel compile error
Selinux has an autogenerated file, "flask.h" which is included by
two other selinux files.  The current makefile has a single dependency
on the first object file in the selinux-y list, assuming that will get
flask.h generated before anyone looks for it, but that assumption breaks
down in a "make -jN" situation and you get:

   selinux/selinuxfs.c:35: fatal error: flask.h: No such file or directory
   compilation terminated.
   remake[9]: *** [security/selinux/selinuxfs.o] Error 1

Since flask.h is included by security.h which in turn is included
nearly everywhere, make the dependency apply to all of the selinux-y
list of objs.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:38 +11:00
KaiGai Kohei 1190416725 selinux: fast status update interface (/selinux/status)
This patch provides a new /selinux/status entry which allows applications
read-only mmap(2).
This region reflects selinux_kernel_status structure in kernel space.
  struct selinux_kernel_status
  {
          u32     length;         /* length of this structure */
          u32     sequence;       /* sequence number of seqlock logic */
          u32     enforcing;      /* current setting of enforcing mode */
          u32     policyload;     /* times of policy reloaded */
          u32     deny_unknown;   /* current setting of deny_unknown */
  };

When userspace object manager caches access control decisions provided
by SELinux, it needs to invalidate the cache on policy reload and setenforce
to keep consistency.
However, the applications need to check the kernel state for each accesses
on userspace avc, or launch a background worker process.
In heuristic, frequency of invalidation is much less than frequency of
making access control decision, so it is annoying to invoke a system call
to check we don't need to invalidate the userspace cache.
If we can use a background worker thread, it allows to receive invalidation
messages from the kernel. But it requires us an invasive coding toward the
base application in some cases; E.g, when we provide a feature performing
with SELinux as a plugin module, it is unwelcome manner to launch its own
worker thread from the module.

If we could map /selinux/status to process memory space, application can
know updates of selinux status; policy reload or setenforce.

A typical application checks selinux_kernel_status::sequence when it tries
to reference userspace avc. If it was changed from the last time when it
checked userspace avc, it means something was updated in the kernel space.
Then, the application can reset userspace avc or update current enforcing
mode, without any system call invocations.
This sequence number is updated according to the seqlock logic, so we need
to wait for a while if it is odd number.

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Eric Paris <eparis@redhat.com>
--
 security/selinux/include/security.h |   21 ++++++
 security/selinux/selinuxfs.c        |   56 +++++++++++++++
 security/selinux/ss/Makefile        |    2 +-
 security/selinux/ss/services.c      |    3 +
 security/selinux/ss/status.c        |  129 +++++++++++++++++++++++++++++++++++
 5 files changed, 210 insertions(+), 1 deletions(-)
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:36 +11:00
Yong Zhang 4b04a7cfc5 .gitignore: ignore apparmor/rlim_names.h
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:35 +11:00
Tetsuo Handa 065d78a060 LSM: Fix security_module_enable() error.
We can set default LSM module to DAC (which means "enable no LSM module").
If default LSM module was set to DAC, security_module_enable() must return 0
unless overridden via boot time parameter.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:34 +11:00
Eric Paris daa6d83a28 selinux: type_bounds_sanity_check has a meaningless variable declaration
type is not used at all, stop declaring and assigning it.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:33 +11:00
Dan Carpenter 68eda8f590 tomoyo: cleanup. don't store bogus pointer
If domain is NULL then &domain->list is a bogus address.  Let's leave
head->r.domain NULL instead of saving an unusable pointer.

This is just a cleanup.  The current code always checks head->r.eof
before dereferencing head->r.domain.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2010-10-21 10:12:32 +11:00
Arnd Bergmann 6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Ben Hutchings c8da96e87d TOMOYO: Don't abuse sys_getpid(), sys_getppid()
System call entry functions sys_*() are never to be called from
general kernel code.  The fact that they aren't declared in header
files should have been a clue.  These functions also don't exist on
Alpha since it has sys_getxpid() instead.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2010-09-27 10:53:18 +10:00
David Howells 3d96406c7d KEYS: Fix bug in keyctl_session_to_parent() if parent has no session keyring
Fix a bug in keyctl_session_to_parent() whereby it tries to check the ownership
of the parent process's session keyring whether or not the parent has a session
keyring [CVE-2010-2960].

This results in the following oops:

  BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0
  IP: [<ffffffff811ae4dd>] keyctl_session_to_parent+0x251/0x443
  ...
  Call Trace:
   [<ffffffff811ae2f3>] ? keyctl_session_to_parent+0x67/0x443
   [<ffffffff8109d286>] ? __do_fault+0x24b/0x3d0
   [<ffffffff811af98c>] sys_keyctl+0xb4/0xb8
   [<ffffffff81001eab>] system_call_fastpath+0x16/0x1b

if the parent process has no session keyring.

If the system is using pam_keyinit then it mostly protected against this as all
processes derived from a login will have inherited the session keyring created
by pam_keyinit during the log in procedure.

To test this, pam_keyinit calls need to be commented out in /etc/pam.d/.

Reported-by: Tavis Ormandy <taviso@cmpxchg8b.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Tavis Ormandy <taviso@cmpxchg8b.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-10 07:30:00 -07:00
David Howells 9d1ac65a96 KEYS: Fix RCU no-lock warning in keyctl_session_to_parent()
There's an protected access to the parent process's credentials in the middle
of keyctl_session_to_parent().  This results in the following RCU warning:

  ===================================================
  [ INFO: suspicious rcu_dereference_check() usage. ]
  ---------------------------------------------------
  security/keys/keyctl.c:1291 invoked rcu_dereference_check() without protection!

  other info that might help us debug this:

  rcu_scheduler_active = 1, debug_locks = 0
  1 lock held by keyctl-session-/2137:
   #0:  (tasklist_lock){.+.+..}, at: [<ffffffff811ae2ec>] keyctl_session_to_parent+0x60/0x236

  stack backtrace:
  Pid: 2137, comm: keyctl-session- Not tainted 2.6.36-rc2-cachefs+ #1
  Call Trace:
   [<ffffffff8105606a>] lockdep_rcu_dereference+0xaa/0xb3
   [<ffffffff811ae379>] keyctl_session_to_parent+0xed/0x236
   [<ffffffff811af77e>] sys_keyctl+0xb4/0xb6
   [<ffffffff81001eab>] system_call_fastpath+0x16/0x1b

The code should take the RCU read lock to make sure the parents credentials
don't go away, even though it's holding a spinlock and has IRQ disabled.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-10 07:30:00 -07:00
Mimi Zohar e950598d43 ima: always maintain counters
commit 8262bb85da allocated the inode integrity struct (iint) before any
inodes were created. Only after IMA was initialized in late_initcall were
the counters updated. This patch updates the counters, whether or not IMA
has been initialized, to resolve 'imbalance' messages.

This patch fixes the bug as reported in bugzilla: 15673.  When the i915
is builtin, the ring_buffer is initialized before IMA, causing the
imbalance message on suspend.

Reported-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Tested-by: Thomas Meyer <thomas@m3y3r.de>
Tested-by: David Safford<safford@watson.ibm.com>
Cc: Stable Kernel <stable@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
2010-09-08 09:51:41 +10:00
John Johansen 999b4f0aa2 AppArmor: Fix locking from removal of profile namespace
The locking for profile namespace removal is wrong, when removing a
profile namespace, it needs to be removed from its parent's list.
Lock the parent of namespace list instead of the namespace being removed.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-09-08 09:19:34 +10:00
John Johansen 04ccd53f09 AppArmor: Fix splitting an fqname into separate namespace and profile names
As per Dan Carpenter <error27@gmail.com>
  If we have a ns name without a following profile then in the original
  code it did "*ns_name = &name[1];".  "name" is NULL so "*ns_name" is
  0x1.  That isn't useful and could cause an oops when this function is
  called from aa_remove_profiles().

Beyond this the assignment of the namespace name was wrong in the case
where the profile name was provided as it was being set to &name[1]
after name  = skip_spaces(split + 1);

Move the ns_name assignment before updating name for the split and
also add skip_spaces, making the interface more robust.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-09-08 09:19:31 +10:00
John Johansen 3a2dc8382a AppArmor: Fix security_task_setrlimit logic for 2.6.36 changes
2.6.36 introduced the abilitiy to specify the task that is having its
rlimits set.  Update mediation to ensure that confined tasks can only
set their own group_leader as expected by current policy.

Add TODO note about extending policy to support setting other tasks
rlimits.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-09-08 09:19:29 +10:00
John Johansen e819ff519b AppArmor: Drop hack to remove appended " (deleted)" string
The 2.6.36 kernel has refactored __d_path() so that it no longer appends
" (deleted)" to unlinked paths.  So drop the hack that was used to detect
and remove the appended string.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-09-08 09:19:24 +10:00
Linus Torvalds 145c3ae46b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  fs: brlock vfsmount_lock
  fs: scale files_lock
  lglock: introduce special lglock and brlock spin locks
  tty: fix fu_list abuse
  fs: cleanup files_lock locking
  fs: remove extra lookup in __lookup_hash
  fs: fs_struct rwlock to spinlock
  apparmor: use task path helpers
  fs: dentry allocation consolidation
  fs: fix do_lookup false negative
  mbcache: Limit the maximum number of cache entries
  hostfs ->follow_link() braino
  hostfs: dumb (and usually harmless) tpyo - strncpy instead of strlcpy
  remove SWRITE* I/O types
  kill BH_Ordered flag
  vfs: update ctime when changing the file's permission by setfacl
  cramfs: only unlock new inodes
  fix reiserfs_evict_inode end_writeback second call
2010-08-18 09:35:08 -07:00
Nick Piggin d996b62a8d tty: fix fu_list abuse
tty: fix fu_list abuse

tty code abuses fu_list, which causes a bug in remount,ro handling.

If a tty device node is opened on a filesystem, then the last link to the inode
removed, the filesystem will be allowed to be remounted readonly. This is
because fs_may_remount_ro does not find the 0 link tty inode on the file sb
list (because the tty code incorrectly removed it to use for its own purpose).
This can result in a filesystem with errors after it is marked "clean".

Taking idea from Christoph's initial patch, allocate a tty private struct
at file->private_data and put our required list fields in there, linking
file and tty. This makes tty nodes behave the same way as other device nodes
and avoid meddling with the vfs, and avoids this bug.

The error handling is not trivial in the tty code, so for this bugfix, I take
the simple approach of using __GFP_NOFAIL and don't worry about memory errors.
This is not a problem because our allocator doesn't fail small allocs as a rule
anyway. So proper error handling is left as an exercise for tty hackers.

[ Arguably filesystem's device inode would ideally be divorced from the
driver's pseudo inode when it is opened, but in practice it's not clear whether
that will ever be worth implementing. ]

Cc: linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:47 -04:00
Nick Piggin ee2ffa0dfd fs: cleanup files_lock locking
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 <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:47 -04:00
Nick Piggin 44672e4fbd apparmor: use task path helpers
apparmor: use task path helpers

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:46 -04:00
Linus Torvalds 3b89f56783 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  AppArmor: fix task_setrlimit prototype
2010-08-17 18:37:03 -07:00
David Howells d7627467b7 Make do_execve() take a const filename pointer
Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:

arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type

This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to.  This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel().  A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().

do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.

Further kernel_execve() and sys_execve() need to be changed to match.

This has been test built on x86_64, frv, arm and mips.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-17 18:07:43 -07:00