The kernel syslog contains debugging information that is often useful
during exploitation of other vulnerabilities, such as kernel heap
addresses. Rather than futilely attempt to sanitize hundreds (or
thousands) of printk statements and simultaneously cripple useful
debugging functionality, it is far simpler to create an option that
prevents unprivileged users from reading the syslog.
This patch, loosely based on grsecurity's GRKERNSEC_DMESG, creates the
dmesg_restrict sysctl. When set to "0", the default, no restrictions are
enforced. When set to "1", only users with CAP_SYS_ADMIN can read the
kernel syslog via dmesg(8) or other mechanisms.
[akpm@linux-foundation.org: explain the config option in kernel.txt]
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Eugene Teo <eugeneteo@kernel.org>
Acked-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
set_init_cxt() allocted sizeof(struct aa_task_cxt) bytes for cxt,
if register_security() failed, it will cause memory leak.
Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
policy->name is a substring of policy->hname, if prefix is not NULL, it will
allocted strlen(prefix) + strlen(name) + 3 bytes to policy->hname in policy_init().
use kzfree(ns->base.name) will casue memory leak if alloc_namespace() failed.
Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Fix an incorrect error check that returns 1 for error instead of the
expected error code.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* '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()
...
* 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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
* '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
/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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
* '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
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>
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>
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>
After rlimits tree was merged we get the following errors:
security/apparmor/lsm.c:663:2: warning: initialization from incompatible pointer type
It is because AppArmor was merged in the meantime, but uses the old
prototype. So fix it by adding struct task_struct as a first parameter
of apparmor_task_setrlimit.
NOTE that this is ONLY a compilation warning fix (and crashes caused
by that). It needs proper handling in AppArmor depending on who is the
'task'.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
* 'params' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (22 commits)
param: don't deref arg in __same_type() checks
param: update drivers/acpi/debug.c to new scheme
param: use module_param in drivers/message/fusion/mptbase.c
ide: use module_param_named rather than module_param_call
param: update drivers/char/ipmi/ipmi_watchdog.c to new scheme
param: lock if_sdio's lbs_helper_name and lbs_fw_name against sysfs changes.
param: lock myri10ge_fw_name against sysfs changes.
param: simple locking for sysfs-writable charp parameters
param: remove unnecessary writable charp
param: add kerneldoc to moduleparam.h
param: locking for kernel parameters
param: make param sections const.
param: use free hook for charp (fix leak of charp parameters)
param: add a free hook to kernel_param_ops.
param: silence .init.text references from param ops
Add param ops struct for hvc_iucv driver.
nfs: update for module_param_named API change
AppArmor: update for module_param_named API change
param: use ops in struct kernel_param, rather than get and set fns directly
param: move the EXPORT_SYMBOL to after the definitions.
...
Add a dummy printk function for the maintenance of unused printks through gcc
format checking, and also so that side-effect checking is maintained too.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes these build errors:
security/apparmor/lsm.c:701: error: 'param_ops_aabool' undeclared here (not in a function)
security/apparmor/lsm.c:721: error: 'param_ops_aalockpolicy' undeclared here (not in a function)
security/apparmor/lsm.c:729: error: 'param_ops_aauint' undeclared here (not in a function)
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux:
unistd: add __NR_prlimit64 syscall numbers
rlimits: implement prlimit64 syscall
rlimits: switch more rlimit syscalls to do_prlimit
rlimits: redo do_setrlimit to more generic do_prlimit
rlimits: add rlimit64 structure
rlimits: do security check under task_lock
rlimits: allow setrlimit to non-current tasks
rlimits: split sys_setrlimit
rlimits: selinux, do rlimits changes under task_lock
rlimits: make sure ->rlim_max never grows in sys_setrlimit
rlimits: add task_struct to update_rlimit_cpu
rlimits: security, add task_struct to setrlimit
Fix up various system call number conflicts. We not only added fanotify
system calls in the meantime, but asm-generic/unistd.h added a wait4
along with a range of reserved per-architecture system calls.
* '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.
Fix build error caused by a stale security/selinux/av_permissions.h in the $(src)
directory which will override a more recent version in $(obj) that is it
appears to strike only when building with a separate object directory.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
request_key() should return -ENOKEY if the key it constructs has been
negatively instantiated.
Without this, request_key() can return an unusable key to its caller,
and if the caller then does key_validate() that won't catch the problem.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SECURITY_APPARMOR should depend on NET since AUDIT needs
(depends on) NET.
Fixes 70-80 errors that occur when CONFIG_NET is not enabled,
but APPARMOR selects AUDIT without qualification. E.g.:
audit.c:(.text+0x33361): undefined reference to `netlink_unicast'
(.text+0x333df): undefined reference to `netlink_unicast'
audit.c:(.text+0x3341d): undefined reference to `skb_queue_tail'
audit.c:(.text+0x33424): undefined reference to `kfree_skb'
audit.c:(.text+0x334cb): undefined reference to `kfree_skb'
audit.c:(.text+0x33597): undefined reference to `skb_put'
audit.c:(.text+0x3369b): undefined reference to `__alloc_skb'
audit.c:(.text+0x336d7): undefined reference to `kfree_skb'
(.text+0x3374c): undefined reference to `__alloc_skb'
auditfilter.c:(.text+0x35305): undefined reference to `skb_queue_tail'
lsm_audit.c:(.text+0x2873): undefined reference to `init_net'
lsm_audit.c:(.text+0x2878): undefined reference to `dev_get_by_index'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Current selinux policy can have over 3000 types. The type_attr_map in
policy is an array sized by the number of types times sizeof(struct ebitmap)
(12 on x86_64). Basic math tells us the array is going to be of length
3000 x 12 = 36,000 bytes. The largest 'safe' allocation on a long running
system is 16k. Most of the time a 32k allocation will work. But on long
running systems a 64k allocation (what we need) can fail quite regularly.
In order to deal with this I am converting the type_attr_map to use
flex_arrays. Let the library code deal with breaking this into PAGE_SIZE
pieces.
-v2
rework some of the if(!obj) BUG() to be BUG_ON(!obj)
drop flex_array_put() calls and just use a _get() object directly
-v3
make apply to James' tree (drop the policydb_write changes)
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Kconfig and Makefiles to enable configuration and building of AppArmor.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Commit c9e69318 "TOMOYO: Allow wildcard for execute permission." changed execute
permission and domainname to accept wildcards. But tomoyo_find_next_domain()
was using pathname passed to execve() rather than pathname specified by the
execute permission. As a result, processes were not able to transit to domains
which contain wildcards in their domainnames.
This patch passes pathname specified by the execute permission back to
tomoyo_find_next_domain() so that processes can transit to domains which
contain wildcards in their domainnames.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
Remove extraneous path_truncate arguments from the AppArmor hook,
as they've been removed from the LSM API.
Signed-off-by: James Morris <jmorris@namei.org>
The basic routines and defines for AppArmor policy. AppArmor policy
is defined by a few basic components.
profiles - the basic unit of confinement contain all the information
to enforce policy on a task
Profiles tend to be named after an executable that they
will attach to but this is not required.
namespaces - a container for a set of profiles that will be used
during attachment and transitions between profiles.
sids - which provide a unique id for each profile
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
AppArmor policy is loaded in a platform independent flattened binary
stream. Verify and unpack the data converting it to the internal
format needed for enforcement.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
ipc:
AppArmor ipc is currently limited to mediation done by file mediation
and basic ptrace tests. Improved mediation is a wip.
rlimits:
AppArmor provides basic abilities to set and control rlimits at
a per profile level. Only resources specified in a profile are controled
or set. AppArmor rules set the hard limit to a value <= to the current
hard limit (ie. they can not currently raise hard limits), and if
necessary will lower the soft limit to the new hard limit value.
AppArmor does not track resource limits to reset them when a profile
is left so that children processes inherit the limits set by the
parent even if they are not confined by the same profile.
Capabilities: AppArmor provides a per profile mask of capabilities,
that will further restrict.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
AppArmor hooks to interface with the LSM, module parameters and module
initialization.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Kconfig and Makefiles to enable configuration and building of AppArmor.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
AppArmor routines for controling domain transitions, which can occur at
exec or through self directed change_profile/change_hat calls.
Unconfined tasks are checked at exec against the profiles in the confining
profile namespace to determine if a profile should be attached to the task.
Confined tasks execs are controlled by the profile which provides rules
determining which execs are allowed and if so which profiles should be
transitioned to.
Self directed domain transitions allow a task to request transition
to a given profile. If the transition is allowed then the profile will
be applied, either immeditately or at exec time depending on the request.
Immeditate self directed transitions have several security limitations
but have uses in setting up stub transition profiles and other limited
cases.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
AppArmor does files enforcement via pathname matching. Matching is done
at file open using a dfa match engine. Permission is against the final
file object not parent directories, ie. the traversal of directories
as part of the file match is implicitly allowed. In the case of nonexistant
files (creation) permissions are checked against the target file not the
directory. eg. In case of creating the file /dir/new, permissions are
checked against the match /dir/new not against /dir/.
The permissions for matches are currently stored in the dfa accept table,
but this will change to allow for dfa reuse and also to allow for sharing
of wider accept states.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
The /proc/<pid>/attr/* interface is used for process introspection and
commands. While the apparmorfs interface is used for global introspection
and loading and removing policy.
The interface currently only contains the files necessary for loading
policy, and will be extended in the future to include sysfs style
single per file introspection inteface.
The old AppArmor 2.4 interface files have been removed into a compatibility
patch, that distros can use to maintain backwards compatibility.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
A basic dfa matching engine based off the dfa engine in the Dragon
Book. It uses simple row comb compression with a check field.
This allows AppArmor to do pattern matching in linear time, and also
avoids stack issues that an nfa based engine may have. The dfa
engine uses a byte based comparison, with all values being valid.
Any potential character encoding are handled user side when the dfa
tables are created. By convention AppArmor uses \0 to separate two
dependent path matches since \0 is not a valid path character
(this is done in the link permission check).
The dfa tables are generated in user space and are verified at load
time to be internally consistent.
There are several future improvements planned for the dfa engine:
* The dfa engine may be converted to a hybrid nfa-dfa engine, with
a fixed size limited stack. This would allow for size time
tradeoffs, by inserting limited nfa states to help control
state explosion that can occur with dfas.
* The dfa engine may pickup the ability to do limited dynamic
variable matching, instead of fixing all variables at policy
load time.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
AppArmor contexts attach profiles and state to tasks, files, etc. when
a direct profile reference is not sufficient.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Update lsm_audit for AppArmor specific data, and add the core routines for
AppArmor uses for auditing.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Miscellaneous functions and defines needed by AppArmor, including
the base path resolution routines.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Commit d74725b9 "TOMOYO: Use callback for updating entries." broke
tomoyo_domain_quota_is_ok() by counting deleted entries. It needs to
count non-deleted entries.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
execmod "could" show up on non regular files and non chr files. The current
implementation would actually make these checks against non-existant bits
since the code assumes the execmod permission is same for all file types.
To make this line up for chr files we had to define execute_no_trans and
entrypoint permissions. These permissions are unreachable and only existed
to to make FILE__EXECMOD and CHR_FILE__EXECMOD the same. This patch drops
those needless perms as well.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
kernel can dynamically remap perms. Drop the open lookup table and put open
in the common file perms.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Currently there are a number of applications (nautilus being the main one) which
calls access() on files in order to determine how they should be displayed. It
is normal and expected that nautilus will want to see if files are executable
or if they are really read/write-able. access() should return the real
permission. SELinux policy checks are done in access() and can result in lots
of AVC denials as policy denies RWX on files which DAC allows. Currently
SELinux must dontaudit actual attempts to read/write/execute a file in
order to silence these messages (and not flood the logs.) But dontaudit rules
like that can hide real attacks. This patch addes a new common file
permission audit_access. This permission is special in that it is meaningless
and should never show up in an allow rule. Instead the only place this
permission has meaning is in a dontaudit rule like so:
dontaudit nautilus_t sbin_t:file audit_access
With such a rule if nautilus just checks access() we will still get denied and
thus userspace will still get the correct answer but we will not log the denial.
If nautilus attempted to actually perform one of the forbidden actions
(rather than just querying access(2) about it) we would still log a denial.
This type of dontaudit rule should be used sparingly, as it could be a
method for an attacker to probe the system permissions without detection.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
SELinux needs to pass the MAY_ACCESS flag so it can handle auditting
correctly. Presently the masking of MAY_* flags is done in the VFS. In
order to allow LSMs to decide what flags they care about and what flags
they don't just pass them all and the each LSM mask off what they don't
need. This patch should contain no functional changes to either the VFS or
any LSM.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Move the reading of ocontext type data out of policydb_read() in a separate
function ocontext_read()
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
move genfs read functionality out of policydb_read() and into a new
function called genfs_read()
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
hashtab_create() only returns NULL on allocation failures to -ENOMEM is
appropriate here.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
The original code always returned -1 (-EPERM) on error. The new code
returns either -ENOMEM, or -EINVAL or it propagates the error codes from
lower level functions next_entry() or hashtab_insert().
next_entry() returns -EINVAL.
hashtab_insert() returns -EINVAL, -EEXIST, or -ENOMEM.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
It's better to propagate the error code from avtab_init() instead of
returning -1 (-EPERM). It turns out that avtab_init() never fails so
this patch doesn't change how the code runs but it's still a clean up.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Originally cond_read_node() returned -1 (-EPERM) on errors which was
incorrect. Now it either propagates the error codes from lower level
functions next_entry() or cond_read_av_list() or it returns -ENOMEM or
-EINVAL.
next_entry() returns -EINVAL.
cond_read_av_list() returns -EINVAL or -ENOMEM.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
After this patch cond_read_av_list() no longer returns -1 for any
errors. It just propagates error code back from lower levels. Those can
either be -EINVAL or -ENOMEM.
I also modified cond_insertf() since cond_read_av_list() passes that as a
function pointer to avtab_read_item(). It isn't used anywhere else.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
These are passed back when the security module gets loaded.
The original code always returned -1 (-EPERM) on error but after this
patch it can return -EINVAL, or -ENOMEM or propagate the error code from
cond_read_node(). cond_read_node() still returns -1 all the time, but I
fix that in a later patch.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Linus Torvalds