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* IMA: drop refcnt from ima_iint_cache since it isn't neededEric Paris2010-10-261-3/+1
| | | | | | | | | | | | | 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: move read counter into struct inodeEric Paris2010-10-261-2/+1
| | | | | | | | | | | | | | | | | | | | | 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: use i_writecount rather than a private counterEric Paris2010-10-261-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* IMA: use inode->i_lock to protect read and write countersEric Paris2010-10-261-0/+1
| | | | | | | | | | 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>
* IMA: convert internal flags from long to charEric Paris2010-10-261-2/+2
| | | | | | | | | | 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>
* IMA: use unsigned int instead of long for countersEric Paris2010-10-261-2/+2
| | | | | | | | | | | 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>
* IMA: drop the inode opencount since it isn't needed for operationEric Paris2010-10-261-1/+0
| | | | | | | | | | | | 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>
* IMA: use rbtree instead of radix tree for inode information cacheEric Paris2010-10-261-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ima: always maintain countersMimi Zohar2010-09-081-0/+1
| | | | | | | | | | | | | | | | | | 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>
* ima: handle multiple rules per writeEric Paris2010-04-211-1/+1
| | | | | | | | | | | | | | | Currently IMA will only accept one rule per write(). This patch allows IMA to accept writes which contain multiple rules but only processes one rule per write. \n is used as the delimiter between rules. IMA will return a short write indicating that it only accepted up to the first \n. This allows simple userspace utilities like cat to be used to load an IMA policy instead of needing a special userspace utility that understood 'one write per rule' Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* ima: rename PATH_CHECK to FILE_CHECKMimi Zohar2010-02-071-1/+1
| | | | | | | | | | With the movement of the ima hooks functions were renamed from *path* to *file* since they always deal with struct file. This patch renames some of the ima internal flags to make them consistent with the rest of the code. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ima: initialize ima before inodes can be allocatedEric Paris2010-02-071-1/+0
| | | | | | | | | | | | | | ima wants to create an inode information struct (iint) when inodes are allocated. This means that at least the part of ima which does this allocation (the allocation is filled with information later) should before any inodes are created. To accomplish this we split the ima initialization routine placing the kmem cache allocator inside a security_initcall() function. Since this makes use of radix trees we also need to make sure that is initialized before security_initcall(). Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ima: call ima_inode_free ima_inode_freeEric Paris2009-12-161-1/+0
| | | | | | | | | | | | ima_inode_free() has some funky #define just to confuse the crap out of me. void ima_iint_delete(struct inode *inode) and then things actually call ima_inode_free() and nothing calls ima_iint_delete(). Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* IMA: clean up the IMA counts updating codeEric Paris2009-12-161-1/+0
| | | | | | | | | We currently have a lot of duplicated code around ima file counts. Clean that all up. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ima: only insert at inode creation timeEric Paris2009-12-161-1/+0
| | | | | | | | | | | iints are supposed to be allocated when an inode is allocated (during security_inode_alloc()) But we have code which will attempt to allocate an iint during measurement calls. If we couldn't allocate the iint and we cared, we should have died during security_inode_alloc(). Not make the code more complex and less efficient. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* integrity: audit updateMimi Zohar2009-02-121-1/+1
| | | | | | | | | | | | Based on discussions on linux-audit, as per Steve Grubb's request http://lkml.org/lkml/2009/2/6/269, the following changes were made: - forced audit result to be either 0 or 1. - made template names const - Added new stand-alone message type: AUDIT_INTEGRITY_RULE Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* Integrity: IMA file free imbalanceMimi Zohar2009-02-061-0/+2
| | | | | | | | | | | | | | | | | | | | | The number of calls to ima_path_check()/ima_file_free() should be balanced. An extra call to fput(), indicates the file could have been accessed without first being measured. Although f_count is incremented/decremented in places other than fget/fput, like fget_light/fput_light and get_file, the current task must already hold a file refcnt. The call to __fput() is delayed until the refcnt becomes 0, resulting in ima_file_free() flagging any changes. - add hook to increment opencount for IPC shared memory(SYSV), shmat files, and /dev/zero - moved NULL iint test in opencount_get() Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* integrity: IMA policyMimi Zohar2009-02-061-0/+24
| | | | | | | | | | Support for a user loadable policy through securityfs with support for LSM specific policy data. - free invalid rule in ima_parse_add_rule() Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* integrity: IMA displayMimi Zohar2009-02-061-0/+5
| | | | | | | | | Make the measurement lists available through securityfs. - removed test for NULL return code from securityfs_create_file/dir Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* integrity: IMA as an integrity service providerMimi Zohar2009-02-061-0/+135
IMA provides hardware (TPM) based measurement and attestation for file measurements. As the Trusted Computing (TPM) model requires, IMA measures all files before they are accessed in any way (on the integrity_bprm_check, integrity_path_check and integrity_file_mmap hooks), and commits the measurements to the TPM. Once added to the TPM, measurements can not be removed. In addition, IMA maintains a list of these file measurements, which can be used to validate the aggregate value stored in the TPM. The TPM can sign these measurements, and thus the system can prove, to itself and to a third party, the system's integrity in a way that cannot be circumvented by malicious or compromised software. - alloc ima_template_entry before calling ima_store_template() - log ima_add_boot_aggregate() failure - removed unused IMA_TEMPLATE_NAME_LEN - replaced hard coded string length with #define name Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>