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path: root/security/integrity/ima/ima_iint.c
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2011-07-18integrity: move ima inode integrity data managementMimi Zohar
Move the inode integrity data(iint) management up to the integrity directory in order to share the iint among the different integrity models. Changelog: - don't define MAX_DIGEST_SIZE - rename several globally visible 'ima_' prefixed functions, structs, locks, etc to 'integrity_' - replace '20' with SHA1_DIGEST_SIZE - reflect location change in appropriate Kconfig and Makefiles - remove unnecessary initialization of iint_initialized to 0 - rebased on current ima_iint.c - define integrity_iint_store/lock as static There should be no other functional changes. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2011-02-10IMA: remove IMA imbalance checkingMimi Zohar
Now that i_readcount is maintained by the VFS layer, remove the imbalance checking in IMA. Cleans up the IMA code nicely. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com>
2011-02-10IMA: maintain i_readcount in the VFS layerMimi Zohar
ima_counts_get() updated the readcount and invalidated the PCR, as necessary. Only update the i_readcount in the VFS layer. Move the PCR invalidation checks to ima_file_check(), where it belongs. Maintaining the i_readcount in the VFS layer, will allow other subsystems to use i_readcount. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com>
2011-02-10IMA: convert i_readcount to atomicMimi Zohar
Convert the inode's i_readcount from an unsigned int to atomic. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com>
2010-10-26IMA: explicit IMA i_flag to remove global lock on inode_deleteEric Paris
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>
2010-10-26IMA: drop refcnt from ima_iint_cache since it isn't neededEric Paris
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>
2010-10-26IMA: move read counter into struct inodeEric Paris
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>
2010-10-26IMA: use i_writecount rather than a private counterEric Paris
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>
2010-10-26IMA: use unsigned int instead of long for countersEric Paris
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>
2010-10-26IMA: drop the inode opencount since it isn't needed for operationEric Paris
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>
2010-10-26IMA: use rbtree instead of radix tree for inode information cacheEric Paris
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>
2010-09-08ima: always maintain countersMimi Zohar
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>
2010-05-21kref: remove kref_setNeilBrown
Of the three uses of kref_set in the kernel: One really should be kref_put as the code is letting go of a reference, Two really should be kref_init because the kref is being initialised. This suggests that making kref_set available encourages bad code. So fix the three uses and remove kref_set completely. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-06Merge branch 'master' into nextJames Morris
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-10security/ima: replace gcc specific __FUNCTION__ with __func__H Hartley Sweeten
As noted by checkpatch.pl, __func__ should be used instead of gcc specific __FUNCTION__. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-02-25security: fix error return path in ima_inode_allocXiaotian Feng
If radix_tree_preload is failed in ima_inode_alloc, we don't need radix_tree_preload_end because kernel is alread preempt enabled Signed-off-by: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-02-07ima: initialize ima before inodes can be allocatedEric Paris
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>
2009-12-16ima: call ima_inode_free ima_inode_freeEric Paris
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>
2009-12-16ima: only insert at inode creation timeEric Paris
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>
2009-12-16ima: valid return code from ima_inode_allocEric Paris
ima_inode_alloc returns 0 and 1, but the LSM hooks expects an errno. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-11-19ima: replace GFP_KERNEL with GFP_NOFSMimi Zohar
While running fsstress tests on the NFSv4 mounted ext3 and ext4 filesystem, the following call trace was generated on the nfs server machine. Replace GFP_KERNEL with GFP_NOFS in ima_iint_insert() to avoid a potential deadlock. ================================= [ INFO: inconsistent lock state ] 2.6.31-31.el6.x86_64 #1 --------------------------------- inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage. kswapd2/75 [HC0[0]:SC0[0]:HE1:SE1] takes: (jbd2_handle){+.+.?.}, at: [<ffffffff811edd5e>] jbd2_journal_start+0xfe/0x13f {RECLAIM_FS-ON-W} state was registered at: [<ffffffff81091e40>] mark_held_locks+0x65/0x99 [<ffffffff81091f31>] lockdep_trace_alloc+0xbd/0xf5 [<ffffffff81126fdd>] kmem_cache_alloc+0x40/0x185 [<ffffffff812344d7>] ima_iint_insert+0x3d/0xf1 [<ffffffff812345b0>] ima_inode_alloc+0x25/0x44 [<ffffffff811484ac>] inode_init_always+0xec/0x271 [<ffffffff81148682>] alloc_inode+0x51/0xa1 [<ffffffff81148700>] new_inode+0x2e/0x94 [<ffffffff811b2f08>] ext4_new_inode+0xb8/0xdc9 [<ffffffff811be611>] ext4_create+0xcf/0x175 [<ffffffff8113e2cd>] vfs_create+0x82/0xb8 [<ffffffff8113f337>] do_filp_open+0x32c/0x9ee [<ffffffff811309b9>] do_sys_open+0x6c/0x12c [<ffffffff81130adc>] sys_open+0x2e/0x44 [<ffffffff81011e42>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff irq event stamp: 90371 hardirqs last enabled at (90371): [<ffffffff8112708d>] kmem_cache_alloc+0xf0/0x185 hardirqs last disabled at (90370): [<ffffffff81127026>] kmem_cache_alloc+0x89/0x185 softirqs last enabled at (89492): [<ffffffff81068ecf>] __do_softirq+0x1bf/0x1eb softirqs last disabled at (89477): [<ffffffff8101312c>] call_softirq+0x1c/0x30 other info that might help us debug this: 2 locks held by kswapd2/75: #0: (shrinker_rwsem){++++..}, at: [<ffffffff810f98ba>] shrink_slab+0x44/0x177 #1: (&type->s_umount_key#25){++++..}, at: [<ffffffff811450ba>] Reported-by: Muni P. Beerakam <mbeeraka@in.ibm.com> Reported-by: Amit K. Arora <amitarora@in.ibm.com> Cc: stable@kernel.org Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-05-22IMA: Add __init notation to ima functionsEric Paris
A number of IMA functions only used during init are not marked with __init. Add those notations so they are freed automatically. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-23integrity: ima iint radix_tree_lookup locking fixMimi Zohar
Based on Andrew Morton's comments: - add missing locks around radix_tree_lookup in ima_iint_insert() Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-06Integrity: IMA file free imbalanceMimi Zohar
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>
2009-02-06integrity: IMA as an integrity service providerMimi Zohar
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>