kernel/security/integrity/ima/ima_iint.c, branch linux-rolling-stable

lsm: add the inode_free_security_rcu() LSM implementation hook

2024-10-04T14:33:42Z

commit 63dff3e48871b0583be5032ff8fb7260c349a18c upstream. The LSM framework has an existing inode_free_security() hook which is used by LSMs that manage state associated with an inode, but due to the use of RCU to protect the inode, special care must be taken to ensure that the LSMs do not fully release the inode state until it is safe from a RCU perspective. This patch implements a new inode_free_security_rcu() implementation hook which is called when it is safe to free the LSM's internal inode state. Unfortunately, this new hook does not have access to the inode itself as it may already be released, so the existing inode_free_security() hook is retained for those LSMs which require access to the inode. Cc: stable@vger.kernel.org Reported-by: syzbot+5446fbf332b0602ede0b@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/00000000000076ba3b0617f65cc8@google.com Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

ima: Move file-change detection variables into new structure

2024-04-09T21:14:57Z

Move all the variables used for file change detection into a structure that can be used by IMA and EVM. Implement an inline function for storing the identification of an inode and one for detecting changes to an inode based on this new structure. Co-developed-by: Mimi Zohar Signed-off-by: Stefan Berger Signed-off-by: Mimi Zohar

ima: Make it independent from 'integrity' LSM

2024-02-16T04:43:47Z

Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA own integrity metadata (ima_iint_cache structure, with IMA-specific fields from the integrity_iint_cache structure), and by managing it directly from the 'ima' LSM. Create ima_iint.c and introduce the same integrity metadata management functions found in iint.c (renamed with ima_). However, instead of putting metadata in an rbtree, reserve space from IMA in the inode security blob for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint() primitives to store/retrieve that pointer. This improves search time from logarithmic to constant. Consequently, don't include the inode pointer as field in the ima_iint_cache structure, since the association with the inode is clear. Since the inode field is missing in ima_iint_cache, pass the extra inode parameter to ima_get_verity_digest(). Prefer storing the pointer instead of the entire ima_iint_cache structure, to avoid too much memory pressure. Use the same mechanism as before, a cache named ima_iint_cache (renamed from iint_cache), to quickly allocate a new ima_iint_cache structure when requested by the IMA policy. Create the new ima_iint_cache in ima_iintcache_init(), called by init_ima_lsm(), during the initialization of the 'ima' LSM. And, register ima_inode_free_security() to free the ima_iint_cache structure, if exists. Replace integrity_iint_cache with ima_iint_cache in various places of the IMA code. Also, replace integrity_inode_get() and integrity_iint_find(), respectively with ima_inode_get() and ima_iint_find(). Finally, move the remaining IMA-specific flags to security/integrity/ima/ima.h, since they are now unnecessary in the common integrity layer. Signed-off-by: Roberto Sassu Reviewed-by: Casey Schaufler Reviewed-by: Stefan Berger Reviewed-by: Mimi Zohar Acked-by: Mimi Zohar Signed-off-by: Paul Moore

integrity: move ima inode integrity data management

2011-07-18T16:29:38Z

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 Acked-by: Serge Hallyn

IMA: remove IMA imbalance checking

2011-02-10T12:51:44Z

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 Acked-by: Eric Paris

IMA: maintain i_readcount in the VFS layer

2011-02-10T12:51:44Z

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 Acked-by: Eric Paris

IMA: convert i_readcount to atomic

2011-02-10T12:51:43Z

Convert the inode's i_readcount from an unsigned int to atomic. Signed-off-by: Mimi Zohar Acked-by: Eric Paris

IMA: explicit IMA i_flag to remove global lock on inode_delete

2010-10-26T18:37:19Z

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 Acked-by: Mimi Zohar Signed-off-by: Linus Torvalds

IMA: drop refcnt from ima_iint_cache since it isn't needed

2010-10-26T18:37:19Z

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 Acked-by: Mimi Zohar Signed-off-by: Linus Torvalds

IMA: move read counter into struct inode

2010-10-26T18:37:18Z

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 Acked-by: Mimi Zohar Signed-off-by: Linus Torvalds