kernel/linux.git/security/integrity/ima/ima_api.c, branch v3.18.100

ima: detect violations for mmaped files

2014-09-18T14:04:12+00:00

This patch fixes the detection of the 'open_writers' violation for mmaped files. before) an 'open_writers' violation is detected if the policy contains a rule with the criteria: func=FILE_CHECK mask=MAY_READ after) an 'open_writers' violation is detected if the current event matches one of the policy rules. With the old behaviour, the 'open_writers' violation is not detected in the following case: policy: measure func=FILE_MMAP mask=MAY_EXEC steps: 1) open a shared library for writing 2) execute a binary that links that shared library 3) during the binary execution, modify the shared library and save the change result: the 'open_writers' violation measurement is not present in the IMA list. Only binaries executed are protected from writes. For libraries mapped in memory there is the flag MAP_DENYWRITE for this purpose, but according to the output of 'man mmap', the mmap flag is ignored. Since ima_rdwr_violation_check() is now called by process_measurement() the information about if the inode must be measured is already provided by ima_get_action(). Thus the unnecessary function ima_must_measure() has been removed. Changes in v3 (Dmitry Kasatkin): - Violation for MMAP_CHECK function are verified since this patch - Changed patch description a bit Signed-off-by: Roberto Sassu Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar

ima: remove usage of filename parameter

2014-09-09T14:28:52+00:00

In all cases except ima_bprm_check() the filename was not defined and ima_d_path() was used to find the full path. Unfortunately, the bprm filename is a relative pathname (eg. .//filename). ima_bprm_check() selects between bprm->interp and bprm->filename. The following dump demonstrates the differences between using filename and interp. bprm->filename filename: ./foo.sh, pathname: /root/bin/foo.sh filename: ./foo.sh, pathname: /bin/dash bprm->interp filename: ./foo.sh, pathname: /root/bin/foo.sh filename: /bin/sh, pathname: /bin/dash In both cases the pathnames are currently the same. This patch removes usage of filename and interp in favor of d_absolute_path. Changes v3: - 11 extra bytes for "deleted" not needed (Mimi) - purpose "replace relative bprm filename with full pathname" (Mimi) Changes v2: - use d_absolute_path() instead of d_path to work in chroot environments. Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar

ima: audit log files opened with O_DIRECT flag

2014-06-03T19:21:50+00:00

Files are measured or appraised based on the IMA policy. When a file, in policy, is opened with the O_DIRECT flag, a deadlock occurs. The first attempt at resolving this lockdep temporarily removed the O_DIRECT flag and restored it, after calculating the hash. The second attempt introduced the O_DIRECT_HAVELOCK flag. Based on this flag, do_blockdev_direct_IO() would skip taking the i_mutex a second time. The third attempt, by Dmitry Kasatkin, resolves the i_mutex locking issue, by re-introducing the IMA mutex, but uncovered another problem. Reading a file with O_DIRECT flag set, writes directly to userspace pages. A second patch allocates a user-space like memory. This works for all IMA hooks, except ima_file_free(), which is called on __fput() to recalculate the file hash. Until this last issue is addressed, do not 'collect' the measurement for measuring, appraising, or auditing files opened with the O_DIRECT flag set. Based on policy, permit or deny file access. This patch defines a new IMA policy rule option named 'permit_directio'. Policy rules could be defined, based on LSM or other criteria, to permit specific applications to open files with the O_DIRECT flag set. Changelog v1: - permit or deny file access based IMA policy rules Signed-off-by: Mimi Zohar Acked-by: Dmitry Kasatkin Cc:

ima: return d_name.name if d_path fails

2014-03-07T17:15:46+00:00

This is a small refactoring so ima_d_path() returns dentry name if path reconstruction fails. It simplifies callers actions and removes code duplication. Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar

integrity: fix checkpatch errors

2014-03-07T17:15:45+00:00

Between checkpatch changes (eg. sizeof) and inconsistencies between Lindent and checkpatch, unfixed checkpatch errors make it difficult to see new errors. This patch fixes them. Some lines with over 80 chars remained unchanged to improve code readability. The "extern" keyword is removed from internal evm.h to make it consistent with internal ima.h. Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar

ima: use static const char array definitions

2014-03-07T16:30:36+00:00

A const char pointer allocates memory for a pointer as well as for a string, This patch replaces a number of the const char pointers throughout IMA, with a static const char array. Suggested-by: David Howells Signed-off-by: Mimi Zohar Acked-by: David Howells

ima: new helper: file_inode(file)

2014-03-04T21:53:03+00:00

Replace "file->f_dentry->d_inode" with the new file_inode() helper function. Signed-off-by: Libo Chen Signed-off-by: Mimi Zohar

ima: properly free ima_template_entry structures

2013-12-03T01:46:56+00:00

The new templates management mechanism records information associated to an event into an array of 'ima_field_data' structures and makes it available through the 'template_data' field of the 'ima_template_entry' structure (the element of the measurements list created by IMA). Since 'ima_field_data' contains dynamically allocated data (which length varies depending on the data associated to a selected template field), it is not enough to just free the memory reserved for a 'ima_template_entry' structure if something goes wrong. This patch creates the new function ima_free_template_entry() which walks the array of 'ima_field_data' structures, frees the memory referenced by the 'data' pointer and finally the space reserved for the 'ima_template_entry' structure. Further, it replaces existing kfree() that have a pointer to an 'ima_template_entry' structure as argument with calls to the new function. Fixes: a71dc65: ima: switch to new template management mechanism Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar

ima: do not include field length in template digest calc for ima template

2013-11-25T12:26:28+00:00

To maintain compatibility with userspace tools, the field length must not be included in the template digest calculation for the 'ima' template. Fixes commit: a71dc65 ima: switch to new template management mechanism Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar

ima: extend the measurement list to include the file signature

2013-11-01T00:19:35+00:00

This patch defines a new template called 'ima-sig', which includes the file signature in the template data, in addition to the file's digest and pathname. A template is composed of a set of fields. Associated with each field is an initialization and display function. This patch defines a new template field called 'sig', the initialization function ima_eventsig_init(), and the display function ima_show_template_sig(). This patch modifies the .field_init() function definition to include the 'security.ima' extended attribute and length. Changelog: - remove unused code (Dmitry Kasatkin) - avoid calling ima_write_template_field_data() unnecesarily (Roberto Sassu) - rename DATA_FMT_SIG to DATA_FMT_HEX - cleanup ima_eventsig_init() based on Roberto's comments Signed-off-by: Mimi Zohar Signed-off-by: Dmitry Kasatkin Signed-off-by: Roberto Sassu