linux.git/security/integrity/ima/ima_main.c, branch v4.10.4

ima: fix ima_d_path() possible race with rename

2017-03-12T05:44:10+00:00

commit bc15ed663e7e53ee4dc3e60f8d09c93a0528c694 upstream.

On failure to return a pathname from ima_d_path(), a pointer to
dname is returned, which is subsequently used in the IMA measurement
list, the IMA audit records, and other audit logging.  Saving the
pointer to dname for later use has the potential to race with rename.

Intead of returning a pointer to dname on failure, this patch returns
a pointer to a copy of the filename.

Reported-by: Al Viro 
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

ima: store the builtin/custom template definitions in a list

2016-12-20T17:48:45+00:00

The builtin and single custom templates are currently stored in an
array.  In preparation for being able to restore a measurement list
containing multiple builtin/custom templates, this patch stores the
builtin and custom templates as a linked list.  This will permit
defining more than one custom template per boot.

Link: http://lkml.kernel.org/r/1480554346-29071-8-git-send-email-zohar@linux.vnet.ibm.com
Signed-off-by: Mimi Zohar 
Acked-by: Dmitry Kasatkin 
Cc: Thiago Jung Bauermann 
Cc: "Eric W. Biederman" 
Cc: Andreas Steffen 
Cc: Josh Sklar 
Cc: Dave Young 
Cc: Vivek Goyal 
Cc: Baoquan He 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Stewart Smith 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ima: use file_dentry()

2016-09-16T10:44:20+00:00

Ima tries to call ->setxattr() on overlayfs dentry after having locked
underlying inode, which results in a deadlock.

Reported-by: Krisztian Litkey 
Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Signed-off-by: Miklos Szeredi 
Cc:  # v4.2
Cc: Mimi Zohar

ima: change integrity cache to store measured pcr

2016-06-30T05:14:22+00:00

IMA avoids re-measuring files by storing the current state as a flag in
the integrity cache. It will then skip adding a new measurement log entry
if the cache reports the file as already measured.

If a policy measures an already measured file to a new PCR, the measurement
will not be added to the list. This patch implements a new bitfield for
specifying which PCR the file was measured into, rather than if it was
measured.

Signed-off-by: Eric Richter 
Signed-off-by: Mimi Zohar

ima: include pcr for each measurement log entry

2016-06-30T05:14:21+00:00

The IMA measurement list entries include the Kconfig defined PCR value.
This patch defines a new ima_template_entry field for including the PCR
as specified in the policy rule.

Signed-off-by: Eric Richter 
Signed-off-by: Mimi Zohar

ima: extend ima_get_action() to return the policy pcr

2016-06-30T05:14:20+00:00

Different policy rules may extend different PCRs. This patch retrieves
the specific PCR for the matched rule.  Subsequent patches will include
the rule specific PCR in the measurement list and extend the appropriate
PCR.

Signed-off-by: Eric Richter 
Signed-off-by: Mimi Zohar

ima: add support for creating files using the mknodat syscall

2016-05-01T13:23:52+00:00

Commit 3034a14 "ima: pass 'opened' flag to identify newly created files"
stopped identifying empty files as new files.  However new empty files
can be created using the mknodat syscall.  On systems with IMA-appraisal
enabled, these empty files are not labeled with security.ima extended
attributes properly, preventing them from subsequently being opened in
order to write the file data contents.  This patch defines a new hook
named ima_post_path_mknod() to mark these empty files, created using
mknodat, as new in order to allow the file data contents to be written.

In addition, files with security.ima xattrs containing a file signature
are considered "immutable" and can not be modified.  The file contents
need to be written, before signing the file.  This patch relaxes this
requirement for new files, allowing the file signature to be written
before the file contents.

Changelog:
- defer identifying files with signatures stored as security.ima
  (based on Dmitry Rozhkov's comments)
- removing tests (eg. dentry, dentry->d_inode, inode->i_size == 0)
  (based on Al's review)

Signed-off-by: Mimi Zohar 
Cc: Al Viro <
Tested-by: Dmitry Rozhkov

ima: measure and appraise the IMA policy itself

2016-02-21T14:34:22+00:00

Add support for measuring and appraising the IMA policy itself.

Changelog v4:
- use braces on both if/else branches, even if single line on one of the
branches - Dmitry
- Use the id mapping - Dmitry

Signed-off-by: Mimi Zohar 
Acked-by: Petko Manolov 
Acked-by: Dmitry Kasatkin

ima: support for kexec image and initramfs

2016-02-21T14:06:16+00:00

Add IMA policy support for measuring/appraising the kexec image and
initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and
KEXEC_INITRAMFS_CHECK are defined.

Example policy rules:
measure func=KEXEC_KERNEL_CHECK
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig
measure func=KEXEC_INITRAMFS_CHECK
appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig

Moving the enumeration to the vfs layer simplified the patches, allowing
the IMA changes, for the most part, to be separated from the other
changes.  Unfortunately, passing either a kernel_read_file_id or a
ima_hooks enumeration within IMA is messy.

Option 1: duplicate kernel_read_file enumeration in ima_hooks

enum kernel_read_file_id {
	...
        READING_KEXEC_IMAGE,
        READING_KEXEC_INITRAMFS,
        READING_MAX_ID

enum ima_hooks {
	...
	KEXEC_KERNEL_CHECK
	KEXEC_INITRAMFS_CHECK

Option 2: define ima_hooks as extension of kernel_read_file
eg: enum ima_hooks {
        FILE_CHECK = READING_MAX_ID,
        MMAP_CHECK,

In order to pass both kernel_read_file_id and ima_hooks values, we
would need to specify a struct containing a union.

struct caller_id {
        union {
                enum ima_hooks func_id;
                enum kernel_read_file_id read_id;
        };
};

Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id,
perhaps changing the enumeration name.

For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks.

Changelog v4:
- replaced switch statement with a kernel_read_file_id to an ima_hooks
id mapping array - Dmitry
- renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to
KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young

Signed-off-by: Mimi Zohar 
Acked-by: Petko Manolov 
Acked-by: Dmitry Kasatkin 
Cc: Dave Young

module: replace copy_module_from_fd with kernel version

2016-02-21T14:06:12+00:00

Replace copy_module_from_fd() with kernel_read_file_from_fd().

Although none of the upstreamed LSMs define a kernel_module_from_file
hook, IMA is called, based on policy, to prevent unsigned kernel modules
from being loaded by the original kernel module syscall and to
measure/appraise signed kernel modules.

The security function security_kernel_module_from_file() was called prior
to reading a kernel module.  Preventing unsigned kernel modules from being
loaded by the original kernel module syscall remains on the pre-read
kernel_read_file() security hook.  Instead of reading the kernel module
twice, once for measuring/appraising and again for loading the kernel
module, the signature validation is moved to the kernel_post_read_file()
security hook.

This patch removes the security_kernel_module_from_file() hook and security
call.

Signed-off-by: Mimi Zohar 
Acked-by: Kees Cook 
Acked-by: Luis R. Rodriguez 
Cc: Rusty Russell