linux-stable.git/security/integrity/evm, branch linux-6.8.y

evm: add support to disable EVM on unsupported filesystems

2023-12-20T12:40:07+00:00

Identify EVM unsupported filesystems by defining a new flag
SB_I_EVM_UNSUPPORTED.

Don't verify, write, remove or update 'security.evm' on unsupported
filesystems.

Acked-by: Amir Goldstein 
Reviewed-by: Christian Brauner 
Signed-off-by: Mimi Zohar

evm: don't copy up 'security.evm' xattr

2023-12-20T12:39:52+00:00

The security.evm HMAC and the original file signatures contain
filesystem specific data.  As a result, the HMAC and signature
are not the same on the stacked and backing filesystems.

Don't copy up 'security.evm'.

Reviewed-by: Amir Goldstein 
Reviewed-by: Christian Brauner 
Signed-off-by: Mimi Zohar

evm: Do not include crypto/algapi.h

2023-09-15T10:30:43+00:00

The header file crypto/algapi.h is for internal use only.  Use the
header file crypto/utils.h instead.

Acked-by: Mimi Zohar 
Signed-off-by: Herbert Xu

Merge tag 'lsm-pr-20230829' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm

2023-08-30T16:07:09+00:00

Pull LSM updates from Paul Moore:

 - Add proper multi-LSM support for xattrs in the
   security_inode_init_security() hook

   Historically the LSM layer has only allowed a single LSM to add an
   xattr to an inode, with IMA/EVM measuring that and adding its own as
   well. As we work towards promoting IMA/EVM to a "proper LSM" instead
   of the special case that it is now, we need to better support the
   case of multiple LSMs each adding xattrs to an inode and after
   several attempts we now appear to have something that is working
   well. It is worth noting that in the process of making this change we
   uncovered a problem with Smack's SMACK64TRANSMUTE xattr which is also
   fixed in this pull request.

 - Additional LSM hook constification

   Two patches to constify parameters to security_capget() and
   security_binder_transfer_file(). While I generally don't make a
   special note of who submitted these patches, these were the work of
   an Outreachy intern, Khadija Kamran, and that makes me happy;
   hopefully it does the same for all of you reading this.

 - LSM hook comment header fixes

   One patch to add a missing hook comment header, one to fix a minor
   typo.

 - Remove an old, unused credential function declaration

   It wasn't clear to me who should pick this up, but it was trivial,
   obviously correct, and arguably the LSM layer has a vested interest
   in credentials so I merged it. Sadly I'm now noticing that despite my
   subject line cleanup I didn't cleanup the "unsued" misspelling, sigh

* tag 'lsm-pr-20230829' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
  lsm: constify the 'file' parameter in security_binder_transfer_file()
  lsm: constify the 'target' parameter in security_capget()
  lsm: add comment block for security_sk_classify_flow LSM hook
  security: Fix ret values doc for security_inode_init_security()
  cred: remove unsued extern declaration change_create_files_as()
  evm: Support multiple LSMs providing an xattr
  evm: Align evm_inode_init_security() definition with LSM infrastructure
  smack: Set the SMACK64TRANSMUTE xattr in smack_inode_init_security()
  security: Allow all LSMs to provide xattrs for inode_init_security hook
  lsm: fix typo in security_file_lock() comment header

integrity: Enforce digitalSignature usage in the ima and evm keyrings

2023-08-17T20:12:35+00:00

After being vouched for by a system keyring, only allow keys into the .ima
and .evm keyrings that have the digitalSignature usage field set.

Link: https://lore.kernel.org/all/41dffdaeb7eb7840f7e38bc691fbda836635c9f9.camel@linux.ibm.com
Suggested-by: Mimi Zohar 
Signed-off-by: Eric Snowberg 
Acked-and-tested-by: Mimi Zohar 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen

evm: Support multiple LSMs providing an xattr

2023-07-10T17:59:39+00:00

Currently, evm_inode_init_security() processes a single LSM xattr from the
array passed by security_inode_init_security(), and calculates the HMAC on
it and other inode metadata.

As the LSM infrastructure now can pass to EVM an array with multiple
xattrs, scan them until the terminator (xattr name NULL), and calculate the
HMAC on all of them.

Also, double check that the xattrs array terminator is the first non-filled
slot (obtained with lsm_get_xattr_slot()). Consumers of the xattrs array,
such as the initxattrs() callbacks, rely on the terminator.

Finally, change the name of the lsm_xattr parameter of evm_init_hmac() to
xattrs, to reflect the new type of information passed.

Signed-off-by: Roberto Sassu 
Reviewed-by: Mimi Zohar 
Acked-by: Mimi Zohar 
Signed-off-by: Paul Moore

evm: Align evm_inode_init_security() definition with LSM infrastructure

2023-07-10T17:59:38+00:00

Change the evm_inode_init_security() definition to align with the LSM
infrastructure. Keep the existing behavior of including in the HMAC
calculation only the first xattr provided by LSMs.

Changing the evm_inode_init_security() definition requires passing the
xattr array allocated by security_inode_init_security(), and the number of
xattrs filled by previously invoked LSMs.

Use the newly introduced lsm_get_xattr_slot() to position EVM correctly in
the xattrs array, like a regular LSM, and to increment the number of filled
slots. For now, the LSM infrastructure allocates enough xattrs slots to
store the EVM xattr, without using the reservation mechanism.

Signed-off-by: Roberto Sassu 
Reviewed-by: Mimi Zohar 
Acked-by: Mimi Zohar 
Signed-off-by: Paul Moore

evm: Fix build warnings

2023-06-06T12:51:11+00:00

Fix build warnings (function parameters description) for
evm_read_protected_xattrs(), evm_set_key() and evm_verifyxattr().

Fixes: 7626676320f3 ("evm: provide a function to set the EVM key from the kernel") # v4.5+
Fixes: 8314b6732ae4 ("ima: Define new template fields xattrnames, xattrlengths and xattrvalues") # v5.14+
Fixes: 2960e6cb5f7c ("evm: additional parameter to pass integrity cache entry 'iint'") # v3.2+
Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar

evm: Complete description of evm_inode_setattr()

2023-06-05T13:04:41+00:00

Add the description for missing parameters of evm_inode_setattr() to
avoid the warning arising with W=n compile option.

Fixes: 817b54aa45db ("evm: add evm_inode_setattr to prevent updating an invalid security.evm") # v3.2+
Fixes: c1632a0f1120 ("fs: port ->setattr() to pass mnt_idmap") # v6.3+
Signed-off-by: Roberto Sassu 
Reviewed-by: Stefan Berger 
Signed-off-by: Mimi Zohar

Merge tag 'integrity-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2023-02-22T20:36:25+00:00

Pull integrity update from Mimi Zohar:
 "One doc and one code cleanup, and two bug fixes"

* tag 'integrity-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  ima: Introduce MMAP_CHECK_REQPROT hook
  ima: Align ima_file_mmap() parameters with mmap_file LSM hook
  evm: call dump_security_xattr() in all cases to remove code duplication
  ima: fix ima_delete_rules() kernel-doc warning
  ima: return IMA digest value only when IMA_COLLECTED flag is set
  ima: fix error handling logic when file measurement failed