linux-stable.git/security/integrity/evm, branch v4.19.166

evm: Check size of security.evm before using it

2020-11-05T10:08:34+00:00

commit 455b6c9112eff8d249e32ba165742085678a80a4 upstream.

This patch checks the size for the EVM_IMA_XATTR_DIGSIG and
EVM_XATTR_PORTABLE_DIGSIG types to ensure that the algorithm is read from
the buffer returned by vfs_getxattr_alloc().

Cc: stable@vger.kernel.org # 4.19.x
Fixes: 5feeb61183dde ("evm: Allow non-SHA1 digital signatures")
Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

evm: Fix possible memory leak in evm_calc_hmac_or_hash()

2020-06-22T07:05:21+00:00

commit 0c4395fb2aa77341269ea619c5419ea48171883f upstream.

Don't immediately return if the signature is portable and security.ima is
not present. Just set error so that memory allocated is freed before
returning from evm_calc_hmac_or_hash().

Fixes: 50b977481fce9 ("EVM: Add support for portable signature format")
Signed-off-by: Roberto Sassu 
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

evm: Fix RCU list related warnings

2020-06-07T11:17:56+00:00

[ Upstream commit 770f60586d2af0590be263f55fd079226313922c ]

This patch fixes the following warning and few other instances of
traversal of evm_config_xattrnames list:

[   32.848432] =============================
[   32.848707] WARNING: suspicious RCU usage
[   32.848966] 5.7.0-rc1-00006-ga8d5875ce5f0b #1 Not tainted
[   32.849308] -----------------------------
[   32.849567] security/integrity/evm/evm_main.c:231 RCU-list traversed in non-reader section!!

Since entries are only added to the list and never deleted, use
list_for_each_entry_lockless() instead of list_for_each_entry_rcu for
traversing the list.  Also, add a relevant comment in evm_secfs.c to
indicate this fact.

Reported-by: kernel test robot 
Suggested-by: Paul E. McKenney 
Signed-off-by: Madhuparna Bhowmik 
Acked-by: Paul E. McKenney  (RCU viewpoint)
Signed-off-by: Mimi Zohar 
Signed-off-by: Sasha Levin

evm: Check also if *tfm is an error pointer in init_desc()

2020-05-27T15:37:28+00:00

[ Upstream commit 53de3b080d5eae31d0de219617155dcc34e7d698 ]

This patch avoids a kernel panic due to accessing an error pointer set by
crypto_alloc_shash(). It occurs especially when there are many files that
require an unsupported algorithm, as it would increase the likelihood of
the following race condition:

Task A: *tfm = crypto_alloc_shash() <= error pointer
Task B: if (*tfm == NULL) <= *tfm is not NULL, use it
Task B: rc = crypto_shash_init(desc) <= panic
Task A: *tfm = NULL

This patch uses the IS_ERR_OR_NULL macro to determine whether or not a new
crypto context must be created.

Cc: stable@vger.kernel.org
Fixes: d46eb3699502b ("evm: crypto hash replaced by shash")
Co-developed-by: Krzysztof Struczynski 
Signed-off-by: Krzysztof Struczynski 
Signed-off-by: Roberto Sassu 
Signed-off-by: Mimi Zohar 
Signed-off-by: Sasha Levin

evm: check hash algorithm passed to init_desc()

2019-06-09T07:17:21+00:00

commit 221be106d75c1b511973301542f47d6000d0b63e upstream.

This patch prevents memory access beyond the evm_tfm array by checking the
validity of the index (hash algorithm) passed to init_desc(). The hash
algorithm can be arbitrarily set if the security.ima xattr type is not
EVM_XATTR_HMAC.

Fixes: 5feeb61183dde ("evm: Allow non-SHA1 digital signatures")
Signed-off-by: Roberto Sassu 
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

EVM: fix return value check in evm_write_xattrs()

2018-07-22T18:49:11+00:00

In case of error, the function audit_log_start() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should be
replaced with NULL test.

Fixes: fa516b66a1bf ("EVM: Allow runtime modification of the set of verified xattrs")
Signed-off-by: Wei Yongjun 
Acked-by: Serge Hallyn 
Signed-off-by: Mimi Zohar

evm: Allow non-SHA1 digital signatures

2018-07-18T11:27:22+00:00

SHA1 is reasonable in HMAC constructs, but it's desirable to be able to
use stronger hashes in digital signatures. Modify the EVM crypto code so
the hash type is imported from the digital signature and passed down to
the hash calculation code, and return the digest size to higher layers
for validation.

Signed-off-by: Matthew Garrett 
Signed-off-by: Mimi Zohar

evm: Don't deadlock if a crypto algorithm is unavailable

2018-07-18T11:27:22+00:00

When EVM attempts to appraise a file signed with a crypto algorithm the
kernel doesn't have support for, it will cause the kernel to trigger a
module load. If the EVM policy includes appraisal of kernel modules this
will in turn call back into EVM - since EVM is holding a lock until the
crypto initialisation is complete, this triggers a deadlock. Add a
CRYPTO_NOLOAD flag and skip module loading if it's set, and add that flag
in the EVM case in order to fail gracefully with an error message
instead of deadlocking.

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

Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2018-06-07T22:40:37+00:00

Pull integrity updates from James Morris:
 "From Mimi:

   - add run time support for specifying additional security xattrs
     included in the security.evm HMAC/signature

   - some code clean up and bug fixes"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  EVM: unlock on error path in evm_read_xattrs()
  EVM: prevent array underflow in evm_write_xattrs()
  EVM: Fix null dereference on xattr when xattr fails to allocate
  EVM: fix memory leak of temporary buffer 'temp'
  IMA: use list_splice_tail_init_rcu() instead of its open coded variant
  ima: use match_string() helper
  ima: fix updating the ima_appraise flag
  ima: based on policy verify firmware signatures (pre-allocated buffer)
  ima: define a new policy condition based on the filesystem name
  EVM: Allow runtime modification of the set of verified xattrs
  EVM: turn evm_config_xattrnames into a list
  integrity: Add an integrity directory in securityfs
  ima: Remove unused variable ima_initialized
  ima: Unify logging
  ima: Reflect correct permissions for policy

EVM: unlock on error path in evm_read_xattrs()

2018-06-01T10:03:08+00:00

We need to unlock before returning on this error path.

Fixes: fa516b66a1bf ("EVM: Allow runtime modification of the set of verified xattrs")
Signed-off-by: Dan Carpenter 
Signed-off-by: Mimi Zohar