Commit Graph

6 Commits

Author SHA1 Message Date
Madhuparna Bhowmik 80dd1bfaba evm: Fix RCU list related warnings
[ 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 <lkp@intel.com>
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org> (RCU viewpoint)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-16 16:28:47 +08:00
Dan Carpenter acb30a14d4 evm: Fix a small race in init_desc()
[ Upstream commit 8433856947217ebb5697a8ff9c4c9cad4639a2cf ]

The IS_ERR_OR_NULL() function has two conditions and if we got really
unlucky we could hit a race where "ptr" started as an error pointer and
then was set to NULL.  Both conditions would be false even though the
pointer at the end was NULL.

This patch fixes the problem by ensuring that "*tfm" can only be NULL
or valid.  I have introduced a "tmp_tfm" variable to make that work.  I
also reversed a condition and pulled the code in one tab.

Reported-by: Roberto Sassu <roberto.sassu@huawei.com>
Fixes: 53de3b080d5e ("evm: Check also if *tfm is an error pointer in init_desc()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-16 16:28:07 +08:00
Roberto Sassu c382d9fa06 ima: Fix return value of ima_write_policy()
[ Upstream commit 2e3a34e9f409ebe83d1af7cd2f49fca7af97dfac ]

This patch fixes the return value of ima_write_policy() when a new policy
is directly passed to IMA and the current policy requires appraisal of the
file containing the policy. Currently, if appraisal is not in ENFORCE mode,
ima_write_policy() returns 0 and leads user space applications to an
endless loop. Fix this issue by denying the operation regardless of the
appraisal mode.

Cc: stable@vger.kernel.org # 4.10.x
Fixes: 19f8a84713edc ("ima: measure and appraise the IMA policy itself")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-16 16:28:06 +08:00
Roberto Sassu 90e944aa9a evm: Check also if *tfm is an error pointer in init_desc()
[ 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 <krzysztof.struczynski@huawei.com>
Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-16 16:28:06 +08:00
Roberto Sassu c73215b82c ima: Set file->f_mode instead of file->f_flags in ima_calc_file_hash()
[ Upstream commit 0014cc04e8ec077dc482f00c87dfd949cfe2b98f ]

Commit a408e4a86b36 ("ima: open a new file instance if no read
permissions") tries to create a new file descriptor to calculate a file
digest if the file has not been opened with O_RDONLY flag. However, if a
new file descriptor cannot be obtained, it sets the FMODE_READ flag to
file->f_flags instead of file->f_mode.

This patch fixes this issue by replacing f_flags with f_mode as it was
before that commit.

Cc: stable@vger.kernel.org # 4.20.x
Fixes: a408e4a86b36 ("ima: open a new file instance if no read permissions")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-16 16:28:06 +08:00
Kaixu Xia 590eaf1fec Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
2021-03-16 11:01:34 +08:00