[ Upstream commit 91e326563e ]
Changing the direct dependencies of IMA_BLACKLIST_KEYRING and
IMA_LOAD_X509 caused them to no longer depend on IMA, but a
a configuration without IMA results in link failures:
arm-linux-gnueabi-ld: security/integrity/iint.o: in function `integrity_load_keys':
iint.c:(.init.text+0xd8): undefined reference to `ima_load_x509'
aarch64-linux-ld: security/integrity/digsig_asymmetric.o: in function `asymmetric_verify':
digsig_asymmetric.c:(.text+0x104): undefined reference to `ima_blacklist_keyring'
Adding explicit dependencies on IMA would fix this, but a more reliable
way to do this is to enclose the entire Kconfig file in an 'if IMA' block.
This also allows removing the existing direct dependencies.
Fixes: be210c6d35 ("ima: Finish deprecation of IMA_TRUSTED_KEYRING Kconfig")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit be210c6d35 ]
The removal of IMA_TRUSTED_KEYRING made IMA_LOAD_X509
and IMA_BLACKLIST_KEYRING unavailable because the latter
two depend on the former. Since IMA_TRUSTED_KEYRING was
deprecated in favor of INTEGRITY_TRUSTED_KEYRING use it
as a dependency for the two Kconfigs affected by the
deprecation.
Fixes: 5087fd9e80 ("ima: Remove deprecated IMA_TRUSTED_KEYRING Kconfig")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 644f17412f ]
UML supports HAS_IOMEM since 0bbadafdc4 (um: allow disabling
NO_IOMEM).
Current IMA build on UML fails on allmodconfig (with TCG_TPM=m):
ld: security/integrity/ima/ima_queue.o: in function `ima_add_template_entry':
ima_queue.c:(.text+0x2d9): undefined reference to `tpm_pcr_extend'
ld: security/integrity/ima/ima_init.o: in function `ima_init':
ima_init.c:(.init.text+0x43f): undefined reference to `tpm_default_chip'
ld: security/integrity/ima/ima_crypto.o: in function `ima_calc_boot_aggregate_tfm':
ima_crypto.c:(.text+0x1044): undefined reference to `tpm_pcr_read'
ld: ima_crypto.c:(.text+0x10d8): undefined reference to `tpm_pcr_read'
Modify the IMA Kconfig entry so that it selects TCG_TPM if HAS_IOMEM
is set, regardless of the UML Kconfig setting.
This updates TCG_TPM from =m to =y and fixes the linker errors.
Fixes: f4a0391dfa ("ima: fix Kconfig dependencies")
Cc: Stable <stable@vger.kernel.org> # v5.14+
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-um@lists.infradead.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4971c268b8 upstream.
Commit 98de59bfe4 ("take calculation of final prot in
security_mmap_file() into a helper") moved the code to update prot, to be
the actual protections applied to the kernel, to a new helper called
mmap_prot().
However, while without the helper ima_file_mmap() was getting the updated
prot, with the helper ima_file_mmap() gets the original prot, which
contains the protections requested by the application.
A possible consequence of this change is that, if an application calls
mmap() with only PROT_READ, and the kernel applies PROT_EXEC in addition,
that application would have access to executable memory without having this
event recorded in the IMA measurement list. This situation would occur for
example if the application, before mmap(), calls the personality() system
call with READ_IMPLIES_EXEC as the first argument.
Align ima_file_mmap() parameters with those of the mmap_file LSM hook, so
that IMA can receive both the requested prot and the final prot. Since the
requested protections are stored in a new variable, and the final
protections are stored in the existing variable, this effectively restores
the original behavior of the MMAP_CHECK hook.
Cc: stable@vger.kernel.org
Fixes: 98de59bfe4 ("take calculation of final prot in security_mmap_file() into a helper")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d57378d3aa ]
Currently ima_lsm_copy_rule() set the arg_p field of the source rule to
NULL, so that the source rule could be freed afterward. It does not make
sense for this behavior to be inside a "copy" function. So move it
outside and let the caller handle this field.
ima_lsm_copy_rule() now produce a shallow copy of the original entry
including args_p field. Meaning only the lsm.rule and the rule itself
should be freed for the original rule. Thus, instead of calling
ima_lsm_free_rule() which frees lsm.rule as well as args_p field, free
the lsm.rule directly.
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 25369175ce ]
The input parameter @fields is type of struct ima_template_field ***, so
when allocates array memory for @fields, the size of element should be
sizeof(**field) instead of sizeof(*field).
Actually the original code would not cause any runtime error, but it's
better to make it logically right.
Fixes: adf53a778a ("ima: new templates management mechanism")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c7423dbdbc ]
IMA relies on the blocking LSM policy notifier callback to update the
LSM based IMA policy rules.
When SELinux update its policies, IMA would be notified and starts
updating all its lsm rules one-by-one. During this time, -ESTALE would
be returned by ima_filter_rule_match() if it is called with a LSM rule
that has not yet been updated. In ima_match_rules(), -ESTALE is not
handled, and the LSM rule is considered a match, causing extra files
to be measured by IMA.
Fix it by re-initializing a temporary rule if -ESTALE is returned by
ima_filter_rule_match(). The origin rule in the rule list would be
updated by the LSM policy notifier callback.
Fixes: b169424551 ("ima: use the lsm policy update notifier")
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 28073eb09c ]
In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly adding multiple break statements instead of just
letting the code fall through to the next case.
Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Stable-dep-of: c7423dbdbc ("ima: Handle -ESTALE returned by ima_filter_rule_match()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 543ce63b66 upstream.
The lockdown LSM is primarily used in conjunction with UEFI Secure Boot.
This LSM may also be used on machines without UEFI. It can also be
enabled when UEFI Secure Boot is disabled. One of lockdown's features
is to prevent kexec from loading untrusted kernels. Lockdown can be
enabled through a bootparam or after the kernel has booted through
securityfs.
If IMA appraisal is used with the "ima_appraise=log" boot param,
lockdown can be defeated with kexec on any machine when Secure Boot is
disabled or unavailable. IMA prevents setting "ima_appraise=log" from
the boot param when Secure Boot is enabled, but this does not cover
cases where lockdown is used without Secure Boot.
To defeat lockdown, boot without Secure Boot and add ima_appraise=log to
the kernel command line; then:
$ echo "integrity" > /sys/kernel/security/lockdown
$ echo "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig" > \
/sys/kernel/security/ima/policy
$ kexec -ls unsigned-kernel
Add a call to verify ima appraisal is set to "enforce" whenever lockdown
is enabled. This fixes CVE-2022-21505.
Cc: stable@vger.kernel.org
Fixes: 29d3c1c8df ("kexec: Allow kexec_file() with appropriate IMA policy when locked down")
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: John Haxby <john.haxby@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 067d252187 ]
On failure to allocate the SHA1 tfm, IMA fails to initialize and exits
without freeing the ima_algo_array. Add the missing kfree() for
ima_algo_array to avoid the potential memory leak.
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Fixes: 6d94809af6 ("ima: Allocate and initialize tfm for each PCR bank")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d2ee2cfc4a ]
When the ima-modsig is enabled, the rc passed to evm_verifyxattr() may be
negative, which may cause the integer overflow problem.
Fixes: 39b0709636 ("ima: Implement support for module-style appended signatures")
Signed-off-by: Huaxin Lu <luhuaxin1@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 891163adf1 upstream.
The original 'ima' measurement list template contains a hash, defined
as 20 bytes, and a null terminated pathname, limited to 255
characters. Other measurement list templates permit both larger hashes
and longer pathnames. When the "ima" template is configured as the
default, a new measurement list template (ima_template=) must be
specified before specifying a larger hash algorithm (ima_hash=) on the
boot command line.
To avoid this boot command line ordering issue, remove the legacy "ima"
template configuration option, allowing it to still be specified on the
boot command line.
The root cause of this issue is that during the processing of ima_hash,
we would try to check whether the hash algorithm is compatible with the
template. If the template is not set at the moment we do the check, we
check the algorithm against the configured default template. If the
default template is "ima", then we reject any hash algorithm other than
sha1 and md5.
For example, if the compiled default template is "ima", and the default
algorithm is sha1 (which is the current default). In the cmdline, we put
in "ima_hash=sha256 ima_template=ima-ng". The expected behavior would be
that ima starts with ima-ng as the template and sha256 as the hash
algorithm. However, during the processing of "ima_hash=",
"ima_template=" has not been processed yet, and hash_setup would check
the configured hash algorithm against the compiled default: ima, and
reject sha256. So at the end, the hash algorithm that is actually used
will be sha1.
With template "ima" removed from the configured default, we ensure that
the default tempalte would at least be "ima-ng" which allows for
basically any hash algorithm.
This change would not break the algorithm compatibility checks for IMA.
Fixes: 4286587dcc ("ima: add Kconfig default measurement list template")
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bb8e52e490 upstream.
Commit c2426d2ad5 ("ima: added support for new kernel cmdline parameter
ima_template_fmt") introduced an additional check on the ima_template
variable to avoid multiple template selection.
Unfortunately, ima_template could be also set by the setup function of the
ima_hash= parameter, when it calls ima_template_desc_current(). This causes
attempts to choose a new template with ima_template= or with
ima_template_fmt=, after ima_hash=, to be ignored.
Achieve the goal of the commit mentioned with the new static variable
template_setup_done, so that template selection requests after ima_hash=
are not ignored.
Finally, call ima_init_template_list(), if not already done, to initialize
the list of templates before lookup_template_desc() is called.
Reported-by: Guo Zihua <guozihua@huawei.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: stable@vger.kernel.org
Fixes: c2426d2ad5 ("ima: added support for new kernel cmdline parameter ima_template_fmt")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8510505d55 upstream.
MD5 is a weak digest algorithm that shouldn't be used for cryptographic
operation. It hinders the efficiency of a patch set that aims to limit
the digests allowed for the extended file attribute namely security.ima.
MD5 is no longer a requirement for IMA, nor should it be used there.
The sole place where we still use the MD5 algorithm inside IMA is setting
the ima_hash algorithm to MD5, if the user supplies 'ima_hash=md5'
parameter on the command line. With commit ab60368ab6 ("ima: Fallback
to the builtin hash algorithm"), setting "ima_hash=md5" fails gracefully
when CRYPTO_MD5 is not set:
ima: Can not allocate md5 (reason: -2)
ima: Allocating md5 failed, going to use default hash algorithm sha256
Remove the CRYPTO_MD5 dependency for IMA.
Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
[zohar@linux.ibm.com: include commit number in patch description for
stable.]
Cc: stable@vger.kernel.org # 4.17
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7990ccafaa ]
In ima_restore_measurement_list(), hdr[HDR_PCR].data is pointing to a
buffer of type u8, which contains the dumped 32-bit pcr value.
Currently, only the least significant byte is used to restore the pcr
value. We should convert hdr[HDR_PCR].data to a pointer of type u32
before fetching the value to restore the correct pcr value.
Fixes: 47fdee60b4 ("ima: use ima_parse_buf() to parse measurements headers")
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4993e1f947 ]
KEY_FLAG_KEEP is not meant to be passed to keyring_alloc() or key_alloc(),
as these only take KEY_ALLOC_* flags. KEY_FLAG_KEEP has the same value as
KEY_ALLOC_BYPASS_RESTRICTION, but fortunately only key_create_or_update()
uses it. LSMs using the key_alloc hook don't check that flag.
KEY_FLAG_KEEP is then ignored but fortunately (again) the root user cannot
write to the blacklist keyring, so it is not possible to remove a key/hash
from it.
Fix this by adding a KEY_ALLOC_SET_KEEP flag that tells key_alloc() to set
KEY_FLAG_KEEP on the new key. blacklist_init() can then, correctly, pass
this to keyring_alloc().
We can also use this in ima_mok_init() rather than setting the flag
manually.
Note that this doesn't fix an observable bug with the current
implementation but it is required to allow addition of new hashes to the
blacklist in the future without making it possible for them to be removed.
Fixes: 734114f878 ("KEYS: Add a system blacklist keyring")
Reported-by: Mickaël Salaün <mic@linux.microsoft.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Mickaël Salaün <mic@linux.microsoft.com>
cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f31e3386a4 ]
IMA allocates kernel virtual memory to carry forward the measurement
list, from the current kernel to the next kernel on kexec system call,
in ima_add_kexec_buffer() function. This buffer is not freed before
completing the kexec system call resulting in memory leak.
Add ima_buffer field in "struct kimage" to store the virtual address
of the buffer allocated for the IMA measurement list.
Free the memory allocated for the IMA measurement list in
kimage_file_post_load_cleanup() function.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Fixes: 7b8589cc29 ("ima: on soft reboot, save the measurement list")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6d14c65178 ]
IMA allocates kernel virtual memory to carry forward the measurement
list, from the current kernel to the next kernel on kexec system call,
in ima_add_kexec_buffer() function. In error code paths this memory
is not freed resulting in memory leak.
Free the memory allocated for the IMA measurement list in
the error code paths in ima_add_kexec_buffer() function.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Fixes: 7b8589cc29 ("ima: on soft reboot, save the measurement list")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 207cdd565d upstream.
Commit a408e4a86b ("ima: open a new file instance if no read
permissions") already introduced a second open to measure a file when the
original file descriptor does not allow it. However, it didn't remove the
existing method of changing the mode of the original file descriptor, which
is still necessary if the current process does not have enough privileges
to open a new one.
Changing the mode isn't really an option, as the filesystem might need to
do preliminary steps to make the read possible. Thus, this patch removes
the code and keeps the second open as the only option to measure a file
when it is unreadable with the original file descriptor.
Cc: <stable@vger.kernel.org> # 4.20.x: 0014cc04e8 ima: Set file->f_mode
Fixes: 2fe5d6def1 ("ima: integrity appraisal extension")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull integrity updates from Mimi Zohar:
"Continuing IMA policy rule cleanup and validation in particular for
measuring keys, adding/removing/updating informational and error
messages (e.g. "ima_appraise" boot command line option), and other bug
fixes (e.g. minimal data size validation before use, return code and
NULL pointer checking)"
* tag 'integrity-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: Fix NULL pointer dereference in ima_file_hash
evm: Check size of security.evm before using it
ima: Remove semicolon at the end of ima_get_binary_runtime_size()
ima: Don't ignore errors from crypto_shash_update()
ima: Use kmemdup rather than kmalloc+memcpy
integrity: include keyring name for unknown key request
ima: limit secure boot feedback scope for appraise
integrity: invalid kernel parameters feedback
ima: add check for enforced appraise option
integrity: Use current_uid() in integrity_audit_message()
ima: Fail rule parsing when asymmetric key measurement isn't supportable
ima: Pre-parse the list of keyrings in a KEY_CHECK rule
To perform partial reads, callers of kernel_read_file*() must have a
non-NULL file_size argument and a preallocated buffer. The new "offset"
argument can then be used to seek to specific locations in the file to
fill the buffer to, at most, "buf_size" per call.
Where possible, the LSM hooks can report whether a full file has been
read or not so that the contents can be reasoned about.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201002173828.2099543-14-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As with the kernel_load_data LSM hook, add a "contents" flag to the
kernel_read_file LSM hook that indicates whether the LSM can expect
a matching call to the kernel_post_read_file LSM hook with the full
contents of the file. With the coming addition of partial file read
support for kernel_read_file*() API, the LSM will no longer be able
to always see the entire contents of a file during the read calls.
For cases where the LSM must read examine the complete file contents,
it will need to do so on its own every time the kernel_read_file
hook is called with contents=false (or reject such cases). Adjust all
existing LSMs to retain existing behavior.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-12-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that security_post_load_data() is wired up, use it instead
of the NULL file argument style of security_post_read_file(),
and update the security_kernel_load_data() call to indicate that a
security_kernel_post_load_data() call is expected.
Wire up the IMA check to match earlier logic. Perhaps a generalized
change to ima_post_load_data() might look something like this:
return process_buffer_measurement(buf, size,
kernel_load_data_id_str(load_id),
read_idmap[load_id] ?: FILE_CHECK,
0, NULL);
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-10-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are a few places in the kernel where LSMs would like to have
visibility into the contents of a kernel buffer that has been loaded or
read. While security_kernel_post_read_file() (which includes the
buffer) exists as a pairing for security_kernel_read_file(), no such
hook exists to pair with security_kernel_load_data().
Earlier proposals for just using security_kernel_post_read_file() with a
NULL file argument were rejected (i.e. "file" should always be valid for
the security_..._file hooks, but it appears at least one case was
left in the kernel during earlier refactoring. (This will be fixed in
a subsequent patch.)
Since not all cases of security_kernel_load_data() can have a single
contiguous buffer made available to the LSM hook (e.g. kexec image
segments are separately loaded), there needs to be a way for the LSM to
reason about its expectations of the hook coverage. In order to handle
this, add a "contents" argument to the "kernel_load_data" hook that
indicates if the newly added "kernel_post_load_data" hook will be called
with the full contents once loaded. That way, LSMs requiring full contents
can choose to unilaterally reject "kernel_load_data" with contents=false
(which is effectively the existing hook coverage), but when contents=true
they can allow it and later evaluate the "kernel_post_load_data" hook
once the buffer is loaded.
With this change, LSMs can gain coverage over non-file-backed data loads
(e.g. init_module(2) and firmware userspace helper), which will happen
in subsequent patches.
Additionally prepare IMA to start processing these cases.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/r/20201002173828.2099543-9-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ima_file_hash can be called when there is no iint->ima_hash available
even though the inode exists in the integrity cache. It is fairly
common for a file to not have a hash. (e.g. an mknodat, prior to the
file being closed).
Another example where this can happen (suggested by Jann Horn):
Process A does:
while(1) {
unlink("/tmp/imafoo");
fd = open("/tmp/imafoo", O_RDWR|O_CREAT|O_TRUNC, 0700);
if (fd == -1) {
perror("open");
continue;
}
write(fd, "A", 1);
close(fd);
}
and Process B does:
while (1) {
int fd = open("/tmp/imafoo", O_RDONLY);
if (fd == -1)
continue;
char *mapping = mmap(NULL, 0x1000, PROT_READ|PROT_EXEC,
MAP_PRIVATE, fd, 0);
if (mapping != MAP_FAILED)
munmap(mapping, 0x1000);
close(fd);
}
Due to the race to get the iint->mutex between ima_file_hash and
process_measurement iint->ima_hash could still be NULL.
Fixes: 6beea7afcc ("ima: add the ability to query the cached hash of a given file")
Signed-off-by: KP Singh <kpsingh@google.com>
Reviewed-by: Florent Revest <revest@chromium.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This patch removes the unnecessary semicolon at the end of
ima_get_binary_runtime_size().
Cc: stable@vger.kernel.org
Fixes: d158847ae8 ("ima: maintain memory size needed for serializing the measurement list")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Errors returned by crypto_shash_update() are not checked in
ima_calc_boot_aggregate_tfm() and thus can be overwritten at the next
iteration of the loop. This patch adds a check after calling
crypto_shash_update() and returns immediately if the result is not zero.
Cc: stable@vger.kernel.org
Fixes: 3323eec921 ("integrity: IMA as an integrity service provider")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Only emit an unknown/invalid message when setting the IMA appraise mode
to anything other than "enforce", when secureboot is enabled.
Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
[zohar@linux.ibm.com: updated commit message]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The "enforce" string is allowed as an option for ima_appraise= kernel
paramenter per kernel-paramenters.txt and should be considered on the
parameter setup checking as a matter of completeness. Also it allows futher
checking on the options being passed by the user.
Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Measuring keys is currently only supported for asymmetric keys. In the
future, this might change.
For now, the "func=KEY_CHECK" and "keyrings=" options are only
appropriate when CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled. Make
this clear at policy load so that IMA policy authors don't assume that
these policy language constructs are supported.
Fixes: 2b60c0eced ("IMA: Read keyrings= option from the IMA policy")
Fixes: 5808611ccc ("IMA: Add KEY_CHECK func to measure keys")
Suggested-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The ima_keyrings buffer was used as a work buffer for strsep()-based
parsing of the "keyrings=" option of an IMA policy rule. This parsing
was re-performed each time an asymmetric key was added to a kernel
keyring for each loaded policy rule that contained a "keyrings=" option.
An example rule specifying this option is:
measure func=KEY_CHECK keyrings=a|b|c
The rule says to measure asymmetric keys added to any of the kernel
keyrings named "a", "b", or "c". The size of the buffer size was
equal to the size of the largest "keyrings=" value seen in a previously
loaded rule (5 + 1 for the NUL-terminator in the previous example) and
the buffer was pre-allocated at the time of policy load.
The pre-allocated buffer approach suffered from a couple bugs:
1) There was no locking around the use of the buffer so concurrent key
add operations, to two different keyrings, would result in the
strsep() loop of ima_match_keyring() to modify the buffer at the same
time. This resulted in unexpected results from ima_match_keyring()
and, therefore, could cause unintended keys to be measured or keys to
not be measured when IMA policy intended for them to be measured.
2) If the kstrdup() that initialized entry->keyrings in ima_parse_rule()
failed, the ima_keyrings buffer was freed and set to NULL even when a
valid KEY_CHECK rule was previously loaded. The next KEY_CHECK event
would trigger a call to strcpy() with a NULL destination pointer and
crash the kernel.
Remove the need for a pre-allocated global buffer by parsing the list of
keyrings in a KEY_CHECK rule at the time of policy load. The
ima_rule_entry will contain an array of string pointers which point to
the name of each keyring specified in the rule. No string processing
needs to happen at the time of asymmetric key add so iterating through
the list and doing a string comparison is all that's required at the
time of policy check.
In the process of changing how the "keyrings=" policy option is handled,
a couple additional bugs were fixed:
1) The rule parser accepted rules containing invalid "keyrings=" values
such as "a|b||c", "a|b|", or simply "|".
2) The /sys/kernel/security/ima/policy file did not display the entire
"keyrings=" value if the list of keyrings was longer than what could
fit in the fixed size tbuf buffer in ima_policy_show().
Fixes: 5c7bac9fb2 ("IMA: pre-allocate buffer to hold keyrings string")
Fixes: 2b60c0eced ("IMA: Read keyrings= option from the IMA policy")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Pull security subsystem updates from James Morris:
"A couple of minor documentation updates only for this release"
* tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
LSM: drop duplicated words in header file comments
Replace HTTP links with HTTPS ones: security
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
The IMA_APPRAISE_BOOTPARAM config allows enabling different "ima_appraise="
modes - log, fix, enforce - at run time, but not when IMA architecture
specific policies are enabled. This prevents properly labeling the
filesystem on systems where secure boot is supported, but not enabled on the
platform. Only when secure boot is actually enabled should these IMA
appraise modes be disabled.
This patch removes the compile time dependency and makes it a runtime
decision, based on the secure boot state of that platform.
Test results as follows:
-> x86-64 with secure boot enabled
[ 0.015637] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix
[ 0.015668] ima: Secure boot enabled: ignoring ima_appraise=fix boot parameter option
-> powerpc with secure boot disabled
[ 0.000000] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix
[ 0.000000] Secure boot mode disabled
-> Running the system without secure boot and with both options set:
CONFIG_IMA_APPRAISE_BOOTPARAM=y
CONFIG_IMA_ARCH_POLICY=y
Audit prompts "missing-hash" but still allow execution and, consequently,
filesystem labeling:
type=INTEGRITY_DATA msg=audit(07/09/2020 12:30:27.778:1691) : pid=4976
uid=root auid=root ses=2
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 op=appraise_data
cause=missing-hash comm=bash name=/usr/bin/evmctl dev="dm-0" ino=493150
res=no
Cc: stable@vger.kernel.org
Fixes: d958083a8f ("x86/ima: define arch_get_ima_policy() for x86")
Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
Cc: stable@vger.kernel.org # 5.0
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Arnd Bergmann