<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/security/integrity/ima, branch v4.19</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security</title>
<updated>2018-08-16T05:54:12+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-08-16T05:54:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f91e654474d413201ae578820fb63f8a811f6c4e'/>
<id>f91e654474d413201ae578820fb63f8a811f6c4e</id>
<content type='text'>
Pull integrity updates from James Morris:
 "This adds support for EVM signatures based on larger digests, contains
  a new audit record AUDIT_INTEGRITY_POLICY_RULE to differentiate the
  IMA policy rules from the IMA-audit messages, addresses two deadlocks
  due to either loading or searching for crypto algorithms, and cleans
  up the audit messages"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  EVM: fix return value check in evm_write_xattrs()
  integrity: prevent deadlock during digsig verification.
  evm: Allow non-SHA1 digital signatures
  evm: Don't deadlock if a crypto algorithm is unavailable
  integrity: silence warning when CONFIG_SECURITYFS is not enabled
  ima: Differentiate auditing policy rules from "audit" actions
  ima: Do not audit if CONFIG_INTEGRITY_AUDIT is not set
  ima: Use audit_log_format() rather than audit_log_string()
  ima: Call audit_log_string() rather than logging it untrusted
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull integrity updates from James Morris:
 "This adds support for EVM signatures based on larger digests, contains
  a new audit record AUDIT_INTEGRITY_POLICY_RULE to differentiate the
  IMA policy rules from the IMA-audit messages, addresses two deadlocks
  due to either loading or searching for crypto algorithms, and cleans
  up the audit messages"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  EVM: fix return value check in evm_write_xattrs()
  integrity: prevent deadlock during digsig verification.
  evm: Allow non-SHA1 digital signatures
  evm: Don't deadlock if a crypto algorithm is unavailable
  integrity: silence warning when CONFIG_SECURITYFS is not enabled
  ima: Differentiate auditing policy rules from "audit" actions
  ima: Do not audit if CONFIG_INTEGRITY_AUDIT is not set
  ima: Use audit_log_format() rather than audit_log_string()
  ima: Call audit_log_string() rather than logging it untrusted
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security</title>
<updated>2018-08-16T05:51:12+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-08-16T05:51:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c715ebeb0303b196f17376f189ae4e168d98b563'/>
<id>c715ebeb0303b196f17376f189ae4e168d98b563</id>
<content type='text'>
Pull TPM updates from James Morris:

 - Migrate away from PM runtime as explicit cmdReady/goIdle transactions
   for every command is a spec requirement. PM runtime adds only a layer
   of complexity on our case.

 - tpm_tis drivers can now specify the hwrng quality.

 - TPM 2.0 code uses now tpm_buf for constructing messages. Jarkko
   thinks Tomas Winkler has done the same for TPM 1.2, and will start
   digging those changes from the patchwork in the near future.

 - Bug fixes and clean ups

* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  ima: Get rid of ima_used_chip and use ima_tpm_chip != NULL instead
  ima: Use tpm_default_chip() and call TPM functions with a tpm_chip
  tpm: replace TPM_TRANSMIT_RAW with TPM_TRANSMIT_NESTED
  tpm: Convert tpm_find_get_ops() to use tpm_default_chip()
  tpm: Implement tpm_default_chip() to find a TPM chip
  tpm: rename tpm_chip_find_get() to tpm_find_get_ops()
  tpm: Allow tpm_tis drivers to set hwrng quality.
  tpm: Return the actual size when receiving an unsupported command
  tpm: separate cmd_ready/go_idle from runtime_pm
  tpm/tpm_i2c_infineon: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)
  tpm_tis_spi: Pass the SPI IRQ down to the driver
  tpm: migrate tpm2_get_random() to use struct tpm_buf
  tpm: migrate tpm2_get_tpm_pt() to use struct tpm_buf
  tpm: migrate tpm2_probe() to use struct tpm_buf
  tpm: migrate tpm2_shutdown() to use struct tpm_buf
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull TPM updates from James Morris:

 - Migrate away from PM runtime as explicit cmdReady/goIdle transactions
   for every command is a spec requirement. PM runtime adds only a layer
   of complexity on our case.

 - tpm_tis drivers can now specify the hwrng quality.

 - TPM 2.0 code uses now tpm_buf for constructing messages. Jarkko
   thinks Tomas Winkler has done the same for TPM 1.2, and will start
   digging those changes from the patchwork in the near future.

 - Bug fixes and clean ups

* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  ima: Get rid of ima_used_chip and use ima_tpm_chip != NULL instead
  ima: Use tpm_default_chip() and call TPM functions with a tpm_chip
  tpm: replace TPM_TRANSMIT_RAW with TPM_TRANSMIT_NESTED
  tpm: Convert tpm_find_get_ops() to use tpm_default_chip()
  tpm: Implement tpm_default_chip() to find a TPM chip
  tpm: rename tpm_chip_find_get() to tpm_find_get_ops()
  tpm: Allow tpm_tis drivers to set hwrng quality.
  tpm: Return the actual size when receiving an unsupported command
  tpm: separate cmd_ready/go_idle from runtime_pm
  tpm/tpm_i2c_infineon: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)
  tpm_tis_spi: Pass the SPI IRQ down to the driver
  tpm: migrate tpm2_get_random() to use struct tpm_buf
  tpm: migrate tpm2_get_tpm_pt() to use struct tpm_buf
  tpm: migrate tpm2_probe() to use struct tpm_buf
  tpm: migrate tpm2_shutdown() to use struct tpm_buf
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security</title>
<updated>2018-08-15T17:25:26+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-08-15T17:25:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=92d4a03674b8c399c2f547580fa509db78226170'/>
<id>92d4a03674b8c399c2f547580fa509db78226170</id>
<content type='text'>
Pull security subsystem updates from James Morris:

 - kstrdup() return value fix from Eric Biggers

 - Add new security_load_data hook to differentiate security checking of
   kernel-loaded binaries in the case of there being no associated file
   descriptor, from Mimi Zohar.

 - Add ability to IMA to specify a policy at build-time, rather than
   just via command line params or by loading a custom policy, from
   Mimi.

 - Allow IMA and LSMs to prevent sysfs firmware load fallback (e.g. if
   using signed firmware), from Mimi.

 - Allow IMA to deny loading of kexec kernel images, as they cannot be
   measured by IMA, from Mimi.

* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  security: check for kstrdup() failure in lsm_append()
  security: export security_kernel_load_data function
  ima: based on policy warn about loading firmware (pre-allocated buffer)
  module: replace the existing LSM hook in init_module
  ima: add build time policy
  ima: based on policy require signed firmware (sysfs fallback)
  firmware: add call to LSM hook before firmware sysfs fallback
  ima: based on policy require signed kexec kernel images
  kexec: add call to LSM hook in original kexec_load syscall
  security: define new LSM hook named security_kernel_load_data
  MAINTAINERS: remove the outdated "LINUX SECURITY MODULE (LSM) FRAMEWORK" entry
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull security subsystem updates from James Morris:

 - kstrdup() return value fix from Eric Biggers

 - Add new security_load_data hook to differentiate security checking of
   kernel-loaded binaries in the case of there being no associated file
   descriptor, from Mimi Zohar.

 - Add ability to IMA to specify a policy at build-time, rather than
   just via command line params or by loading a custom policy, from
   Mimi.

 - Allow IMA and LSMs to prevent sysfs firmware load fallback (e.g. if
   using signed firmware), from Mimi.

 - Allow IMA to deny loading of kexec kernel images, as they cannot be
   measured by IMA, from Mimi.

* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  security: check for kstrdup() failure in lsm_append()
  security: export security_kernel_load_data function
  ima: based on policy warn about loading firmware (pre-allocated buffer)
  module: replace the existing LSM hook in init_module
  ima: add build time policy
  ima: based on policy require signed firmware (sysfs fallback)
  firmware: add call to LSM hook before firmware sysfs fallback
  ima: based on policy require signed kexec kernel images
  kexec: add call to LSM hook in original kexec_load syscall
  security: define new LSM hook named security_kernel_load_data
  MAINTAINERS: remove the outdated "LINUX SECURITY MODULE (LSM) FRAMEWORK" entry
</pre>
</div>
</content>
</entry>
<entry>
<title>ima: Get rid of ima_used_chip and use ima_tpm_chip != NULL instead</title>
<updated>2018-07-28T14:03:11+00:00</updated>
<author>
<name>Stefan Berger</name>
<email>stefanb@linux.vnet.ibm.com</email>
</author>
<published>2018-06-26T19:09:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ec403d8ed08c8272cfeeeea154fdebcd289988c8'/>
<id>ec403d8ed08c8272cfeeeea154fdebcd289988c8</id>
<content type='text'>
Get rid of ima_used_chip and use ima_tpm_chip variable instead for
determining whether to use the TPM chip.

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
Reviewed-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
Signed-off-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Get rid of ima_used_chip and use ima_tpm_chip variable instead for
determining whether to use the TPM chip.

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
Reviewed-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
Signed-off-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ima: Use tpm_default_chip() and call TPM functions with a tpm_chip</title>
<updated>2018-07-28T14:03:11+00:00</updated>
<author>
<name>Stefan Berger</name>
<email>stefanb@linux.vnet.ibm.com</email>
</author>
<published>2018-06-26T19:09:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5c2a640aff73914e11ac0db310b32d3b7a1b87ad'/>
<id>5c2a640aff73914e11ac0db310b32d3b7a1b87ad</id>
<content type='text'>
Rather than accessing the TPM functions by passing a NULL pointer for
the tpm_chip, which causes a lookup for a suitable chip every time, get a
hold of a tpm_chip and access the TPM functions using it.

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
Reviewed-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
Signed-off-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rather than accessing the TPM functions by passing a NULL pointer for
the tpm_chip, which causes a lookup for a suitable chip every time, get a
hold of a tpm_chip and access the TPM functions using it.

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
Reviewed-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
Signed-off-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ima: Differentiate auditing policy rules from "audit" actions</title>
<updated>2018-07-18T11:27:22+00:00</updated>
<author>
<name>Stefan Berger</name>
<email>stefanb@linux.vnet.ibm.com</email>
</author>
<published>2018-06-04T20:54:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dba31ee759417ef1a952e929524b0cca1751c036'/>
<id>dba31ee759417ef1a952e929524b0cca1751c036</id>
<content type='text'>
The AUDIT_INTEGRITY_RULE is used for auditing IMA policy rules and
the IMA "audit" policy action.  This patch defines
AUDIT_INTEGRITY_POLICY_RULE to reflect the IMA policy rules.

Since we defined a new message type we can now also pass the
audit_context and get an associated SYSCALL record. This now produces
the following records when parsing IMA policy's rules:

type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
  func=MMAP_CHECK mask=MAY_EXEC res=1
type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
  func=FILE_CHECK mask=MAY_READ res=1
type=SYSCALL msg=audit(1527888965.738:320): arch=c000003e syscall=1 \
  success=yes exit=17 a0=1 a1=55bcfcca9030 a2=11 a3=7fcc1b55fb38 \
  items=0 ppid=1567 pid=1601 auid=0 uid=0 gid=0 euid=0 suid=0 \
  fsuid=0 egid=0 sgid=0 fsgid=0 tty=tty2 ses=2 comm="echo" \
  exe="/usr/bin/echo" \
  subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The AUDIT_INTEGRITY_RULE is used for auditing IMA policy rules and
the IMA "audit" policy action.  This patch defines
AUDIT_INTEGRITY_POLICY_RULE to reflect the IMA policy rules.

Since we defined a new message type we can now also pass the
audit_context and get an associated SYSCALL record. This now produces
the following records when parsing IMA policy's rules:

type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
  func=MMAP_CHECK mask=MAY_EXEC res=1
type=UNKNOWN[1807] msg=audit(1527888965.738:320): action=audit \
  func=FILE_CHECK mask=MAY_READ res=1
type=SYSCALL msg=audit(1527888965.738:320): arch=c000003e syscall=1 \
  success=yes exit=17 a0=1 a1=55bcfcca9030 a2=11 a3=7fcc1b55fb38 \
  items=0 ppid=1567 pid=1601 auid=0 uid=0 gid=0 euid=0 suid=0 \
  fsuid=0 egid=0 sgid=0 fsgid=0 tty=tty2 ses=2 comm="echo" \
  exe="/usr/bin/echo" \
  subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ima: Do not audit if CONFIG_INTEGRITY_AUDIT is not set</title>
<updated>2018-07-18T11:27:22+00:00</updated>
<author>
<name>Stefan Berger</name>
<email>stefanb@linux.vnet.ibm.com</email>
</author>
<published>2018-06-04T20:54:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2afd020aaeeefacb7711b47e3afb0cfb50db3f13'/>
<id>2afd020aaeeefacb7711b47e3afb0cfb50db3f13</id>
<content type='text'>
If Integrity is not auditing, IMA shouldn't audit, either.

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If Integrity is not auditing, IMA shouldn't audit, either.

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ima: Use audit_log_format() rather than audit_log_string()</title>
<updated>2018-07-18T11:27:22+00:00</updated>
<author>
<name>Stefan Berger</name>
<email>stefanb@linux.vnet.ibm.com</email>
</author>
<published>2018-06-04T20:54:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3d2859d5d4c33b12327764b887039bca15a37e57'/>
<id>3d2859d5d4c33b12327764b887039bca15a37e57</id>
<content type='text'>
Remove the usage of audit_log_string() and replace it with
audit_log_format().

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Suggested-by: Steve Grubb &lt;sgrubb@redhat.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove the usage of audit_log_string() and replace it with
audit_log_format().

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Suggested-by: Steve Grubb &lt;sgrubb@redhat.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ima: Call audit_log_string() rather than logging it untrusted</title>
<updated>2018-07-18T11:27:22+00:00</updated>
<author>
<name>Stefan Berger</name>
<email>stefanb@linux.vnet.ibm.com</email>
</author>
<published>2018-06-04T20:54:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8a3bcaf6ecd37fee326cd30732192ef2a09e5b07'/>
<id>8a3bcaf6ecd37fee326cd30732192ef2a09e5b07</id>
<content type='text'>
The parameters passed to this logging function are all provided by
a privileged user and therefore we can call audit_log_string()
rather than audit_log_untrustedstring().

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Suggested-by: Steve Grubb &lt;sgrubb@redhat.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The parameters passed to this logging function are all provided by
a privileged user and therefore we can call audit_log_string()
rather than audit_log_untrustedstring().

Signed-off-by: Stefan Berger &lt;stefanb@linux.vnet.ibm.com&gt;
Suggested-by: Steve Grubb &lt;sgrubb@redhat.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ima: based on policy warn about loading firmware (pre-allocated buffer)</title>
<updated>2018-07-16T19:31:57+00:00</updated>
<author>
<name>Mimi Zohar</name>
<email>zohar@linux.vnet.ibm.com</email>
</author>
<published>2018-07-13T18:06:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4f0496d8ffa3ed5956a2ddee5d84f0246977799d'/>
<id>4f0496d8ffa3ed5956a2ddee5d84f0246977799d</id>
<content type='text'>
Some systems are memory constrained but they need to load very large
firmwares.  The firmware subsystem allows drivers to request this
firmware be loaded from the filesystem, but this requires that the
entire firmware be loaded into kernel memory first before it's provided
to the driver.  This can lead to a situation where we map the firmware
twice, once to load the firmware into kernel memory and once to copy the
firmware into the final resting place.

To resolve this problem, commit a098ecd2fa7d ("firmware: support loading
into a pre-allocated buffer") introduced request_firmware_into_buf() API
that allows drivers to request firmware be loaded directly into a
pre-allocated buffer.

Do devices using pre-allocated memory run the risk of the firmware being
accessible to the device prior to the completion of IMA's signature
verification any more than when using two buffers? (Refer to mailing list
discussion[1]).

Only on systems with an IOMMU can the access be prevented.  As long as
the signature verification completes prior to the DMA map is performed,
the device can not access the buffer.  This implies that the same buffer
can not be re-used.  Can we ensure the buffer has not been DMA mapped
before using the pre-allocated buffer?

[1] https://lkml.org/lkml/2018/7/10/56

Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
Cc: Luis R. Rodriguez &lt;mcgrof@suse.com&gt;
Cc: Stephen Boyd &lt;sboyd@kernel.org&gt;
Cc: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: James Morris &lt;james.morris@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some systems are memory constrained but they need to load very large
firmwares.  The firmware subsystem allows drivers to request this
firmware be loaded from the filesystem, but this requires that the
entire firmware be loaded into kernel memory first before it's provided
to the driver.  This can lead to a situation where we map the firmware
twice, once to load the firmware into kernel memory and once to copy the
firmware into the final resting place.

To resolve this problem, commit a098ecd2fa7d ("firmware: support loading
into a pre-allocated buffer") introduced request_firmware_into_buf() API
that allows drivers to request firmware be loaded directly into a
pre-allocated buffer.

Do devices using pre-allocated memory run the risk of the firmware being
accessible to the device prior to the completion of IMA's signature
verification any more than when using two buffers? (Refer to mailing list
discussion[1]).

Only on systems with an IOMMU can the access be prevented.  As long as
the signature verification completes prior to the DMA map is performed,
the device can not access the buffer.  This implies that the same buffer
can not be re-used.  Can we ensure the buffer has not been DMA mapped
before using the pre-allocated buffer?

[1] https://lkml.org/lkml/2018/7/10/56

Signed-off-by: Mimi Zohar &lt;zohar@linux.vnet.ibm.com&gt;
Cc: Luis R. Rodriguez &lt;mcgrof@suse.com&gt;
Cc: Stephen Boyd &lt;sboyd@kernel.org&gt;
Cc: Bjorn Andersson &lt;bjorn.andersson@linaro.org&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: James Morris &lt;james.morris@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
