19 Jul, 2011

9 commits

  • Initialize 'security.evm' for new files.

    Changelog v7:
    - renamed evm_inode_post_init_security to evm_inode_init_security
    - moved struct xattr definition to earlier patch
    - allocate xattr name
    Changelog v6:
    - Use 'struct evm_ima_xattr_data'

    Signed-off-by: Mimi Zohar

    Mimi Zohar
     
  • Changing the inode's metadata may require the 'security.evm' extended
    attribute to be re-calculated and updated.

    Signed-off-by: Mimi Zohar
    Acked-by: Serge Hallyn

    Mimi Zohar
     
  • When an EVM protected extended attribute is removed, update 'security.evm'.

    Signed-off-by: Mimi Zohar
    Acked-by: Serge Hallyn

    Mimi Zohar
     
  • Imbed the evm calls evm_inode_setxattr(), evm_inode_post_setxattr(),
    evm_inode_removexattr() in the security hooks. evm_inode_setxattr()
    protects security.evm xattr. evm_inode_post_setxattr() and
    evm_inode_removexattr() updates the hmac associated with an inode.

    (Assumes an LSM module protects the setting/removing of xattr.)

    Changelog:
    - Don't define evm_verifyxattr(), unless CONFIG_INTEGRITY is enabled.
    - xattr_name is a 'const', value is 'void *'

    Signed-off-by: Mimi Zohar
    Acked-by: Serge Hallyn

    Mimi Zohar
     
  • EVM protects a file's security extended attributes(xattrs) against integrity
    attacks. The current patchset maintains an HMAC-sha1 value across the security
    xattrs, storing the value as the extended attribute 'security.evm'. We
    anticipate other methods for protecting the security extended attributes.
    This patch reserves the first byte of 'security.evm' as a place holder for
    the type of method.

    Changelog v6:
    - move evm_ima_xattr_type definition to security/integrity/integrity.h
    - defined a structure for the EVM xattr called evm_ima_xattr_data
    (based on Serge Hallyn's suggestion)
    - removed unnecessary memset

    Signed-off-by: Dmitry Kasatkin
    Signed-off-by: Mimi Zohar
    Acked-by: Serge Hallyn

    Dmitry Kasatkin
     
  • EVM protects a file's security extended attributes(xattrs) against integrity
    attacks. This patchset provides the framework and an initial method. The
    initial method maintains an HMAC-sha1 value across the security extended
    attributes, storing the HMAC value as the extended attribute 'security.evm'.
    Other methods of validating the integrity of a file's metadata will be posted
    separately (eg. EVM-digital-signatures).

    While this patchset does authenticate the security xattrs, and
    cryptographically binds them to the inode, coming extensions will bind other
    directory and inode metadata for more complete protection. To help simplify
    the review and upstreaming process, each extension will be posted separately
    (eg. IMA-appraisal, IMA-appraisal-directory). For a general overview of the
    proposed Linux integrity subsystem, refer to Dave Safford's whitepaper:
    http://downloads.sf.net/project/linux-ima/linux-ima/Integrity_overview.pdf.

    EVM depends on the Kernel Key Retention System to provide it with a
    trusted/encrypted key for the HMAC-sha1 operation. The key is loaded onto the
    root's keyring using keyctl. Until EVM receives notification that the key has
    been successfully loaded onto the keyring (echo 1 > /evm), EVM can
    not create or validate the 'security.evm' xattr, but returns INTEGRITY_UNKNOWN.
    Loading the key and signaling EVM should be done as early as possible. Normally
    this is done in the initramfs, which has already been measured as part of the
    trusted boot. For more information on creating and loading existing
    trusted/encrypted keys, refer to Documentation/keys-trusted-encrypted.txt. A
    sample dracut patch, which loads the trusted/encrypted key and enables EVM, is
    available from http://linux-ima.sourceforge.net/#EVM.

    Based on the LSMs enabled, the set of EVM protected security xattrs is defined
    at compile. EVM adds the following three calls to the existing security hooks:
    evm_inode_setxattr(), evm_inode_post_setxattr(), and evm_inode_removexattr. To
    initialize and update the 'security.evm' extended attribute, EVM defines three
    calls: evm_inode_post_init(), evm_inode_post_setattr() and
    evm_inode_post_removexattr() hooks. To verify the integrity of a security
    xattr, EVM exports evm_verifyxattr().

    Changelog v7:
    - Fixed URL in EVM ABI documentation

    Changelog v6: (based on Serge Hallyn's review)
    - fix URL in patch description
    - remove evm_hmac_size definition
    - use SHA1_DIGEST_SIZE (removed both MAX_DIGEST_SIZE and evm_hmac_size)
    - moved linux include before other includes
    - test for crypto_hash_setkey failure
    - fail earlier for invalid key
    - clear entire encrypted key, even on failure
    - check xattr name length before comparing xattr names

    Changelog:
    - locking based on i_mutex, remove evm_mutex
    - using trusted/encrypted keys for storing the EVM key used in the HMAC-sha1
    operation.
    - replaced crypto hash with shash (Dmitry Kasatkin)
    - support for additional methods of verifying the security xattrs
    (Dmitry Kasatkin)
    - iint not allocated for all regular files, but only for those appraised
    - Use cap_sys_admin in lieu of cap_mac_admin
    - Use __vfs_setxattr_noperm(), without permission checks, from EVM

    Signed-off-by: Mimi Zohar
    Acked-by: Serge Hallyn

    Mimi Zohar
     
  • vfs_getxattr_alloc() and vfs_xattr_cmp() are two new kernel xattr helper
    functions. vfs_getxattr_alloc() first allocates memory for the requested
    xattr and then retrieves it. vfs_xattr_cmp() compares a given value with
    the contents of an extended attribute.

    Signed-off-by: Mimi Zohar
    Acked-by: Serge Hallyn

    Mimi Zohar
     
  • Move the inode integrity data(iint) management up to the integrity directory
    in order to share the iint among the different integrity models.

    Changelog:
    - don't define MAX_DIGEST_SIZE
    - rename several globally visible 'ima_' prefixed functions, structs,
    locks, etc to 'integrity_'
    - replace '20' with SHA1_DIGEST_SIZE
    - reflect location change in appropriate Kconfig and Makefiles
    - remove unnecessary initialization of iint_initialized to 0
    - rebased on current ima_iint.c
    - define integrity_iint_store/lock as static

    There should be no other functional changes.

    Signed-off-by: Mimi Zohar
    Acked-by: Serge Hallyn

    Mimi Zohar
     
  • This patch changes the security_inode_init_security API by adding a
    filesystem specific callback to write security extended attributes.
    This change is in preparation for supporting the initialization of
    multiple LSM xattrs and the EVM xattr. Initially the callback function
    walks an array of xattrs, writing each xattr separately, but could be
    optimized to write multiple xattrs at once.

    For existing security_inode_init_security() calls, which have not yet
    been converted to use the new callback function, such as those in
    reiserfs and ocfs2, this patch defines security_old_inode_init_security().

    Signed-off-by: Mimi Zohar

    Mimi Zohar
     

14 Jul, 2011

1 commit


13 Jul, 2011

12 commits

  • This patch fixes a typo.

    Signed-off-by: Stefan Berger
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • This patch introduces a function for automatic probing for the Intel iTPM
    STS_DATA_EXPECT flaw.

    The patch splits the current tpm_tis_send function into 2 parts where the 1st
    part is now called tpm_tis_send_data() and merely sends the data to the TPM.
    This function is then used for probing. The new tpm_tis_send function now
    first calls tpm_tis_send_data and if that succeeds has the TPM process the
    command and waits until the response is there.

    The probing for the Intel iTPM is only invoked if the user has not passed
    itpm=1 as parameter for the module *or* if such a TPM was detected via ACPI.
    Previously it was necessary to pass itpm=1 when also passing force=1 to the
    module when doing a 'modprobe'. This function is more general than the ACPI
    test function and the function relying on ACPI could probably be removed.

    Signed-off-by: Stefan Berger
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • This patch fixes several aspects of the probing for interrupts.

    This patch reads the TPM's timeouts before probing for the interrupts. The
    tpm_get_timeouts() function is invoked in polling mode and gets the proper
    timeouts from the TPM so that we don't need to fall back to 2 minutes timeouts
    for short duration commands while the interrupt probing is happening.

    This patch introduces a variable probed_irq into the vendor structure that gets
    the irq number if an interrupt is received while the the tpm_gen_interrupt()
    function is run in polling mode during interrupt probing. Previously some
    parts of tpm_gen_interrupt() were run in polling mode, then the irq variable
    was set in the interrupt handler when an interrupt was received and execution
    of tpm_gen_interrupt() ended up switching over to interrupt mode.
    tpm_gen_interrupt() execution ended up on an event queue where it eventually
    timed out since the probing handler doesn't wake any queues.

    Before calling into free_irq() clear all interrupt flags that may have
    been set by the TPM. The reason is that free_irq() will call into the probing
    interrupt handler and may otherwise fool us into thinking that a real interrupt
    happened (because we see the flags as being set) while the TPM's interrupt line
    is not even connected to anything on the motherboard. This solves a problem
    on one machine I did testing on (Thinkpad T60).

    If a TPM claims to use a specifc interrupt, the probing is done as well
    to verify that the interrupt is actually working. If a TPM indicates
    that it does not use a specific interrupt (returns '0'), probe all interrupts
    from 3 to 15.

    Signed-off-by: Stefan Berger
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • This patch delays the (ACPI S3) suspend while the TPM is busy processing a
    command and the TPM TIS driver is run in interrupt mode. This is the same
    behavior as we already have it for the TPM TIS driver in polling mode.

    Reasoning: Some of the TPM's commands advance the internal state of the TPM.
    An example would be the extending of one of its PCR registers. Upper layers,
    such as IMA or TSS (TrouSerS), would certainly want to be sure that the
    command succeeded rather than getting an error code (-62 = -ETIME) that may
    not give a conclusive answer as for what reason the command failed. Reissuing
    such a command would put the TPM into the wrong state, so waiting for it to
    finish is really the only option.

    The downside is that some commands (key creation) can take a long time and
    actually prevent the machine from entering S3 at all before the 20 second
    timeout of the power management subsystem arrives.

    Signed-off-by: Stefan Berger
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • This patch makes sure that if the TPM TIS interface is run in interrupt mode
    (rather than polling mode) that all interrupts are enabled in the TPM's
    interrupt enable register after a resume from ACPI S3 suspend. The registers
    may either have been cleared by the TPM loosing its state during device sleep
    or by the BIOS leaving the TPM in polling mode (after sending a command to
    the TPM for starting it up again)

    You may want to check if your TPM runs with interrupts by doing

    cat /proc/interrupts | grep -i tpm

    and see whether there is an entry or otherwise for it to use interrupts:

    modprobe tpm_tis interrupts=1 [add 'itpm=1' for Intel TPM ]

    v2:
    - the patch was adapted to work with the pnp and platform driver
    implementations in tpm_tis.c

    Signed-off-by: Stefan Berger
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • This patch fixes the TPM's pubek sysfs entry that is accessible as long
    as the TPM doesn't have an owner. It was necessary to shift the access to the
    data by -10 -- the first byte immediately follows the 10 byte header. The
    line

    data = tpm_cmd.params.readpubek_out_buffer;

    sets it at the offset '10' in the packet, so we can read the data array
    starting at offset '0'.

    Before:

    Algorithm: 00 0C 00 00
    Encscheme: 08 00
    Sigscheme: 00 00
    Parameters: 00 00 00 00 01 00 AC E2 5E 3C A0 78
    Modulus length: -563306801
    Modulus:
    28 21 08 0F 82 CD F2 B1 E7 49 F7 74 70 BE 59 8C
    43 78 B1 24 EA 52 E2 FE 52 5C 3A 12 3B DC 61 71
    [...]

    After:

    Algorithm: 00 00 00 01
    Encscheme: 00 03
    Sigscheme: 00 01
    Parameters: 00 00 08 00 00 00 00 02 00 00 00 00
    Modulus length: 256
    Modulus:
    AC E2 5E 3C A0 78 DE 6C 9E CF 28 21 08 0F 82 CD
    F2 B1 E7 49 F7 74 70 BE 59 8C 43 78 B1 24 EA 52
    [...]

    Signed-off-by: Stefan Berger
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • Display the TPM's interface timeouts in a 'timeouts' sysfs entry. Display
    the entries as having been adjusted when they were scaled due to their values
    being reported in milliseconds rather than microseconds.

    Signed-off-by: Stefan Berger
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • Adjust the interface timeouts if they are found to be too small, i.e., if
    they are returned in milliseconds rather than microseconds as we heared
    from Infineon that some (old) Infineon TPMs do.

    Signed-off-by: Stefan Berger
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • The TPM driver currently discards the interface timeout values returned
    from the TPM. The check of the response packet needs to consider that
    the return_code field is 0 on success and the size of the expected
    packet is equivalent to the header size + u32 length indicator for the
    TPM_GetCapability() result + 4 interface timeout indicators of type u32.

    Signed-off-by: Stefan Berger
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • Display the TPM's command timeouts in a 'durations' sysfs entry. Display
    the entries as having been adjusted when they were scaled due to their values
    being reported in milliseconds rather than microseconds.

    Signed-off-by: Stefan Berger
    Tested-by: Guillaume Chazarain
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • Adjust the durations if they are found to be too small, i.e., if they are
    returned in milliseconds rather than microseconds as some Infineon TPMs are
    reported to do.

    Signed-off-by: Stefan Berger
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     
  • The TPM driver currently discards the durations values returned
    from the TPM. The check of the response packet needs to consider that
    the return_code field is 0 on success and the size of the expected
    packet is equivalent to the header size + u32 length indicator for the
    TPM_GetCapability() result + 3 timeout indicators of type u32.

    v4:
    - sysfs entry 'durations' is now a patch of its own
    - the work-around for TPMs reporting durations in milliseconds is now in a
    patch of its own

    v3:
    - sysfs entry now called 'durations' to resemble TPM-speak (previously
    was called 'timeouts')

    v2:
    - adjusting all timeouts for TPM devices reporting timeouts in msec rather
    than usec
    - also displaying in sysfs whether the timeouts are 'original' or 'adjusted'

    Signed-off-by: Stefan Berger
    Tested-by: Guillaume Chazarain
    Signed-off-by: Rajiv Andrade

    Stefan Berger
     

11 Jul, 2011

5 commits


08 Jul, 2011

1 commit


01 Jul, 2011

1 commit


30 Jun, 2011

10 commits


29 Jun, 2011

1 commit

  • pca954x power-on default is channel 0 connected. If multiple pca954x
    muxes are connected to the same physical I2C bus, the parent bus will
    see channel 0 devices behind both muxes by default. This is bad.

    Scenario:
    -- pca954x @ 0x70 -- ch 0 (I2C-bus-101) -- EEPROM @ 0x50
    |
    I2C-bus-1 ---
    |
    -- pca954x @ 0x71 -- ch 0 (I2C-bus-111) -- EEPROM @ 0x50

    1. Load I2C bus driver: creates I2C-bus-1
    2. Load pca954x driver: creates virtual I2C-bus-101 and I2C-bus-111
    3. Load eeprom driver
    4. Try to read EEPROM @ 0x50 on I2C-bus-101. The transaction will also bleed
    onto I2C-bus-111 because pca954x @ 0x71 channel 0 is connected by default.

    Fix: Initialize pca954x to disconnected state in pca954x_probe()

    Signed-off-by: Petri Gynther
    Signed-off-by: Jean Delvare
    Cc: stable@kernel.org

    Petri Gynther