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  1. 28 7月, 2020 1 次提交
  3. 21 7月, 2020 9 次提交
    • B
      ima: move APPRAISE_BOOTPARAM dependency on ARCH_POLICY to runtime · 311aa6aa
      由 Bruno Meneguele 提交于 
      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: d958083a ("x86/ima: define arch_get_ima_policy() for x86")
Signed-off-by: NBruno Meneguele <bmeneg@redhat.com>
Cc: stable@vger.kernel.org # 5.0
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      311aa6aa
    • T
      ima: AppArmor satisfies the audit rule requirements · 1768215a
      由 Tyler Hicks 提交于 
      AppArmor meets all the requirements for IMA in terms of audit rules
since commit e79c26d0 ("apparmor: Add support for audit rule
filtering"). Update IMA's Kconfig section for CONFIG_IMA_LSM_RULES to
reflect this.

Fixes: e79c26d0 ("apparmor: Add support for audit rule filtering")
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      1768215a
    • T
      ima: Rename internal filter rule functions · b8867eed
      由 Tyler Hicks 提交于 
      Rename IMA's internal filter rule functions from security_filter_rule_*()
to ima_filter_rule_*(). This avoids polluting the security_* namespace,
which is typically reserved for general security subsystem
infrastructure.
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Suggested-by: NCasey Schaufler <casey@schaufler-ca.com>
[zohar@linux.ibm.com: reword using the term "filter", not "audit"]
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      b8867eed
    • T
      ima: Support additional conditionals in the KEXEC_CMDLINE hook function · 4834177e
      由 Tyler Hicks 提交于 
      Take the properties of the kexec kernel's inode and the current task
ownership into consideration when matching a KEXEC_CMDLINE operation to
the rules in the IMA policy. This allows for some uniformity when
writing IMA policy rules for KEXEC_KERNEL_CHECK, KEXEC_INITRAMFS_CHECK,
and KEXEC_CMDLINE operations.

Prior to this patch, it was not possible to write a set of rules like
this:

 dont_measure func=KEXEC_KERNEL_CHECK obj_type=foo_t
 dont_measure func=KEXEC_INITRAMFS_CHECK obj_type=foo_t
 dont_measure func=KEXEC_CMDLINE obj_type=foo_t
 measure func=KEXEC_KERNEL_CHECK
 measure func=KEXEC_INITRAMFS_CHECK
 measure func=KEXEC_CMDLINE

The inode information associated with the kernel being loaded by a
kexec_kernel_load(2) syscall can now be included in the decision to
measure or not

Additonally, the uid, euid, and subj_* conditionals can also now be
used in KEXEC_CMDLINE rules. There was no technical reason as to why
those conditionals weren't being considered previously other than
ima_match_rules() didn't have a valid inode to use so it immediately
bailed out for KEXEC_CMDLINE operations rather than going through the
full list of conditional comparisons.
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: kexec@lists.infradead.org
Reviewed-by: NLakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      4834177e
    • T
      ima: Use the common function to detect LSM conditionals in a rule · 592b24cb
      由 Tyler Hicks 提交于 
      Make broader use of ima_rule_contains_lsm_cond() to check if a given
rule contains an LSM conditional. This is a code cleanup and has no
user-facing change.
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: NMimi Zohar <zohar@linux.ibm.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      592b24cb
    • T
      ima: Move comprehensive rule validation checks out of the token parser · 30031b0e
      由 Tyler Hicks 提交于 
      Use ima_validate_rule(), at the end of the token parsing stage, to
verify combinations of actions, hooks, and flags. This is useful to
increase readability by consolidating such checks into a single function
and also because rule conditionals can be specified in arbitrary order
making it difficult to do comprehensive rule validation until the entire
rule has been parsed.

This allows for the check that ties together the "keyrings" conditional
with the KEY_CHECK function hook to be moved into the final rule
validation.

The modsig check no longer needs to compiled conditionally because the
token parser will ensure that modsig support is enabled before accepting
"imasig|modsig" appraise type values. The final rule validation will
ensure that appraise_type and appraise_flag options are only present in
appraise rules.

Finally, this allows for the check that ties together the "pcr"
conditional with the measure action to be moved into the final rule
validation.
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      30031b0e
    • T
      ima: Use correct type for the args_p member of ima_rule_entry.lsm elements · aa0c0227
      由 Tyler Hicks 提交于 
      Make args_p be of the char pointer type rather than have it be a void
pointer that gets casted to char pointer when it is used. It is a simple
NUL-terminated string as returned by match_strdup().
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      aa0c0227
    • T
      ima: Shallow copy the args_p member of ima_rule_entry.lsm elements · 39e5993d
      由 Tyler Hicks 提交于 
      The args_p member is a simple string that is allocated by
ima_rule_init(). Shallow copy it like other non-LSM references in
ima_rule_entry structs.

There are no longer any necessary error path cleanups to do in
ima_lsm_copy_rule().
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      39e5993d
    • T
      ima: Fail rule parsing when appraise_flag=blacklist is unsupportable · 5f3e9265
      由 Tyler Hicks 提交于 
      Verifying that a file hash is not blacklisted is currently only
supported for files with appended signatures (modsig).  In the future,
this might change.

For now, the "appraise_flag" option is only appropriate for appraise
actions and its "blacklist" value is only appropriate when
CONFIG_IMA_APPRAISE_MODSIG is enabled and "appraise_flag=blacklist" is
only appropriate when "appraise_type=imasig|modsig" is also present.
Make this clear at policy load so that IMA policy authors don't assume
that other uses of "appraise_flag=blacklist" are supported.

Fixes: 273df864 ("ima: Check against blacklisted hashes for files with modsig")
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Reivewed-by: NNayna Jain <nayna@linux.ibm.com>
Tested-by: NNayna Jain <nayna@linux.ibm.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      5f3e9265
  5. 17 7月, 2020 8 次提交
    • T
      ima: Fail rule parsing when the KEY_CHECK hook is combined with an invalid cond · eb624fe2
      由 Tyler Hicks 提交于 
      The KEY_CHECK function only supports the uid, pcr, and keyrings
conditionals. Make this clear at policy load so that IMA policy authors
don't assume that other conditionals are supported.

Fixes: 5808611c ("IMA: Add KEY_CHECK func to measure keys")
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: NLakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      eb624fe2
    • T
      ima: Fail rule parsing when the KEXEC_CMDLINE hook is combined with an invalid cond · db2045f5
      由 Tyler Hicks 提交于 
      The KEXEC_CMDLINE hook function only supports the pcr conditional. Make
this clear at policy load so that IMA policy authors don't assume that
other conditionals are supported.

Since KEXEC_CMDLINE's inception, ima_match_rules() has always returned
true on any loaded KEXEC_CMDLINE rule without any consideration for
other conditionals present in the rule. Make it clear that pcr is the
only supported KEXEC_CMDLINE conditional by returning an error during
policy load.

An example of why this is a problem can be explained with the following
rule:

 dont_measure func=KEXEC_CMDLINE obj_type=foo_t

An IMA policy author would have assumed that rule is valid because the
parser accepted it but the result was that measurements for all
KEXEC_CMDLINE operations would be disabled.

Fixes: b0935123 ("IMA: Define a new hook to measure the kexec boot command line arguments")
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: NMimi Zohar <zohar@linux.ibm.com>
Reviewed-by: NLakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      db2045f5
    • T
      ima: Fail rule parsing when buffer hook functions have an invalid action · 71218343
      由 Tyler Hicks 提交于 
      Buffer based hook functions, such as KEXEC_CMDLINE and KEY_CHECK, can
only measure. The process_buffer_measurement() function quietly ignores
all actions except measure so make this behavior clear at the time of
policy load.

The parsing of the keyrings conditional had a check to ensure that it
was only specified with measure actions but the check should be on the
hook function and not the keyrings conditional since
"appraise func=KEY_CHECK" is not a valid rule.

Fixes: b0935123 ("IMA: Define a new hook to measure the kexec boot command line arguments")
Fixes: 5808611c ("IMA: Add KEY_CHECK func to measure keys")
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      71218343
    • T
      ima: Free the entire rule if it fails to parse · 2bdd737c
      由 Tyler Hicks 提交于 
      Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry
members, such as .fsname and .keyrings, when an error is encountered
during rule parsing.

Set the args_p pointer to NULL after freeing it in the error path of
ima_lsm_rule_init() so that it isn't freed twice.

This fixes a memory leak seen when loading an rule that contains an
additional piece of allocated memory, such as an fsname, followed by an
invalid conditional:

 # echo "measure fsname=tmpfs bad=cond" > /sys/kernel/security/ima/policy
 -bash: echo: write error: Invalid argument
 # echo scan > /sys/kernel/debug/kmemleak
 # cat /sys/kernel/debug/kmemleak
 unreferenced object 0xffff98e7e4ece6c0 (size 8):
   comm "bash", pid 672, jiffies 4294791843 (age 21.855s)
   hex dump (first 8 bytes):
     74 6d 70 66 73 00 6b a5                          tmpfs.k.
   backtrace:
     [<00000000abab7413>] kstrdup+0x2e/0x60
     [<00000000f11ede32>] ima_parse_add_rule+0x7d4/0x1020
     [<00000000f883dd7a>] ima_write_policy+0xab/0x1d0
     [<00000000b17cf753>] vfs_write+0xde/0x1d0
     [<00000000b8ddfdea>] ksys_write+0x68/0xe0
     [<00000000b8e21e87>] do_syscall_64+0x56/0xa0
     [<0000000089ea7b98>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: f1b08bbc ("ima: define a new policy condition based on the filesystem name")
Fixes: 2b60c0ec ("IMA: Read keyrings= option from the IMA policy")
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      2bdd737c
    • T
      ima: Free the entire rule when deleting a list of rules · 465aee77
      由 Tyler Hicks 提交于 
      Create a function, ima_free_rule(), to free all memory associated with
an ima_rule_entry. Use the new function to fix memory leaks of allocated
ima_rule_entry members, such as .fsname and .keyrings, when deleting a
list of rules.

Make the existing ima_lsm_free_rule() function specific to the LSM
audit rule array of an ima_rule_entry and require that callers make an
additional call to kfree to free the ima_rule_entry itself.

This fixes a memory leak seen when loading by a valid rule that contains
an additional piece of allocated memory, such as an fsname, followed by
an invalid rule that triggers a policy load failure:

 # echo -e "dont_measure fsname=securityfs\nbad syntax" > \
    /sys/kernel/security/ima/policy
 -bash: echo: write error: Invalid argument
 # echo scan > /sys/kernel/debug/kmemleak
 # cat /sys/kernel/debug/kmemleak
 unreferenced object 0xffff9bab67ca12c0 (size 16):
   comm "bash", pid 684, jiffies 4295212803 (age 252.344s)
   hex dump (first 16 bytes):
     73 65 63 75 72 69 74 79 66 73 00 6b 6b 6b 6b a5  securityfs.kkkk.
   backtrace:
     [<00000000adc80b1b>] kstrdup+0x2e/0x60
     [<00000000d504cb0d>] ima_parse_add_rule+0x7d4/0x1020
     [<00000000444825ac>] ima_write_policy+0xab/0x1d0
     [<000000002b7f0d6c>] vfs_write+0xde/0x1d0
     [<0000000096feedcf>] ksys_write+0x68/0xe0
     [<0000000052b544a2>] do_syscall_64+0x56/0xa0
     [<000000007ead1ba7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: f1b08bbc ("ima: define a new policy condition based on the filesystem name")
Fixes: 2b60c0ec ("IMA: Read keyrings= option from the IMA policy")
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      465aee77
    • T
      ima: Have the LSM free its audit rule · 9ff8a616
      由 Tyler Hicks 提交于 
      Ask the LSM to free its audit rule rather than directly calling kfree().
Both AppArmor and SELinux do additional work in their audit_rule_free()
hooks. Fix memory leaks by allowing the LSMs to perform necessary work.

Fixes: b1694245 ("ima: use the lsm policy update notifier")
Signed-off-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Cc: Janne Karhunen <janne.karhunen@gmail.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: NMimi Zohar <zohar@linux.ibm.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      9ff8a616
    • L
      IMA: Add audit log for failure conditions · 34e980bb
      由 Lakshmi Ramasubramanian 提交于 
      process_buffer_measurement() and ima_alloc_key_entry() functions need to
log an audit message for auditing integrity measurement failures.

Add audit message in these two functions. Remove "pr_devel" log message
in process_buffer_measurement().

Sample audit messages:

[    6.303048] audit: type=1804 audit(1592506281.627:2): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=kernel op=measuring_key cause=ENOMEM comm="swapper/0" name=".builtin_trusted_keys" res=0 errno=-12

[    8.019432] audit: type=1804 audit(1592506283.344:10): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 op=measuring_kexec_cmdline cause=hashing_error comm="systemd" name="kexec-cmdline" res=0 errno=-22
Signed-off-by: NLakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: NMimi Zohar <zohar@linux.ibm.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      34e980bb
    • L
      integrity: Add errno field in audit message · 2f845882
      由 Lakshmi Ramasubramanian 提交于 
      Error code is not included in the audit messages logged by
the integrity subsystem.

Define a new function integrity_audit_message() that takes error code
in the "errno" parameter. Add "errno" field in the audit messages logged
by the integrity subsystem and set the value passed in the "errno"
parameter.

[    6.303048] audit: type=1804 audit(1592506281.627:2): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=kernel op=measuring_key cause=ENOMEM comm="swapper/0" name=".builtin_trusted_keys" res=0 errno=-12

[    7.987647] audit: type=1802 audit(1592506283.312:9): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 op=policy_update cause=completed comm="systemd" res=1 errno=0

[    8.019432] audit: type=1804 audit(1592506283.344:10): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 op=measuring_kexec_cmdline cause=hashing_error comm="systemd" name="kexec-cmdline" res=0 errno=-22
Signed-off-by: NLakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: NSteve Grubb <sgrubb@redhat.com>
Suggested-by: NMimi Zohar <zohar@linux.ibm.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      2f845882
  7. 08 7月, 2020 1 次提交
  9. 25 6月, 2020 1 次提交
  11. 16 6月, 2020 1 次提交
  13. 12 6月, 2020 1 次提交
  15. 08 6月, 2020 1 次提交
  17. 05 6月, 2020 1 次提交
    • R
      ima: Directly free *entry in ima_alloc_init_template() if digests is NULL · 42413b49
      由 Roberto Sassu 提交于 
      To support multiple template digests, the static array entry->digest has
been replaced with a dynamically allocated array in commit aa724fe1
("ima: Switch to dynamically allocated buffer for template digests"). The
array is allocated in ima_alloc_init_template() and if the returned pointer
is NULL, ima_free_template_entry() is called.

However, (*entry)->template_desc is not yet initialized while it is used by
ima_free_template_entry(). This patch fixes the issue by directly freeing
*entry without calling ima_free_template_entry().

Fixes: aa724fe1 ("ima: Switch to dynamically allocated buffer for template digests")
Reported-by: syzbot+223310b454ba6b75974e@syzkaller.appspotmail.com
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      42413b49
  19. 04 6月, 2020 2 次提交
    • R
      ima: Call ima_calc_boot_aggregate() in ima_eventdigest_init() · 6cc7c266
      由 Roberto Sassu 提交于 
      If the template field 'd' is chosen and the digest to be added to the
measurement entry was not calculated with SHA1 or MD5, it is
recalculated with SHA1, by using the passed file descriptor. However, this
cannot be done for boot_aggregate, because there is no file descriptor.

This patch adds a call to ima_calc_boot_aggregate() in
ima_eventdigest_init(), so that the digest can be recalculated also for the
boot_aggregate entry.

Cc: stable@vger.kernel.org # 3.13.x
Fixes: 3ce1217d ("ima: define template fields library and new helpers")
Reported-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      6cc7c266
    • R
      ima: Directly assign the ima_default_policy pointer to ima_rules · 067a436b
      由 Roberto Sassu 提交于 
      This patch prevents the following oops:

[   10.771813] BUG: kernel NULL pointer dereference, address: 0000000000000
[...]
[   10.779790] RIP: 0010:ima_match_policy+0xf7/0xb80
[...]
[   10.798576] Call Trace:
[   10.798993]  ? ima_lsm_policy_change+0x2b0/0x2b0
[   10.799753]  ? inode_init_owner+0x1a0/0x1a0
[   10.800484]  ? _raw_spin_lock+0x7a/0xd0
[   10.801592]  ima_must_appraise.part.0+0xb6/0xf0
[   10.802313]  ? ima_fix_xattr.isra.0+0xd0/0xd0
[   10.803167]  ima_must_appraise+0x4f/0x70
[   10.804004]  ima_post_path_mknod+0x2e/0x80
[   10.804800]  do_mknodat+0x396/0x3c0

It occurs when there is a failure during IMA initialization, and
ima_init_policy() is not called. IMA hooks still call ima_match_policy()
but ima_rules is NULL. This patch prevents the crash by directly assigning
the ima_default_policy pointer to ima_rules when ima_rules is defined. This
wouldn't alter the existing behavior, as ima_rules is always set at the end
of ima_init_policy().

Cc: stable@vger.kernel.org # 3.7.x
Fixes: 07f6a794 ("ima: add appraise action keywords and default rules")
Reported-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NRoberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
      067a436b
  21. 23 5月, 2020 1 次提交
  23. 15 5月, 2020 1 次提交
  25. 08 5月, 2020 8 次提交
  27. 20 4月, 2020 4 次提交