WSL2-Linux-Kernel/security
Mimi Zohar 867c202654 ima: fix add LSM rule bug
If security_filter_rule_init() doesn't return a rule, then not everything
is as fine as the return code implies.

This bug only occurs when the LSM (eg. SELinux) is disabled at runtime.

Adding an empty LSM rule causes ima_match_rules() to always succeed,
ignoring any remaining rules.

 default IMA TCB policy:
  # PROC_SUPER_MAGIC
  dont_measure fsmagic=0x9fa0
  # SYSFS_MAGIC
  dont_measure fsmagic=0x62656572
  # DEBUGFS_MAGIC
  dont_measure fsmagic=0x64626720
  # TMPFS_MAGIC
  dont_measure fsmagic=0x01021994
  # SECURITYFS_MAGIC
  dont_measure fsmagic=0x73636673

  < LSM specific rule >
  dont_measure obj_type=var_log_t

  measure func=BPRM_CHECK
  measure func=FILE_MMAP mask=MAY_EXEC
  measure func=FILE_CHECK mask=MAY_READ uid=0

Thus without the patch, with the boot parameters 'tcb selinux=0', adding
the above 'dont_measure obj_type=var_log_t' rule to the default IMA TCB
measurement policy, would result in nothing being measured.  The patch
prevents the default TCB policy from being replaced.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Cc: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: David Safford <safford@watson.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-03 16:36:33 -08:00
..
apparmor APPARMOR: Fix memory leak of apparmor_init() 2010-11-11 07:36:22 +11:00
integrity/ima ima: fix add LSM rule bug 2011-01-03 16:36:33 -08:00
keys KEYS: Don't call up_write() if __key_link_begin() returns an error 2010-12-23 15:31:48 -08:00
selinux capabilities/syslog: open code cap_syslog logic to fix build failure 2010-11-15 15:40:01 -08:00
smack capabilities/syslog: open code cap_syslog logic to fix build failure 2010-11-15 15:40:01 -08:00
tomoyo fs: take dcache_lock inside __d_path 2010-10-25 21:26:12 -04:00
Kconfig Restrict unprivileged access to kernel syslog 2010-11-12 07:55:32 -08:00
Makefile AppArmor: Enable configuring and building of the AppArmor security module 2010-08-02 15:38:34 +10:00
capability.c capabilities/syslog: open code cap_syslog logic to fix build failure 2010-11-15 15:40:01 -08:00
commoncap.c capabilities/syslog: open code cap_syslog logic to fix build failure 2010-11-15 15:40:01 -08:00
device_cgroup.c Merge branch 'master' into next 2010-05-06 10:56:07 +10:00
inode.c convert get_sb_single() users 2010-10-29 04:16:28 -04:00
lsm_audit.c Merge branch 'master' into next 2010-05-06 10:56:07 +10:00
min_addr.c mmap_min_addr check CAP_SYS_RAWIO only for write 2010-04-23 08:56:31 +10:00
security.c capabilities/syslog: open code cap_syslog logic to fix build failure 2010-11-15 15:40:01 -08:00