Skip to content

L
linux
Switch branch/tag
  1. 14 Jul, 2008 6 commits
    • Stephen Smalley's avatar
      Security: split proc ptrace checking into read vs. attach · 006ebb40
      Stephen Smalley authored 
      Enable security modules to distinguish reading of process state via
proc from full ptrace access by renaming ptrace_may_attach to
ptrace_may_access and adding a mode argument indicating whether only
read access or full attach access is requested.  This allows security
modules to permit access to reading process state without granting
full ptrace access.  The base DAC/capability checking remains unchanged.

Read access to /proc/pid/mem continues to apply a full ptrace attach
check since check_mem_permission() already requires the current task
to already be ptracing the target.  The other ptrace checks within
proc for elements like environ, maps, and fds are changed to pass the
read mode instead of attach.

In the SELinux case, we model such reading of process state as a
reading of a proc file labeled with the target process' label.  This
enables SELinux policy to permit such reading of process state without
permitting control or manipulation of the target process, as there are
a number of cases where programs probe for such information via proc
but do not need to be able to control the target (e.g. procps,
lsof, PolicyKit, ConsoleKit).  At present we have to choose between
allowing full ptrace in policy (more permissive than required/desired)
or breaking functionality (or in some cases just silencing the denials
via dontaudit rules but this can hide genuine attacks).

This version of the patch incorporates comments from Casey Schaufler
(change/replace existing ptrace_may_attach interface, pass access
mode), and Chris Wright (provide greater consistency in the checking).

Note that like their predecessors __ptrace_may_attach and
ptrace_may_attach, the __ptrace_may_access and ptrace_may_access
interfaces use different return value conventions from each other (0
or -errno vs. 1 or 0).  I retained this difference to avoid any
changes to the caller logic but made the difference clearer by
changing the latter interface to return a bool rather than an int and
by adding a comment about it to ptrace.h for any future callers.
Signed-off-by: default avatarStephen Smalley <sds@tycho.nsa.gov>
Acked-by: default avatarChris Wright <chrisw@sous-sol.org>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      006ebb40
    • James Morris's avatar
      SELinux: remove inherit field from inode_security_struct · feb2a5b8
      James Morris authored 
      Remove inherit field from inode_security_struct, per Stephen Smalley:
"Let's just drop inherit altogether - dead field."
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      feb2a5b8
    • Richard Kennedy's avatar
      SELinux: reorder inode_security_struct to increase objs/slab on 64bit · fdeb0518
      Richard Kennedy authored 
      reorder inode_security_struct to remove padding on 64 bit builds

size reduced from 72 to 64 bytes increasing objects per slab to 64.
Signed-off-by: default avatarRichard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      fdeb0518
    • Eric Paris's avatar
      SELinux: keep the code clean formating and syntax · f5269710
      Eric Paris authored 
      Formatting and syntax changes

whitespace, tabs to spaces, trailing space
put open { on same line as struct def
remove unneeded {} after if statements
change printk("Lu") to printk("llu")
convert asm/uaccess.h to linux/uaacess.h includes
remove unnecessary asm/bug.h includes
convert all users of simple_strtol to strict_strtol
Signed-off-by: default avatarEric Paris <eparis@redhat.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      f5269710
    • Stephen Smalley's avatar
      SELinux: fix sleeping allocation in security_context_to_sid · 9a59daa0
      Stephen Smalley authored 
      Fix a sleeping function called from invalid context bug by moving allocation
to the callers prior to taking the policy rdlock.
Signed-off-by: default avatarStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      9a59daa0
    • Stephen Smalley's avatar
      selinux: support deferred mapping of contexts · 12b29f34
      Stephen Smalley authored 
      Introduce SELinux support for deferred mapping of security contexts in
the SID table upon policy reload, and use this support for inode
security contexts when the context is not yet valid under the current
policy.  Only processes with CAP_MAC_ADMIN + mac_admin permission in
policy can set undefined security contexts on inodes.  Inodes with
such undefined contexts are treated as having the unlabeled context
until the context becomes valid upon a policy reload that defines the
context.  Context invalidation upon policy reload also uses this
support to save the context information in the SID table and later
recover it upon a subsequent policy reload that defines the context
again.

This support is to enable package managers and similar programs to set
down file contexts unknown to the system policy at the time the file
is created in order to better support placing loadable policy modules
in packages and to support build systems that need to create images of
different distro releases with different policies w/o requiring all of
the contexts to be defined or legal in the build host policy.

With this patch applied, the following sequence is possible, although
in practice it is recommended that this permission only be allowed to
specific program domains such as the package manager.

# rmdir baz
# rm bar
# touch bar
# chcon -t foo_exec_t bar # foo_exec_t is not yet defined
chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument
# mkdir -Z system_u:object_r:foo_exec_t baz
mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument
# cat setundefined.te
policy_module(setundefined, 1.0)
require {
	type unconfined_t;
	type unlabeled_t;
}
files_type(unlabeled_t)
allow unconfined_t self:capability2 mac_admin;
# make -f /usr/share/selinux/devel/Makefile setundefined.pp
# semodule -i setundefined.pp
# chcon -t foo_exec_t bar # foo_exec_t is not yet defined
# mkdir -Z system_u:object_r:foo_exec_t baz
# ls -Zd bar baz
-rw-r--r--  root root system_u:object_r:unlabeled_t    bar
drwxr-xr-x  root root system_u:object_r:unlabeled_t    baz
# cat foo.te
policy_module(foo, 1.0)
type foo_exec_t;
files_type(foo_exec_t)
# make -f /usr/share/selinux/devel/Makefile foo.pp
# semodule -i foo.pp # defines foo_exec_t
# ls -Zd bar baz
-rw-r--r--  root root user_u:object_r:foo_exec_t       bar
drwxr-xr-x  root root system_u:object_r:foo_exec_t    baz
# semodule -r foo
# ls -Zd bar baz
-rw-r--r--  root root system_u:object_r:unlabeled_t    bar
drwxr-xr-x  root root system_u:object_r:unlabeled_t    baz
# semodule -i foo.pp
# ls -Zd bar baz
-rw-r--r--  root root user_u:object_r:foo_exec_t       bar
drwxr-xr-x  root root system_u:object_r:foo_exec_t    baz
# semodule -r setundefined foo
# chcon -t foo_exec_t bar # no longer defined and not allowed
chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument
# rmdir baz
# mkdir -Z system_u:object_r:foo_exec_t baz
mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument
Signed-off-by: default avatarStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      12b29f34
  3. 13 Jul, 2008 6 commits
  5. 12 Jul, 2008 17 commits
  7. 11 Jul, 2008 11 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7