Smack: adds smackfs/ptrace interface
This allows to limit ptrace beyond the regular smack access rules.
It adds a smackfs/ptrace interface that allows smack to be configured
to require equal smack labels for PTRACE_MODE_ATTACH access.
See the changes in Documentation/security/Smack.txt below for details.
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
diff --git a/Documentation/security/Smack.txt b/Documentation/security/Smack.txt
index 7a2d30c..5597917 100644
--- a/Documentation/security/Smack.txt
+++ b/Documentation/security/Smack.txt
@@ -204,6 +204,16 @@
these capabilities are effective at for processes with any
label. The value is set by writing the desired label to the
file or cleared by writing "-" to the file.
+ptrace
+ This is used to define the current ptrace policy
+ 0 - default: this is the policy that relies on smack access rules.
+ For the PTRACE_READ a subject needs to have a read access on
+ object. For the PTRACE_ATTACH a read-write access is required.
+ 1 - exact: this is the policy that limits PTRACE_ATTACH. Attach is
+ only allowed when subject's and object's labels are equal.
+ PTRACE_READ is not affected. Can be overriden with CAP_SYS_PTRACE.
+ 2 - draconian: this policy behaves like the 'exact' above with an
+ exception that it can't be overriden with CAP_SYS_PTRACE.
revoke-subject
Writing a Smack label here sets the access to '-' for all access
rules with that subject label.