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| author | Zbigniew Jasinski <z.jasinski@samsung.com> | 2015-10-19 18:23:53 +0200 |
|---|---|---|
| committer | Casey Schaufler <casey@schaufler-ca.com> | 2015-10-19 21:06:47 +0200 |
| commit | 38416e53936ecf896948fdeffc36b76979117952 (patch) | |
| tree | b0ac68de5a0b4a7953ab38e7dcc6fa1d8a83d10a /Documentation/security | |
| parent | Smack: pipefs fix in smack_d_instantiate (diff) | |
| download | linux-38416e53936ecf896948fdeffc36b76979117952.tar.xz linux-38416e53936ecf896948fdeffc36b76979117952.zip | |
Smack: limited capability for changing process label
This feature introduces new kernel interface:
- <smack_fs>/relabel-self - for setting transition labels list
This list is used to control smack label transition mechanism.
List is set by, and per process. Process can transit to new label only if
label is on the list. Only process with CAP_MAC_ADMIN capability can add
labels to this list. With this list, process can change it's label without
CAP_MAC_ADMIN but only once. After label changing, list is unset.
Changes in v2:
* use list_for_each_entry instead of _rcu during label write
* added missing description in security/Smack.txt
Changes in v3:
* squashed into one commit
Changes in v4:
* switch from global list to per-task list
* since the per-task list is accessed only by the task itself
there is no need to use synchronization mechanisms on it
Changes in v5:
* change smackfs interface of relabel-self to the one used for onlycap
multiple labels are accepted, separated by space, which
replace the previous list upon write
Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Diffstat (limited to 'Documentation/security')
| -rw-r--r-- | Documentation/security/Smack.txt | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/security/Smack.txt b/Documentation/security/Smack.txt index 5e6d07fbed07..945cc633d883 100644 --- a/Documentation/security/Smack.txt +++ b/Documentation/security/Smack.txt @@ -255,6 +255,16 @@ unconfined the access permitted if it wouldn't be otherwise. Note that this is dangerous and can ruin the proper labeling of your system. It should never be used in production. +relabel-self + This interface contains a list of labels to which the process can + transition to, by writing to /proc/self/attr/current. + Normally a process can change its own label to any legal value, but only + if it has CAP_MAC_ADMIN. This interface allows a process without + CAP_MAC_ADMIN to relabel itself to one of labels from predefined list. + A process without CAP_MAC_ADMIN can change its label only once. When it + does, this list will be cleared. + The values are set by writing the desired labels, separated + by spaces, to the file or cleared by writing "-" to the file. If you are using the smackload utility you can add access rules in /etc/smack/accesses. They take the form: |