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| author | Lucian Adrian Grijincu <lucian.grijincu@gmail.com> | 2011-02-01 19:42:22 +0300 |
|---|---|---|
| committer | Eric Paris <eparis@redhat.com> | 2011-02-01 19:53:54 +0300 |
| commit | 8e6c96935fcc1ed3dbebc96fddfef3f2f2395afc (patch) | |
| tree | c26297c8ca479972010cadf2058aacd63ce1744f /fs/proc | |
| parent | 652bb9b0d6ce007f37c098947b2cc0c45efa3f66 (diff) | |
| download | linux-8e6c96935fcc1ed3dbebc96fddfef3f2f2395afc.tar.xz | |
security/selinux: fix /proc/sys/ labeling
This fixes an old (2007) selinux regression: filesystem labeling for
/proc/sys returned
-r--r--r-- unknown /proc/sys/fs/file-nr
instead of
-r--r--r-- system_u:object_r:sysctl_fs_t:s0 /proc/sys/fs/file-nr
Events that lead to breaking of /proc/sys/ selinux labeling:
1) sysctl was reimplemented to route all calls through /proc/sys/
commit 77b14db502cb85a031fe8fde6c85d52f3e0acb63
[PATCH] sysctl: reimplement the sysctl proc support
2) proc_dir_entry was removed from ctl_table:
commit 3fbfa98112fc3962c416452a0baf2214381030e6
[PATCH] sysctl: remove the proc_dir_entry member for the sysctl tables
3) selinux still walked the proc_dir_entry tree to apply
labeling. Because ctl_tables don't have a proc_dir_entry, we did
not label /proc/sys/ inodes any more. To achieve this the /proc/sys/
inodes were marked private and private inodes were ignored by
selinux.
commit bbaca6c2e7ef0f663bc31be4dad7cf530f6c4962
[PATCH] selinux: enhance selinux to always ignore private inodes
commit 86a71dbd3e81e8870d0f0e56b87875f57e58222b
[PATCH] sysctl: hide the sysctl proc inodes from selinux
Access control checks have been done by means of a special sysctl hook
that was called for read/write accesses to any /proc/sys/ entry.
We don't have to do this because, instead of walking the
proc_dir_entry tree we can walk the dentry tree (as done in this
patch). With this patch:
* we don't mark /proc/sys/ inodes as private
* we don't need the sysclt security hook
* we walk the dentry tree to find the path to the inode.
We have to strip the PID in /proc/PID/ entries that have a
proc_dir_entry because selinux does not know how to label paths like
'/1/net/rpc/nfsd.fh' (and defaults to 'proc_t' labeling). Selinux does
know of '/net/rpc/nfsd.fh' (and applies the 'sysctl_rpc_t' label).
PID stripping from the path was done implicitly in the previous code
because the proc_dir_entry tree had the root in '/net' in the example
from above. The dentry tree has the root in '/1'.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/proc_sysctl.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 09a1f92a34ef..fb707e018a81 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -32,7 +32,6 @@ static struct inode *proc_sys_make_inode(struct super_block *sb, ei->sysctl_entry = table; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; - inode->i_flags |= S_PRIVATE; /* tell selinux to ignore this inode */ inode->i_mode = table->mode; if (!table->child) { inode->i_mode |= S_IFREG; |