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path: root/fs/proc/namespaces.c
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* proc: Pass file mode to proc_pid_make_inodeAndreas Gruenbacher2016-11-141-2/+1
| | | | | | | | | | | Pass the file mode of the proc inode to be created to proc_pid_make_inode. In proc_pid_make_inode, initialize inode->i_mode before calling security_task_to_inode. This allows selinux to set isec->sclass right away without introducing "half-initialized" inode security structs. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* switch all procfs directories ->iterate_shared()Al Viro2016-05-021-1/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* cgroup: introduce cgroup namespacesAditya Kali2016-02-161-0/+3
| | | | | | | | | | | | | | | | | | | Introduce the ability to create new cgroup namespace. The newly created cgroup namespace remembers the cgroup of the process at the point of creation of the cgroup namespace (referred as cgroupns-root). The main purpose of cgroup namespace is to virtualize the contents of /proc/self/cgroup file. Processes inside a cgroup namespace are only able to see paths relative to their namespace root (unless they are moved outside of their cgroupns-root, at which point they will see a relative path from their cgroupns-root). For a correctly setup container this enables container-tools (like libcontainer, lxc, lmctfy, etc.) to create completely virtualized containers without leaking system level cgroup hierarchy to the task. This patch only implements the 'unshare' part of the cgroupns. Signed-off-by: Aditya Kali <adityakali@google.com> Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* ptrace: use fsuid, fsgid, effective creds for fs access checksJann Horn2016-01-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By checking the effective credentials instead of the real UID / permitted capabilities, ensure that the calling process actually intended to use its credentials. To ensure that all ptrace checks use the correct caller credentials (e.g. in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS flag), use two new flags and require one of them to be set. The problem was that when a privileged task had temporarily dropped its privileges, e.g. by calling setreuid(0, user_uid), with the intent to perform following syscalls with the credentials of a user, it still passed ptrace access checks that the user would not be able to pass. While an attacker should not be able to convince the privileged task to perform a ptrace() syscall, this is a problem because the ptrace access check is reused for things in procfs. In particular, the following somewhat interesting procfs entries only rely on ptrace access checks: /proc/$pid/stat - uses the check for determining whether pointers should be visible, useful for bypassing ASLR /proc/$pid/maps - also useful for bypassing ASLR /proc/$pid/cwd - useful for gaining access to restricted directories that contain files with lax permissions, e.g. in this scenario: lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar drwx------ root root /root drwxr-xr-x root root /root/foobar -rw-r--r-- root root /root/foobar/secret Therefore, on a system where a root-owned mode 6755 binary changes its effective credentials as described and then dumps a user-specified file, this could be used by an attacker to reveal the memory layout of root's processes or reveal the contents of files he is not allowed to access (through /proc/$pid/cwd). [akpm@linux-foundation.org: fix warning] Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* switch ->get_link() to delayed_call, kill ->put_link()Al Viro2015-12-301-1/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* replace ->follow_link() with new method that could stay in RCU modeAl Viro2015-12-081-3/+6
| | | | | | | | | | | | | | | | | | new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't pass nameidata to ->follow_link()Al Viro2015-05-101-2/+2
| | | | | | | its only use is getting passed to nd_jump_link(), which can obtain it from current->nameidata Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new ->follow_link() and ->put_link() calling conventionsAl Viro2015-05-101-1/+1
| | | | | | | | | | | | | | | | | | | a) instead of storing the symlink body (via nd_set_link()) and returning an opaque pointer later passed to ->put_link(), ->follow_link() _stores_ that opaque pointer (into void * passed by address by caller) and returns the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic symlinks) and pointer to symlink body for normal symlinks. Stored pointer is ignored in all cases except the last one. Storing NULL for opaque pointer (or not storing it at all) means no call of ->put_link(). b) the body used to be passed to ->put_link() implicitly (via nameidata). Now only the opaque pointer is. In the cases when we used the symlink body to free stuff, ->follow_link() now should store it as opaque pointer in addition to returning it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells2015-04-151-2/+2
| | | | | | | that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* kill proc_ns completelyAl Viro2014-12-101-3/+3
| | | | | | procfs inodes need only the ns_ops part; nsfs inodes don't need it at all Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* take the targets of /proc/*/ns/* symlinks to separate fsAl Viro2014-12-101-139/+13
| | | | | | | | | | | | | | | | | | | | | | | New pseudo-filesystem: nsfs. Targets of /proc/*/ns/* live there now. It's not mountable (not even registered, so it's not in /proc/filesystems, etc.). Files on it *are* bindable - we explicitly permit that in do_loopback(). This stuff lives in fs/nsfs.c now; proc_ns_fget() moved there as well. get_proc_ns() is a macro now (it's simply returning ->i_private; would have been an inline, if not for header ordering headache). proc_ns_inode() is an ex-parrot. The interface used in procfs is ns_get_path(path, task, ops) and ns_get_name(buf, size, task, ops). Dentries and inodes are never hashed; a non-counting reference to dentry is stashed in ns_common (removed by ->d_prune()) and reused by ns_get_path() if present. See ns_get_path()/ns_prune_dentry/nsfs_evict() for details of that mechanism. As the result, proc_ns_follow_link() has stopped poking in nd->path.mnt; it does nd_jump_link() on a consistent <vfsmount,dentry> pair it gets from ns_get_path(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* bury struct proc_ns in fs/procAl Viro2014-12-041-3/+4
| | | | | | | | | | a) make get_proc_ns() return a pointer to struct ns_common b) mirror ns_ops in dentry->d_fsdata of ns dentries, so that is_mnt_ns_file() could get away with fewer dereferences. That way struct proc_ns becomes invisible outside of fs/proc/*.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* make proc_ns_operations work with struct ns_common * instead of void *Al Viro2014-12-041-4/+4
| | | | | | | We can do that now. And kill ->inum(), while we are at it - all instances are identical. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: readlink_copy()Al Viro2014-04-011-10/+4
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* consolidate simple ->d_delete() instancesAl Viro2013-11-151-7/+1
| | | | | | | | Rename simple_delete_dentry() to always_delete_dentry() and export it. Export simple_dentry_operations, while we are at it, and get rid of their duplicates Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* proc_fill_cache(): just make instantiate_t return intAl Viro2013-06-291-7/+6
| | | | | | all instances always return ERR_PTR(-E...) or NULL, anyway Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [readdir] convert procfsAl Viro2013-06-291-56/+18
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* proc: Split the namespace stuff out into linux/proc_ns.hDavid Howells2013-05-011-6/+11
| | | | | | | | | | Split the proc namespace stuff out into linux/proc_ns.h. Signed-off-by: David Howells <dhowells@redhat.com> cc: netdev@vger.kernel.org cc: Serge E. Hallyn <serge.hallyn@ubuntu.com> cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* proc: Use nd_jump_link in proc_ns_follow_linkEric W. Biederman2013-03-091-6/+6
| | | | | | | | | | | | | | | | Update proc_ns_follow_link to use nd_jump_link instead of just manually updating nd.path.dentry. This fixes the BUG_ON(nd->inode != parent->d_inode) reported by Dave Jones and reproduced trivially with mkdir /proc/self/ns/uts/a. Sigh it looks like the VFS change to require use of nd_jump_link happend while proc_ns_follow_link was baking and since the common case of proc_ns_follow_link continued to work without problems the need for making this change was overlooked. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* proc: Usable inode numbers for the namespace file descriptors.Eric W. Biederman2012-11-201-10/+14
| | | | | | | | | | | | | | | | | | | | | | | | | Assign a unique proc inode to each namespace, and use that inode number to ensure we only allocate at most one proc inode for every namespace in proc. A single proc inode per namespace allows userspace to test to see if two processes are in the same namespace. This has been a long requested feature and only blocked because a naive implementation would put the id in a global space and would ultimately require having a namespace for the names of namespaces, making migration and certain virtualization tricks impossible. We still don't have per superblock inode numbers for proc, which appears necessary for application unaware checkpoint/restart and migrations (if the application is using namespace file descriptors) but that is now allowd by the design if it becomes important. I have preallocated the ipc and uts initial proc inode numbers so their structures can be statically initialized. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* proc: Fix the namespace inode permission checks.Eric W. Biederman2012-11-201-21/+148
| | | | | | | | | | | | | Change the proc namespace files into symlinks so that we won't cache the dentries for the namespace files which can bypass the ptrace_may_access checks. To support the symlinks create an additional namespace inode with it's own set of operations distinct from the proc pid inode and dentry methods as those no longer make sense. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* userns: Implent proc namespace operationsEric W. Biederman2012-11-201-0/+4
| | | | | | | | | | | | This allows entering a user namespace, and the ability to store a reference to a user namespace with a bind mount. Addition of missing userns_ns_put in userns_install from Gao feng <gaofeng@cn.fujitsu.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* vfs: Add setns support for the mount namespaceEric W. Biederman2012-11-191-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | setns support for the mount namespace is a little tricky as an arbitrary decision must be made about what to set fs->root and fs->pwd to, as there is no expectation of a relationship between the two mount namespaces. Therefore I arbitrarily find the root mount point, and follow every mount on top of it to find the top of the mount stack. Then I set fs->root and fs->pwd to that location. The topmost root of the mount stack seems like a reasonable place to be. Bind mount support for the mount namespace inodes has the possibility of creating circular dependencies between mount namespaces. Circular dependencies can result in loops that prevent mount namespaces from every being freed. I avoid creating those circular dependencies by adding a sequence number to the mount namespace and require all bind mounts be of a younger mount namespace into an older mount namespace. Add a helper function proc_ns_inode so it is possible to detect when we are attempting to bind mound a namespace inode. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* pidns: Add setns supportEric W. Biederman2012-11-191-0/+3
| | | | | | | | | | | - Pid namespaces are designed to be inescapable so verify that the passed in pid namespace is a child of the currently active pid namespace or the currently active pid namespace itself. Allowing the currently active pid namespace is important so the effects of an earlier setns can be cancelled. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* stop passing nameidata to ->lookup()Al Viro2012-07-141-1/+1
| | | | | | | | | Just the flags; only NFS cares even about that, but there are legitimate uses for such argument. And getting rid of that completely would require splitting ->lookup() into a couple of methods (at least), so let's leave that alone for now... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* stop passing nameidata * to ->d_revalidate()Al Viro2012-07-141-1/+1
| | | | | | Just the lookup flags. Die, bastard, die... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs/proc/namespaces.c: prevent crash when ns_entries[] is emptyAndrew Morton2012-03-281-3/+3
| | | | | | | | | | | | If CONFIG_NET_NS, CONFIG_UTS_NS and CONFIG_IPC_NS are disabled, ns_entries[] becomes empty and things like ns_entries[ARRAY_SIZE(ns_entries) - 1] will explode. Reported-by: Richard Weinberger <richard@nod.at> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Daniel Lezcano <daniel.lezcano@free.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc-ns: use d_set_d_op() API to set dentry ops in proc_ns_instantiate().Pravin B Shelar2012-03-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | The namespace cleanup path leaks a dentry which holds a reference count on a network namespace. Keeping that network namespace from being freed when the last user goes away. Leaving things like vlan devices in the leaked network namespace. If you use ip netns add for much real work this problem becomes apparent pretty quickly. It light testing the problem hides because frequently you simply don't notice the leak. Use d_set_d_op() so that DCACHE_OP_* flags are set correctly. This issue exists back to 3.0. Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Reported-by: Justin Pettit <jpettit@nicira.com> Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: Jesse Gross <jesse@nicira.com> Cc: David Miller <davem@davemloft.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: trim includes a bitAl Viro2012-01-031-1/+0
| | | | | | [folded fix for missing magic.h from Tetsuo Handa] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* proc: Fix Oops on stat of /proc/<zombie pid>/ns/netEric W. Biederman2011-06-151-3/+6
| | | | | | | | | | Don't call iput with the inode half setup to be a namespace filedescriptor. Instead rearrange the code so that we don't initialize ei->ns_ops until after I ns_ops->get succeeds, preventing us from invoking ns_ops->put when ns_ops->get failed. Reported-by: Ingo Saitz <Ingo.Saitz@stud.uni-hannover.de> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* ns proc: Return -ENOENT for a nonexistent /proc/self/ns/ entry.Eric W. Biederman2011-05-241-0/+1
| | | | | Spotted-by: Nathan Lynch <ntl@pobox.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* ns proc: Add support for the ipc namespaceEric W. Biederman2011-05-101-0/+3
| | | | | Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* ns proc: Add support for the uts namespaceEric W. Biederman2011-05-101-0/+3
| | | | | Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* ns proc: Add support for the network namespace.Eric W. Biederman2011-05-101-0/+3
| | | | | | | | | Implementing file descriptors for the network namespace is simple and straight forward. Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* ns: proc files for namespace naming policy.Eric W. Biederman2011-05-101-0/+188
Create files under /proc/<pid>/ns/ to allow controlling the namespaces of a process. This addresses three specific problems that can make namespaces hard to work with. - Namespaces require a dedicated process to pin them in memory. - It is not possible to use a namespace unless you are the child of the original creator. - Namespaces don't have names that userspace can use to talk about them. The namespace files under /proc/<pid>/ns/ can be opened and the file descriptor can be used to talk about a specific namespace, and to keep the specified namespace alive. A namespace can be kept alive by either holding the file descriptor open or bind mounting the file someplace else. aka: mount --bind /proc/self/ns/net /some/filesystem/path mount --bind /proc/self/fd/<N> /some/filesystem/path This allows namespaces to be named with userspace policy. It requires additional support to make use of these filedescriptors and that will be comming in the following patches. Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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