Pull (again) user namespace infrastructure changes from Eric Biederman:
"Those bugs, those darn embarrasing bugs just want don't want to get
fixed.
Linus I just updated my mirror of your kernel.org tree and it appears
you successfully pulled everything except the last 4 commits that fix
those embarrasing bugs.
When you get a chance can you please repull my branch"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
userns: Fix typo in description of the limitation of userns_install
userns: Add a more complete capability subset test to commit_creds
userns: Require CAP_SYS_ADMIN for most uses of setns.
Fix cap_capable to only allow owners in the parent user namespace to have caps.
Pull user namespace changes from Eric Biederman:
"While small this set of changes is very significant with respect to
containers in general and user namespaces in particular. The user
space interface is now complete.
This set of changes adds support for unprivileged users to create user
namespaces and as a user namespace root to create other namespaces.
The tyranny of supporting suid root preventing unprivileged users from
using cool new kernel features is broken.
This set of changes completes the work on setns, adding support for
the pid, user, mount namespaces.
This set of changes includes a bunch of basic pid namespace
cleanups/simplifications. Of particular significance is the rework of
the pid namespace cleanup so it no longer requires sending out
tendrils into all kinds of unexpected cleanup paths for operation. At
least one case of broken error handling is fixed by this cleanup.
The files under /proc/<pid>/ns/ have been converted from regular files
to magic symlinks which prevents incorrect caching by the VFS,
ensuring the files always refer to the namespace the process is
currently using and ensuring that the ptrace_mayaccess permission
checks are always applied.
The files under /proc/<pid>/ns/ have been given stable inode numbers
so it is now possible to see if different processes share the same
namespaces.
Through the David Miller's net tree are changes to relax many of the
permission checks in the networking stack to allowing the user
namespace root to usefully use the networking stack. Similar changes
for the mount namespace and the pid namespace are coming through my
tree.
Two small changes to add user namespace support were commited here adn
in David Miller's -net tree so that I could complete the work on the
/proc/<pid>/ns/ files in this tree.
Work remains to make it safe to build user namespaces and 9p, afs,
ceph, cifs, coda, gfs2, ncpfs, nfs, nfsd, ocfs2, and xfs so the
Kconfig guard remains in place preventing that user namespaces from
being built when any of those filesystems are enabled.
Future design work remains to allow root users outside of the initial
user namespace to mount more than just /proc and /sys."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (38 commits)
proc: Usable inode numbers for the namespace file descriptors.
proc: Fix the namespace inode permission checks.
proc: Generalize proc inode allocation
userns: Allow unprivilged mounts of proc and sysfs
userns: For /proc/self/{uid,gid}_map derive the lower userns from the struct file
procfs: Print task uids and gids in the userns that opened the proc file
userns: Implement unshare of the user namespace
userns: Implent proc namespace operations
userns: Kill task_user_ns
userns: Make create_new_namespaces take a user_ns parameter
userns: Allow unprivileged use of setns.
userns: Allow unprivileged users to create new namespaces
userns: Allow setting a userns mapping to your current uid.
userns: Allow chown and setgid preservation
userns: Allow unprivileged users to create user namespaces.
userns: Ignore suid and sgid on binaries if the uid or gid can not be mapped
userns: fix return value on mntns_install() failure
vfs: Allow unprivileged manipulation of the mount namespace.
vfs: Only support slave subtrees across different user namespaces
vfs: Add a user namespace reference from struct mnt_namespace
...
Andy Lutomirski <luto@amacapital.net> found a nasty little bug in
the permissions of setns. With unprivileged user namespaces it
became possible to create new namespaces without privilege.
However the setns calls were relaxed to only require CAP_SYS_ADMIN in
the user nameapce of the targed namespace.
Which made the following nasty sequence possible.
pid = clone(CLONE_NEWUSER | CLONE_NEWNS);
if (pid == 0) { /* child */
system("mount --bind /home/me/passwd /etc/passwd");
}
else if (pid != 0) { /* parent */
char path[PATH_MAX];
snprintf(path, sizeof(path), "/proc/%u/ns/mnt");
fd = open(path, O_RDONLY);
setns(fd, 0);
system("su -");
}
Prevent this possibility by requiring CAP_SYS_ADMIN
in the current user namespace when joing all but the user namespace.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
There was some desire in large applications using MAP_HUGETLB or
SHM_HUGETLB to use 1GB huge pages on some mappings, and stay with 2MB on
others. This is useful together with NUMA policy: use 2MB interleaving
on some mappings, but 1GB on local mappings.
This patch extends the IPC/SHM syscall interfaces slightly to allow
specifying the page size.
It borrows some upper bits in the existing flag arguments and allows
encoding the log of the desired page size in addition to the *_HUGETLB
flag. When 0 is specified the default size is used, this makes the
change fully compatible.
Extending the internal hugetlb code to handle this is straight forward.
Instead of a single mount it just keeps an array of them and selects the
right mount based on the specified page size. When no page size is
specified it uses the mount of the default page size.
The change is not visible in /proc/mounts because internal mounts don't
appear there. It also has very little overhead: the additional mounts
just consume a super block, but not more memory when not used.
I also exported the new flags to the user headers (they were previously
under __KERNEL__). Right now only symbols for x86 and some other
architecture for 1GB and 2MB are defined. The interface should already
work for all other architectures though. Only architectures that define
multiple hugetlb sizes actually need it (that is currently x86, tile,
powerpc). However tile and powerpc have user configurable hugetlb
sizes, so it's not easy to add defines. A program on those
architectures would need to query sysfs and use the appropiate log2.
[akpm@linux-foundation.org: cleanups]
[rientjes@google.com: fix build]
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Modify create_new_namespaces to explicitly take a user namespace
parameter, instead of implicitly through the task_struct.
This allows an implementation of unshare(CLONE_NEWUSER) where
the new user namespace is not stored onto the current task_struct
until after all of the namespaces are created.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
- Push the permission check from the core setns syscall into
the setns install methods where the user namespace of the
target namespace can be determined, and used in a ns_capable
call.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Keep a pointer to the audit_names "slot" in struct filename.
Have all of the audit_inode callers pass a struct filename ponter to
audit_inode instead of a string pointer. If the aname field is already
populated, then we can skip walking the list altogether and just use it
directly.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
getname() is intended to copy pathname strings from userspace into a
kernel buffer. The result is just a string in kernel space. It would
however be quite helpful to be able to attach some ancillary info to
the string.
For instance, we could attach some audit-related info to reduce the
amount of audit-related processing needed. When auditing is enabled,
we could also call getname() on the string more than once and not
need to recopy it from userspace.
This patchset converts the getname()/putname() interfaces to return
a struct instead of a string. For now, the struct just tracks the
string in kernel space and the original userland pointer for it.
Later, we'll add other information to the struct as it becomes
convenient.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently, this gets set mostly by happenstance when we call into
audit_inode_child. While that might be a little more efficient, it seems
wrong. If the syscall ends up failing before audit_inode_child ever gets
called, then you'll have an audit_names record that shows the full path
but has the parent inode info attached.
Fix this by passing in a parent flag when we call audit_inode that gets
set to the value of LOOKUP_PARENT. We can then fix up the pathname for
the audit entry correctly from the get-go.
While we're at it, clean up the no-op macro for audit_inode in the
!CONFIG_AUDITSYSCALL case.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit d6629859b3 ("ipc/mqueue: improve performance of send/recv") and
ce2d52cc ("ipc/mqueue: add rbtree node caching support") introduced an
rbtree of message priorities, and usage of rb_init_node() to initialize
the corresponding nodes. As it turns out, rb_init_node() is unnecessary
here, as the nodes are fully initialized on insertion by rb_link_node()
and the code doesn't access nodes that aren't inserted on the rbtree.
Removing the rb_init_node() calls as I removed that function during
rbtree API cleanups (the only other use of it was in a place that
similarly didn't require it).
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs update from Al Viro:
- big one - consolidation of descriptor-related logics; almost all of
that is moved to fs/file.c
(BTW, I'm seriously tempted to rename the result to fd.c. As it is,
we have a situation when file_table.c is about handling of struct
file and file.c is about handling of descriptor tables; the reasons
are historical - file_table.c used to be about a static array of
struct file we used to have way back).
A lot of stray ends got cleaned up and converted to saner primitives,
disgusting mess in android/binder.c is still disgusting, but at least
doesn't poke so much in descriptor table guts anymore. A bunch of
relatively minor races got fixed in process, plus an ext4 struct file
leak.
- related thing - fget_light() partially unuglified; see fdget() in
there (and yes, it generates the code as good as we used to have).
- also related - bits of Cyrill's procfs stuff that got entangled into
that work; _not_ all of it, just the initial move to fs/proc/fd.c and
switch of fdinfo to seq_file.
- Alex's fs/coredump.c spiltoff - the same story, had been easier to
take that commit than mess with conflicts. The rest is a separate
pile, this was just a mechanical code movement.
- a few misc patches all over the place. Not all for this cycle,
there'll be more (and quite a few currently sit in akpm's tree)."
Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
MAX_LFS_FILESIZE should be a loff_t
compat: fs: Generic compat_sys_sendfile implementation
fs: push rcu_barrier() from deactivate_locked_super() to filesystems
btrfs: reada_extent doesn't need kref for refcount
coredump: move core dump functionality into its own file
coredump: prevent double-free on an error path in core dumper
usb/gadget: fix misannotations
fcntl: fix misannotations
ceph: don't abuse d_delete() on failure exits
hypfs: ->d_parent is never NULL or negative
vfs: delete surplus inode NULL check
switch simple cases of fget_light to fdget
new helpers: fdget()/fdput()
switch o2hb_region_dev_write() to fget_light()
proc_map_files_readdir(): don't bother with grabbing files
make get_file() return its argument
vhost_set_vring(): turn pollstart/pollstop into bool
switch prctl_set_mm_exe_file() to fget_light()
switch xfs_find_handle() to fget_light()
switch xfs_swapext() to fget_light()
...
Pull user namespace changes from Eric Biederman:
"This is a mostly modest set of changes to enable basic user namespace
support. This allows the code to code to compile with user namespaces
enabled and removes the assumption there is only the initial user
namespace. Everything is converted except for the most complex of the
filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs,
nfs, ocfs2 and xfs as those patches need a bit more review.
The strategy is to push kuid_t and kgid_t values are far down into
subsystems and filesystems as reasonable. Leaving the make_kuid and
from_kuid operations to happen at the edge of userspace, as the values
come off the disk, and as the values come in from the network.
Letting compile type incompatible compile errors (present when user
namespaces are enabled) guide me to find the issues.
The most tricky areas have been the places where we had an implicit
union of uid and gid values and were storing them in an unsigned int.
Those places were converted into explicit unions. I made certain to
handle those places with simple trivial patches.
Out of that work I discovered we have generic interfaces for storing
quota by projid. I had never heard of the project identifiers before.
Adding full user namespace support for project identifiers accounts
for most of the code size growth in my git tree.
Ultimately there will be work to relax privlige checks from
"capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing
root in a user names to do those things that today we only forbid to
non-root users because it will confuse suid root applications.
While I was pushing kuid_t and kgid_t changes deep into the audit code
I made a few other cleanups. I capitalized on the fact we process
netlink messages in the context of the message sender. I removed
usage of NETLINK_CRED, and started directly using current->tty.
Some of these patches have also made it into maintainer trees, with no
problems from identical code from different trees showing up in
linux-next.
After reading through all of this code I feel like I might be able to
win a game of kernel trivial pursuit."
Fix up some fairly trivial conflicts in netfilter uid/git logging code.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits)
userns: Convert the ufs filesystem to use kuid/kgid where appropriate
userns: Convert the udf filesystem to use kuid/kgid where appropriate
userns: Convert ubifs to use kuid/kgid
userns: Convert squashfs to use kuid/kgid where appropriate
userns: Convert reiserfs to use kuid and kgid where appropriate
userns: Convert jfs to use kuid/kgid where appropriate
userns: Convert jffs2 to use kuid and kgid where appropriate
userns: Convert hpfs to use kuid and kgid where appropriate
userns: Convert btrfs to use kuid/kgid where appropriate
userns: Convert bfs to use kuid/kgid where appropriate
userns: Convert affs to use kuid/kgid wherwe appropriate
userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids
userns: On ia64 deal with current_uid and current_gid being kuid and kgid
userns: On ppc convert current_uid from a kuid before printing.
userns: Convert s390 getting uid and gid system calls to use kuid and kgid
userns: Convert s390 hypfs to use kuid and kgid where appropriate
userns: Convert binder ipc to use kuids
userns: Teach security_path_chown to take kuids and kgids
userns: Add user namespace support to IMA
userns: Convert EVM to deal with kuids and kgids in it's hmac computation
...
- Store the ipc owner and creator with a kuid
- Store the ipc group and the crators group with a kgid.
- Add error handling to ipc_update_perms, allowing it to
fail if the uids and gids can not be converted to kuids
or kgids.
- Modify the proc files to display the ipc creator and
owner in the user namespace of the opener of the proc file.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
The msgsnd and msgrcv system calls use size_t to represent the size of the
message being transferred. POSIX states that values of msgsz greater than
SSIZE_MAX cause the result to be implementation-defined. On Linux, this
equates to returning -EINVAL if (long) msgsz < 0.
For compat tasks where !CONFIG_ARCH_WANT_OLD_COMPAT_IPC and compat_size_t
is smaller than size_t, negative size values passed from userspace will be
interpreted as positive values by do_msg{rcv,snd} and will fail to exit
early with -EINVAL.
This patch changes the compat prototypes for msg{rcv,snd} so that the
message size is represented as a compat_ssize_t, which we cast to the
native ssize_t type for the core IPC code.
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 48b25c43e6 ("ipc: provide generic compat versions of IPC
syscalls") added a new ARCH_WANT_OLD_COMPAT_IPC config option for
architectures to select if their compat target requires the old IPC
syscall interface.
For architectures (such as AArch64) that do not require the internal
calling conventions provided by this option, but have a compat target
where the C library passes the IPC_64 flag explicitly,
compat_ipc_parse_version no longer strips out the flag before calling
the native system call implementation, resulting in unknown SHM/IPC
commands and -EINVAL being returned to userspace.
This patch separates the selection of the internal calling conventions
for the IPC syscalls from the version parsing, allowing architectures to
select __ARCH_WANT_COMPAT_IPC_PARSE_VERSION if they want to use version
parsing whilst retaining the newer syscall calling conventions.
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the SHMLBA definition for a native task differs from the definition for
a compat task, the do_shmat() function would need to handle both.
This patch introduces COMPAT_SHMLBA, which is used by the compat shmat
syscall when calling the ipc code and allows architectures such as AArch64
(where the native SHMLBA is 64k but the compat (AArch32) definition is
16k) to provide the correct semantics for compat IPC system calls.
Cc: David S. Miller <davem@davemloft.net>
Cc: Chris Zankel <chris@zankel.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
boolean "does it have to be exclusive?" flag is passed instead;
Local filesystem should just ignore it - the object is guaranteed
not to be there yet.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit 17cf28afea ("mm/fs: remove truncate_range") removed the
truncate_range inode operation in favour of the fallocate file
operation.
When using SYSV IPC shared memory segments, calling madvise with the
MADV_REMOVE advice on an area of shared memory will attempt to invoke
the .fallocate function for the shm_file_operations, which is NULL and
therefore returns -EOPNOTSUPP to userspace. The previous behaviour
would inherit the inode_operations from the underlying tmpfs file and
invoke truncate_range there.
This patch restores the previous behaviour by wrapping the underlying
fallocate function in shm_fallocate, as we do for fsync.
[hughd@google.com: use -ENOTSUPP in shm_fallocate()]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
