Problem with ioctl() is that it's a file operation, yet often used as an
inode operation (i.e. modify the inode despite the file being opened for
read-only).
mnt_want_write_file() is used by filesystems in such cases to get write
access on an arbitrary open file.
Since overlayfs lets filesystems do all file operations, including ioctl,
this can lead to mnt_want_write_file() returning OK for a lower file and
modification of that lower file.
This patch prevents modification by checking if the file is from an
overlayfs lower layer and returning EPERM in that case.
Need to introduce a mnt_want_write_file_path() variant that still does the
old thing for inode operations that can do the copy up + modification
correctly in such cases (fchown, fsetxattr, fremovexattr).
This does not address the correctness of such ioctls on overlayfs (the
correct way would be to copy up and attempt to perform ioctl on upper
file).
In theory this could be a regression. We very much hope that nobody is
relying on such a hack in any sane setup.
While this patch meddles in VFS code, it has no effect on non-overlayfs
filesystems.
Reported-by: "zhangyi (F)" <yi.zhang@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Root in a non-initial user ns cannot be trusted to write a traditional
security.capability xattr. If it were allowed to do so, then any
unprivileged user on the host could map his own uid to root in a private
namespace, write the xattr, and execute the file with privilege on the
host.
However supporting file capabilities in a user namespace is very
desirable. Not doing so means that any programs designed to run with
limited privilege must continue to support other methods of gaining and
dropping privilege. For instance a program installer must detect
whether file capabilities can be assigned, and assign them if so but set
setuid-root otherwise. The program in turn must know how to drop
partial capabilities, and do so only if setuid-root.
This patch introduces v3 of the security.capability xattr. It builds a
vfs_ns_cap_data struct by appending a uid_t rootid to struct
vfs_cap_data. This is the absolute uid_t (that is, the uid_t in user
namespace which mounted the filesystem, usually init_user_ns) of the
root id in whose namespaces the file capabilities may take effect.
When a task asks to write a v2 security.capability xattr, if it is
privileged with respect to the userns which mounted the filesystem, then
nothing should change. Otherwise, the kernel will transparently rewrite
the xattr as a v3 with the appropriate rootid. This is done during the
execution of setxattr() to catch user-space-initiated capability writes.
Subsequently, any task executing the file which has the noted kuid as
its root uid, or which is in a descendent user_ns of such a user_ns,
will run the file with capabilities.
Similarly when asking to read file capabilities, a v3 capability will
be presented as v2 if it applies to the caller's namespace.
If a task writes a v3 security.capability, then it can provide a uid for
the xattr so long as the uid is valid in its own user namespace, and it
is privileged with CAP_SETFCAP over its namespace. The kernel will
translate that rootid to an absolute uid, and write that to disk. After
this, a task in the writer's namespace will not be able to use those
capabilities (unless rootid was 0), but a task in a namespace where the
given uid is root will.
Only a single security.capability xattr may exist at a time for a given
file. A task may overwrite an existing xattr so long as it is
privileged over the inode. Note this is a departure from previous
semantics, which required privilege to remove a security.capability
xattr. This check can be re-added if deemed useful.
This allows a simple setxattr to work, allows tar/untar to work, and
allows us to tar in one namespace and untar in another while preserving
the capability, without risking leaking privilege into a parent
namespace.
Example using tar:
$ cp /bin/sleep sleepx
$ mkdir b1 b2
$ lxc-usernsexec -m b:0:100000:1 -m b:1:$(id -u):1 -- chown 0:0 b1
$ lxc-usernsexec -m b:0:100001:1 -m b:1:$(id -u):1 -- chown 0:0 b2
$ lxc-usernsexec -m b:0:100000:1000 -- tar --xattrs-include=security.capability --xattrs -cf b1/sleepx.tar sleepx
$ lxc-usernsexec -m b:0:100001:1000 -- tar --xattrs-include=security.capability --xattrs -C b2 -xf b1/sleepx.tar
$ lxc-usernsexec -m b:0:100001:1000 -- getcap b2/sleepx
b2/sleepx = cap_sys_admin+ep
# /opt/ltp/testcases/bin/getv3xattr b2/sleepx
v3 xattr, rootid is 100001
A patch to linux-test-project adding a new set of tests for this
functionality is in the nsfscaps branch at github.com/hallyn/ltp
Changelog:
Nov 02 2016: fix invalid check at refuse_fcap_overwrite()
Nov 07 2016: convert rootid from and to fs user_ns
(From ebiederm: mar 28 2017)
commoncap.c: fix typos - s/v4/v3
get_vfs_caps_from_disk: clarify the fs_ns root access check
nsfscaps: change the code split for cap_inode_setxattr()
Apr 09 2017:
don't return v3 cap for caps owned by current root.
return a v2 cap for a true v2 cap in non-init ns
Apr 18 2017:
. Change the flow of fscap writing to support s_user_ns writing.
. Remove refuse_fcap_overwrite(). The value of the previous
xattr doesn't matter.
Apr 24 2017:
. incorporate Eric's incremental diff
. move cap_convert_nscap to setxattr and simplify its usage
May 8, 2017:
. fix leaking dentry refcount in cap_inode_getsecurity
Signed-off-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
There are many code paths opencoding kvmalloc. Let's use the helper
instead. The main difference to kvmalloc is that those users are
usually not considering all the aspects of the memory allocator. E.g.
allocation requests <= 32kB (with 4kB pages) are basically never failing
and invoke OOM killer to satisfy the allocation. This sounds too
disruptive for something that has a reasonable fallback - the vmalloc.
On the other hand those requests might fallback to vmalloc even when the
memory allocator would succeed after several more reclaim/compaction
attempts previously. There is no guarantee something like that happens
though.
This patch converts many of those places to kv[mz]alloc* helpers because
they are more conservative.
Link: http://lkml.kernel.org/r/20170306103327.2766-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Xen bits
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Andreas Dilger <andreas.dilger@intel.com> # Lustre
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> # KVM/s390
Acked-by: Dan Williams <dan.j.williams@intel.com> # nvdim
Acked-by: David Sterba <dsterba@suse.com> # btrfs
Acked-by: Ilya Dryomov <idryomov@gmail.com> # Ceph
Acked-by: Tariq Toukan <tariqt@mellanox.com> # mlx4
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx5
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Santosh Raspatur <santosh@chelsio.com>
Cc: Hariprasad S <hariprasad@chelsio.com>
Cc: Yishai Hadas <yishaih@mellanox.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: "Yan, Zheng" <zyan@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
getxattr uses vmalloc to allocate memory if kzalloc fails. This is
filled by vfs_getxattr and then copied to the userspace. vmalloc,
however, doesn't zero out the memory so if the specific implementation
of the xattr handler is sloppy we can theoretically expose a kernel
memory. There is no real sign this is really the case but let's make
sure this will not happen and use vzalloc instead.
Fixes: 779302e678 ("fs/xattr.c:getxattr(): improve handling of allocation failures")
Link: http://lkml.kernel.org/r/20170306103327.2766-1-mhocko@kernel.org
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org> [3.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The IOP_XATTR flag is set on sockfs because sockfs supports getting the
"system.sockprotoname" xattr. Since commit 6c6ef9f2, this flag is checked for
setxattr support as well. This is wrong on sockfs because security xattr
support there is supposed to be provided by security_inode_setsecurity. The
smack security module relies on socket labels (xattrs).
Fix this by adding a security xattr handler on sockfs that returns
-EAGAIN, and by checking for -EAGAIN in setxattr.
We cannot simply check for -EOPNOTSUPP in setxattr because there are
filesystems that neither have direct security xattr support nor support
via security_inode_setsecurity. A more proper fix might be to move the
call to security_inode_setsecurity into sockfs, but it's not clear to me
if that is safe: we would end up calling security_inode_post_setxattr after
that as well.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
These inode operations are no longer used; remove them.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
All filesystems that support xattrs by now do so via xattr handlers.
They all define sb->s_xattr, and their getxattr, setxattr, and
removexattr inode operations use the generic inode operations. On
filesystems that don't support xattrs, the xattr inode operations are
all NULL, and sb->s_xattr is also NULL.
This means that we can remove the getxattr, setxattr, and removexattr
inode operations and directly call the generic handlers, or better,
inline expand those handlers into fs/xattr.c.
Filesystems that do not support xattrs on some inodes should clear the
IOP_XATTR i_opflags flag in those inodes. (Right now, some filesystems
have checks to disable xattrs on some inodes in the ->list, ->get, and
->set xattr handler operations instead.) The IOP_XATTR flag is
automatically cleared in inodes of filesystems that don't have xattr
support.
In orangefs, symlinks do have a setxattr iop but no getxattr iop. Add a
check for symlinks to orangefs_inode_getxattr to preserve the current,
weird behavior; that check may not be necessary though.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When an inode doesn't support xattrs, turn listxattr off as well.
(When xattrs are "turned off", the VFS still passes security xattr
operations through to security modules, which can still expose inode
security labels that way.)
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Right now, various places in the kernel check for the existence of
getxattr, setxattr, and removexattr inode operations and directly call
those operations. Switch to helper functions and test for the IOP_XATTR
flag instead.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
With this change, all the xattr handler based operations will produce an
-EIO result for bad inodes, and we no longer only depend on inode->i_op
to be set to bad_inode_ops.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The IOP_XATTR inode operations flag in inode->i_opflags indicates that
the inode has xattr support. The flag is automatically set by
new_inode() on filesystems with xattr support (where sb->s_xattr is
defined), and cleared otherwise. Filesystems can explicitly clear it
for inodes that should not have xattr support.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When NULL is passed to one of the xattr system calls as the attribute
name, copying that name from user space already fails with -EFAULT;
xattr_resolve_name is never called with a NULL attribute name.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When a filesystem outside of init_user_ns is mounted it could have
uids and gids stored in it that do not map to init_user_ns.
The plan is to allow those filesystems to set i_uid to INVALID_UID and
i_gid to INVALID_GID for unmapped uids and gids and then to handle
that strange case in the vfs to ensure there is consistent robust
handling of the weirdness.
Upon a careful review of the vfs and filesystems about the only case
where there is any possibility of confusion or trouble is when the
inode is written back to disk. In that case filesystems typically
read the inode->i_uid and inode->i_gid and write them to disk even
when just an inode timestamp is being updated.
Which leads to a rule that is very simple to implement and understand
inodes whose i_uid or i_gid is not valid may not be written.
In dealing with access times this means treat those inodes as if the
inode flag S_NOATIME was set. Reads of the inodes appear safe and
useful, but any write or modification is disallowed. The only inode
write that is allowed is a chown that sets the uid and gid on the
inode to valid values. After such a chown the inode is normal and may
be treated as such.
Denying all writes to inodes with uids or gids unknown to the vfs also
prevents several oddball cases where corruption would have occurred
because the vfs does not have complete information.
One problem case that is prevented is attempting to use the gid of a
directory for new inodes where the directories sgid bit is set but the
directories gid is not mapped.
Another problem case avoided is attempting to update the evm hash
after setxattr, removexattr, and setattr. As the evm hash includeds
the inode->i_uid or inode->i_gid not knowning the uid or gid prevents
a correct evm hash from being computed. evm hash verification also
fails when i_uid or i_gid is unknown but that is essentially harmless
as it does not cause filesystem corruption.
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.
Similar change for ->getxattr() had been done in commit ce23e64. Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit 98e9cb57 improved the xattr name checks in xattr_resolve_name but
didn't update the NULL attribute name check appropriately, so NULL
attribute names lead to NULL pointer dereferences. Turn that into
-EINVAL results instead.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
fs/xattr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The code could leak xattrs->lock on error.
Problem introduced with 786534b92f "tmpfs: listxattr should
include POSIX ACL xattrs".
Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).
Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull misc vfs updates from Al Viro:
"All kinds of stuff. That probably should've been 5 or 6 separate
branches, but by the time I'd realized how large and mixed that bag
had become it had been too close to -final to play with rebasing.
Some fs/namei.c cleanups there, memdup_user_nul() introduction and
switching open-coded instances, burying long-dead code, whack-a-mole
of various kinds, several new helpers for ->llseek(), assorted
cleanups and fixes from various people, etc.
One piece probably deserves special mention - Neil's
lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets
called without ->i_mutex and tries to avoid ever taking it. That, of
course, means that it's not useful for any directory modifications,
but things like getting inode attributes in nfds readdirplus are fine
with that. I really should've asked for moratorium on lookup-related
changes this cycle, but since I hadn't done that early enough... I
*am* asking for that for the coming cycle, though - I'm going to try
and get conversion of i_mutex to rwsem with ->lookup() done under lock
taken shared.
There will be a patch closer to the end of the window, along the lines
of the one Linus had posted last May - mechanical conversion of
->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
inode_is_locked()/inode_lock_nested(). To quote Linus back then:
-----
| This is an automated patch using
|
| sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
| sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
| sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
| sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
| sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
|
| with a very few manual fixups
-----
I'm going to send that once the ->i_mutex-affecting stuff in -next
gets mostly merged (or when Linus says he's about to stop taking
merges)"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
nfsd: don't hold i_mutex over userspace upcalls
fs:affs:Replace time_t with time64_t
fs/9p: use fscache mutex rather than spinlock
proc: add a reschedule point in proc_readfd_common()
logfs: constify logfs_block_ops structures
fcntl: allow to set O_DIRECT flag on pipe
fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
fs: xattr: Use kvfree()
[s390] page_to_phys() always returns a multiple of PAGE_SIZE
nbd: use ->compat_ioctl()
fs: use block_device name vsprintf helper
lib/vsprintf: add %*pg format specifier
fs: use gendisk->disk_name where possible
poll: plug an unused argument to do_poll
amdkfd: don't open-code memdup_user()
cdrom: don't open-code memdup_user()
rsxx: don't open-code memdup_user()
mtip32xx: don't open-code memdup_user()
[um] mconsole: don't open-code memdup_user_nul()
[um] hostaudio: don't open-code memdup_user()
...
Change the list operation to only return whether or not an attribute
should be listed. Copying the attribute names into the buffer is moved
to the callers.
Since the result only depends on the dentry and not on the attribute
name, we do not pass the attribute name to list operations.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add a nfs_listxattr operation. Move the call to security_inode_listsecurity
from list operation of the "security.*" xattr handler to nfs_listxattr.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When a file on tmpfs has an ACL or a Default ACL, listxattr should include the
corresponding xattr name.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Use the VFS xattr handler infrastructure and get rid of similar code in
the filesystem. For implementing shmem_xattr_handler_set, we need a
version of simple_xattr_set which removes the attribute when value is
NULL. Use this to implement kernfs_iop_removexattr as well.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add an additional "name" field to struct xattr_handler. When the name
is set, the handler matches attributes with exactly that name. When the
prefix is set instead, the handler matches attributes with the given
prefix and with a non-empty suffix.
This patch should avoid bugs like the one fixed in commit c361016a in
the future.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This function was only briefly used in security/integrity/evm, between
commits 66dbc325 and 15647eb3.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that the xattr handler is passed to the xattr handler operations, we
can use the same get and set operations for the user, trusted, and security
xattr namespaces. In those namespaces, we can access the full attribute
name by "reattaching" the name prefix the vfs has skipped for us. Add a
xattr_full_name helper to make this obvious in the code.
For the "system.posix_acl_access" and "system.posix_acl_default"
attributes, handler->prefix is the full attribute name; the suffix is the
empty string.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: v9fs-developer@lists.sourceforge.net
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The xattr_handler operations are currently all passed a file system
specific flags value which the operations can use to disambiguate between
different handlers; some file systems use that to distinguish the xattr
namespace, for example. In some oprations, it would be useful to also have
access to the handler prefix. To allow that, pass a pointer to the handler
to operations instead of the flags value alone.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
EVM needs to be atomically updated when removing xattrs.
Otherwise concurrent EVM verification may fail in between.
This patch fixes by moving i_mutex unlocking after calling
EVM hook. fsnotify_xattr() is also now called while locked
the same way as it is done in __vfs_setxattr_noperm.
Changelog:
- remove unused 'inode' variable.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
... for situations when we don't have any candidate in pathnames - basically,
in descriptor-based syscalls.
[Folded the build fix for !CONFIG_AUDITSYSCALL configs from Chen Gang]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The following pairs of system calls dealing with extended attributes only
differ in their behavior on whether the symbolic link is followed (when
the named file is a symbolic link):
- setxattr() and lsetxattr()
- getxattr() and lgetxattr()
- listxattr() and llistxattr()
- removexattr() and lremovexattr()
Despite this, the implementations all had duplicated code, so this commit
redirects each of the above pairs of system calls to a corresponding
function to which different lookup flags (LOOKUP_FOLLOW or 0) are passed.
For me this reduced the stripped size of xattr.o from 8824 to 8248 bytes.
Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If a filesystem uses simple_xattr to support user extended attributes,
LTP setxattr01 and xfstests generic/062 fail with "Cannot allocate
memory": simple_xattr_alloc()'s wrap-around test mistakenly excludes
values of zero size. Fix that off-by-one (but apparently no filesystem
needs them yet).
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 38f3865744 ("xattr: extract simple_xattr code from tmpfs") moved
some code from tmpfs but introduced a subtle bug along the way.
If the name passed to simple_xattr_remove() does not exist in the list of
xattrs, then it is possible to call kfree(new_xattr) when new_xattr is
actually initialized to itself on the stack via uninitialized_var().
This causes a BUG() since the memory was not allocated via the slab
allocator and was not bypassed through to the page allocator because it
was too large.
Initialize the local variable to NULL so the kfree() never takes place.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Pull security subsystem updates from James Morris:
"Highlights:
- Integrity: add local fs integrity verification to detect offline
attacks
- Integrity: add digital signature verification
- Simple stacking of Yama with other LSMs (per LSS discussions)
- IBM vTPM support on ppc64
- Add new driver for Infineon I2C TIS TPM
- Smack: add rule revocation for subject labels"
Fixed conflicts with the user namespace support in kernel/auditsc.c and
security/integrity/ima/ima_policy.c.
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (39 commits)
Documentation: Update git repository URL for Smack userland tools
ima: change flags container data type
Smack: setprocattr memory leak fix
Smack: implement revoking all rules for a subject label
Smack: remove task_wait() hook.
ima: audit log hashes
ima: generic IMA action flag handling
ima: rename ima_must_appraise_or_measure
audit: export audit_log_task_info
tpm: fix tpm_acpi sparse warning on different address spaces
samples/seccomp: fix 31 bit build on s390
ima: digital signature verification support
ima: add support for different security.ima data types
ima: add ima_inode_setxattr/removexattr function and calls
ima: add inode_post_setattr call
ima: replace iint spinblock with rwlock/read_lock
ima: allocating iint improvements
ima: add appraise action keywords and default rules
ima: integrity appraisal extension
vfs: move ima_file_free before releasing the file
...
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
...
- In setxattr if we are setting a posix acl convert uids and gids from
the current user namespace into the initial user namespace, before
the xattrs are passed to the underlying filesystem.
Untranslatable uids and gids are represented as -1 which
posix_acl_from_xattr will represent as INVALID_UID or INVALID_GID.
posix_acl_valid will fail if an acl from userspace has any
INVALID_UID or INVALID_GID values. In net this guarantees that
untranslatable posix acls will not be stored by filesystems.
- In getxattr if we are reading a posix acl convert uids and gids from
the initial user namespace into the current user namespace.
Uids and gids that can not be tranlsated into the current user namespace
will be represented as -1.
- Replace e_id in struct posix_acl_entry with an anymouns union of
e_uid and e_gid. For the short term retain the e_id field
until all of the users are converted.
- Don't set struct posix_acl.e_id in the cases where the acl type
does not use e_id. Greatly reducing the use of ACL_UNDEFINED_ID.
- Rework the ordering checks in posix_acl_valid so that I use kuid_t
and kgid_t types throughout the code, and so that I don't need
arithmetic on uid and gid types.
Cc: Theodore Tso <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
new_xattr in __simple_xattr_set() is only initialized with a valid
pointer if value is not NULL, which only happens if this function is
called directly with the intention to remove an existing extended
attribute. Even being safe to be this way, smatch warns about possible
NULL dereference. Dan Carpenter suggested using uninitialized_var()
which will make both gcc and smatch happy.
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
v2: add function documentation instead of adding a separate file under
Documentation/
tj: Updated comment a bit and rolled in Randy's suggestions.
Cc: Li Zefan <lizefan@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Lennart Poettering <lpoetter@redhat.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This patch takes the i_mutex lock before security_inode_removexattr(),
instead of after, in preparation of calling ima_inode_removexattr().
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
Extract in-memory xattr APIs from tmpfs. Will be used by cgroup.
$ size vmlinux.o
text data bss dec hex filename
4658782 880729 5195032 10734543 a3cbcf vmlinux.o
$ size vmlinux.o
text data bss dec hex filename
4658957 880729 5195032 10734718 a3cc7e vmlinux.o
v7:
- checkpatch warnings fixed
- Implement the changes requested by Hugh Dickins:
- make simple_xattrs_init and simple_xattrs_free inline
- get rid of locking and list reinitialization in simple_xattrs_free,
they're not needed
v6:
- no changes
v5:
- no changes
v4:
- move simple_xattrs_free() to fs/xattr.c
v3:
- in kmem_xattrs_free(), reinitialize the list
- use simple_xattr_* prefix
- introduce simple_xattr_add() to prevent direct list usage
Original-patch-by: Li Zefan <lizefan@huawei.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Lennart Poettering <lpoetter@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This allocation can be as large as 64k.
- Add __GFP_NOWARN so the falied kmalloc() is silent
- Fall back to vmalloc() if the kmalloc() failed
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This allocation can be as large as 64k.
- Add __GFP_NOWARN so the a falied kmalloc() is silent
- Fall back to vmalloc() if the kmalloc() failed
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: David Rientjes <rientjes@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This allocation can be as large as 64k. As David points out, "falling
back to vmalloc here is much better solution than failing to retreive
the attribute - it will work no matter how fragmented memory gets. That
means we don't get incomplete backups occurring after days or months of
uptime and successful backups".
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: David Rientjes <rientjes@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This size is user controllable, up to a maximum of XATTR_LIST_MAX (64k).
So it's trivial for someone to trigger a stream of order:4 page
allocation errors.
Signed-off-by: Dave Jones <davej@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include. Fix up any implicit
include dependencies that were being masked by module.h along
the way.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
vfs_getxattr_alloc() and vfs_xattr_cmp() are two new kernel xattr helper
functions. vfs_getxattr_alloc() first allocates memory for the requested
xattr and then retrieves it. vfs_xattr_cmp() compares a given value with
the contents of an extended attribute.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Some recent benchmarking on btrfs showed that a major scaling bottleneck
on large systems on btrfs is currently the xattr lookup on every write.
Why xattr lookup on every write I hear you ask?
write wants to drop suid and security related xattrs that could set o
capabilities for executables. To do that it currently looks up
security.capability on EVERY write (even for non executables) to decide
whether to drop it or not.
In btrfs this causes an additional tree walk, hitting some per file system
locks and quite bad scalability. In a simple read workload on a 8S
system I saw over 90% CPU time in spinlocks related to that.
Chris Mason tells me this is also a problem in ext4, where it hits
the global mbcache lock.
This patch adds a simple per inode to avoid this problem. We only
do the lookup once per file and then if there is no xattr cache
the decision. All xattr changes clear the flag.
I also used the same flag to avoid the suid check, although
that one is pretty cheap.
A file system can also set this flag when it creates the inode,
if it has a cheap way to do so. This is done for some common file systems
in followon patches.
With this patch a major part of the lock contention disappears
for btrfs. Some testing on smaller systems didn't show significant
performance changes, but at least it helps the larger systems
and is generally more efficient.
v2: Rename is_sgid. add file system helper.
Cc: chris.mason@oracle.com
Cc: josef@redhat.com
Cc: viro@zeniv.linux.org.uk
Cc: agruen@linbit.com
Cc: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Return -ENODATA when trying to read a user.* attribute which cannot
exist: user space otherwise does not have a reasonable way to
distinguish between non-existent and inaccessible attributes.
Likewise, return -ENODATA when an unprivileged process tries to read a
trusted.* attribute: to unprivileged processes, those attributes are
invisible (listxattr() won't include them).
Related to this bug report: https://bugzilla.redhat.com/660613
Signed-off-by: Andreas Gruenbacher <agruen@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
For some reason generic_setxattr() did not pass flags (XATTR_CREATE,
XATTR_REPLACE) to the filesystem specific helper. This caused that
setxattr(2) syscall just ignored these flags.
Fix the bug by passing flags correctly.
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
And give it a kernel-doc comment.
[akpm@linux-foundation.org: btrfs changed in linux-next]
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The entries in xattr handler table should be immutable (ie const)
like other operation tables.
Later patches convert common filesystems. Uncoverted filesystems
will still work, but will generate a compiler warning.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add a flags argument to struct xattr_handler and pass it to all xattr
handler methods. This allows using the same methods for multiple
handlers, e.g. for the ACL methods which perform exactly the same action
for the access and default ACLs, just using a different underlying
attribute. With a little more groundwork it'll also allow sharing the
methods for the regular user/trusted/secure handlers in extN, ocfs2 and
jffs2 like it's already done for xfs in this patch.
Also change the inode argument to the handlers to a dentry to allow
using the handlers mechnism for filesystems that require it later,
e.g. cifs.
[with GFS2 bits updated by Steven Whitehouse <swhiteho@redhat.com>]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This factors out the part of the vfs_setxattr function that performs the
setting of the xattr and its notification. This is needed so the SELinux
implementation of inode_setsecctx can handle the setting of the xattr while
maintaining the proper separation of layers.
Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
This patch speeds up lmbench lat_mmap test by about another 2% after the
first patch.
Before:
avg = 462.286
std = 5.46106
After:
avg = 453.12
std = 9.58257
(50 runs of each, stddev gives a reasonable confidence)
It does this by introducing mnt_clone_write, which avoids some heavyweight
operations of mnt_want_write if called on a vfsmount which we know already
has a write count; and mnt_want_write_file, which can call mnt_clone_write
if the file is open for write.
After these two patches, mnt_want_write and mnt_drop_write go from 7% on
the profile down to 1.3% (including mnt_clone_write).
[AV: mnt_want_write_file() should take file alone and derive mnt from it;
not only all callers have that form, but that's the only mnt about which
we know that it's already held for write if file is opened for write]
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Convert all system calls to return a long. This should be a NOP since all
converted types should have the same size anyway.
With the exception of sys_exit_group which returned void. But that doesn't
matter since the system call doesn't return.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
We used to have rather schizophrenic set of checks for NULL ->i_op even
though it had been eliminated years ago. You'd need to go out of your
way to set it to NULL explicitly _and_ a bunch of code would die on
such inodes anyway. After killing two remaining places that still
did that bogosity, all that crap can go away.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* do not pass nameidata; struct path is all the callers want.
* switch to new helpers:
user_path_at(dfd, pathname, flags, &path)
user_path(pathname, &path)
user_lpath(pathname, &path)
user_path_dir(pathname, &path) (fail if not a directory)
The last 3 are trivial macro wrappers for the first one.
* remove nameidata in callers.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add missing consts to xattr function arguments.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This basically audits the callers of xattr_permission(), which calls
permission() and can perform writes to the filesystem.
[AV: add missing parts - removexattr() and nfsd posix acls, plug for a leak
spotted by Miklos]
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Add path_put() functions for releasing a reference to the dentry and
vfsmount of a struct path in the right order
* Switch from path_release(nd) to path_put(&nd->path)
* Rename dput_path() to path_put_conditional()
[akpm@linux-foundation.org: fix cifs]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.
Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
<dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
struct path in every place where the stack can be traversed
- it reduces the overall code size:
without patch series:
text data bss dec hex filename
5321639 858418 715768 6895825 6938d1 vmlinux
with patch series:
text data bss dec hex filename
5320026 858418 715768 6894212 693284 vmlinux
This patch:
Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Originally vfs_getxattr would pull the security xattr variable using
the inode getxattr handle and then proceed to clobber it with a subsequent call
to the LSM.
This patch reorders the two operations such that when the xattr requested is
in the security namespace it first attempts to grab the value from the LSM
directly.
If it fails to obtain the value because there is no module present or the
module does not support the operation it will fall back to using the inode
getxattr operation.
In the event that both are inaccessible it returns EOPNOTSUPP.
Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch modifies the interface to inode_getsecurity to have the function
return a buffer containing the security blob and its length via parameters
instead of relying on the calling function to give it an appropriately sized
buffer.
Security blobs obtained with this function should be freed using the
release_secctx LSM hook. This alleviates the problem of the caller having to
guess a length and preallocate a buffer for this function allowing it to be
used elsewhere for Labeled NFS.
The patch also removed the unused err parameter. The conversion is similar to
the one performed by Al Viro for the security_getprocattr hook.
Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce is_owner_or_cap() macro in fs.h, and convert over relevant
users to it. This is done because we want to avoid bugs in the future
where we check for only effective fsuid of the current task against a
file's owning uid, without simultaneously checking for CAP_FOWNER as
well, thus violating its semantics.
[ XFS uses special macros and structures, and in general looked ...
untouchable, so we leave it alone -- but it has been looked over. ]
The (current->fsuid != inode->i_uid) check in generic_permission() and
exec_permission_lite() is left alone, because those operations are
covered by CAP_DAC_OVERRIDE and CAP_DAC_READ_SEARCH. Similarly operations
falling under the purview of CAP_CHOWN and CAP_LEASE are also left alone.
Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Cc: Al Viro <viro@ftp.linux.org.uk>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Collect inode info for the remaining xattr syscalls that operate on a file
descriptor. These don't call a path_lookup variant, so they aren't covered by
the general audit hook.
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch changes struct file to use struct path instead of having
independent pointers to struct dentry and struct vfsmount, and converts all
users of f_{dentry,vfsmnt} in fs/ to use f_path.{dentry,mnt}.
Additionally, it adds two #define's to make the transition easier for users of
the f_dentry and f_vfsmnt.
Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The user.* extended attributes are only allowed on regular files and
directories. Sticky directories further restrict write access to the owner
and privileged users. (See the attr(5) man page for an explanation.)
The original check in ext2/ext3 when user.* xattrs were merged was more
restrictive than intended, and when the xattr permission checks were moved
into the VFS, read access to user.* attributes on sticky directores ended
up being denied in addition.
Originally-from: Gerard Neil <xyzzy@devferret.org>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch moves code out of fs/xattr.c:listxattr into a new function -
vfs_listxattr. The code for vfs_listxattr was originally submitted by Bill
Nottingham <notting@redhat.com> to Unionfs.
Sorry about that. The reason for this submission is to make the
listxattr code in fs/xattr.c a little cleaner (as well as to clean up
some code in Unionfs.)
Currently, Unionfs has vfs_listxattr defined in its code. I think
that's very ugly, and I'd like to see it (re)moved. The logical place
to put it, is along side of all the other vfs_*xattr functions.
Overall, I think this patch is benefitial for both kernel.org kernel and
Unionfs.
Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch augments the collection of inode info during syscall
processing. It represents part of the functionality that was provided
by the auditfs patch included in RHEL4.
Specifically, it:
- Collects information for target inodes created or removed during
syscalls. Previous code only collects information for the target
inode's parent.
- Adds the audit_inode() hook to syscalls that operate on a file
descriptor (e.g. fchown), enabling audit to do inode filtering for
these calls.
- Modifies filtering code to check audit context for either an inode #
or a parent inode # matching a given rule.
- Modifies logging to provide inode # for both parent and child.
- Protect debug info from NULL audit_names.name.
[AV: folded a later typo fix from the same author]
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
)
From: Christoph Hellwig <hch@lst.de>
The xattr code has rather complex permission checks because the rules are very
different for different attribute namespaces. This patch moves as much as we
can into the generic code. Currently all the major disk based filesystems
duplicate these checks, while many minor filesystems or network filesystems
lack some or all of them.
To do this we need defines for the extended attribute names in common code, I
moved them up from JFS which had the nicest defintions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add vfs_getxattr, vfs_setxattr and vfs_removexattr helpers for common checks
around invocation of the xattr methods. NFSD already was missing some of the
checks and there will be more soon.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: James Morris <jmorris@namei.org>
(James, I haven't touched selinux yet because it's doing various odd things
and I'm not sure how it would interact with the security attribute fallbacks
you added. Could you investigate whether it could use vfs_getxattr or if not
add a __vfs_getxattr helper to share the bits it is fine with?)
For NFSv4: instead of just converting it add an nfsd_getxattr helper for the
code shared by NFSv2/3 and NFSv4 ACLs. In fact that code isn't even
NFS-specific, but I'll wait for more users to pop up first before moving it to
common code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.
Modified-by: Ingo Molnar <mingo@elte.hu>
(finished the conversion)
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit f549d6c18c introduced a generic
fallback for security xattrs, but appears to include a subtle bug.
Gentoo users with kernels with selinux compiled in, and coreutils compiled
with acl support, noticed that they could not copy files on tmpfs using
'cp'.
cp (compiled with acl support) copies the file, lists the extended
attributes on the old file, copies them all to the new file, and then
exits. However the listxattr() calls were failing with this odd behaviour:
llistxattr("a.out", (nil), 0) = 17
llistxattr("a.out", 0x7fffff8c6cb0, 17) = -1 ERANGE (Numerical result out of
range)
I believe this is a simple problem in the logic used to check the buffer
sizes; if the user sends a buffer the exact size of the data, then its ok
:)
This change solves the problem.
More info can be found at http://bugs.gentoo.org/113138
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
