When reading /proc/pid/numa_maps, it's possible to return the contents of
the stack where the mempolicy string should be printed if the policy gets
freed from beneath us.

This happens because mpol_to_str() may return an error the
stack-allocated buffer is then printed without ever being stored.

There are two possible error conditions in mpol_to_str():

 - if the buffer allocated is insufficient for the string to be stored,
   and

 - if the mempolicy has an invalid mode.

The first error condition is not triggered in any of the callers to
mpol_to_str(): at least 50 bytes is always allocated on the stack and this
is sufficient for the string to be written.  A future patch should convert
this into BUILD_BUG_ON() since we know the maximum strlen possible, but
that's not -rc material.

The second error condition is possible if a race occurs in dropping a
reference to a task's mempolicy causing it to be freed during the read().
The slab poison value is then used for the mode and mpol_to_str() returns
-EINVAL.

This race is only possible because get_vma_policy() believes that
mm->mmap_sem protects task->mempolicy, which isn't true.  The exit path
does not hold mm->mmap_sem when dropping the reference or setting
task->mempolicy to NULL: it uses task_lock(task) instead.

Thus, it's required for the caller of a task mempolicy to hold
task_lock(task) while grabbing the mempolicy and reading it.  Callers with
a vma policy store their mempolicy earlier and can simply increment the
reference count so it's guaranteed not to be freed.
Reported-by: NDave Jones <davej@redhat.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

replace_fd() began with "eats a reference, tries to insert into
descriptor table" semantics; at some point I'd switched it to
much saner current behaviour ("try to insert into descriptor
table, grabbing a new reference if inserted; caller should do
fput() in any case"), but forgot to update the callers.
Mea culpa...

[Spotted by Pavel Roskin, who has really weird system with pipe-fed
coredumps as part of what he considers a normal boot ;-)]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

In the common case where a name is much smaller than PATH_MAX, an extra
allocation for struct filename is unnecessary. Before allocating a
separate one, try to embed the struct filename inside the buffer first. If
it turns out that that's not long enough, then fall back to allocating a
separate struct filename and redoing the copy.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

...and fix up the callers. For do_file_open_root, just declare a
struct filename on the stack and fill out the .name field. For
do_filp_open, make it also take a struct filename pointer, and fix up its
callers to call it appropriately.

For filp_open, add a variant that takes a struct filename pointer and turn
filp_open into a wrapper around it.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

...and make the user_path callers use that variant instead.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Currently, if we call getname() on a userland string more than once,
we'll get multiple copies of the string and multiple audit_names
records.

Add a function that will allow the audit_names code to satisfy getname
requests using info from the audit_names list, avoiding a new allocation
and audit_names records.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl 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: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

When compiling with user namespace support btrfs fails like:

fs/btrfs/tree-log.c: In function ‘fill_inode_item’:
fs/btrfs/tree-log.c:2955:2: error: incompatible type for argument 3 of ‘btrfs_set_inode_uid’
fs/btrfs/ctree.h:2026:1: note: expected ‘u32’ but argument is of type ‘kuid_t’
fs/btrfs/tree-log.c:2956:2: error: incompatible type for argument 3 of ‘btrfs_set_inode_gid’
fs/btrfs/ctree.h:2027:1: note: expected ‘u32’ but argument is of type ‘kgid_t’

Fix this by using i_uid_read and i_gid_read in

Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

The code needs to be from_kgid(make_kgid(...)...) not
from_kuid(make_kgid(...)...). Doh!
Reported-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

I see no callers in module code.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

In order to accomodate retrying path-based syscalls, we need to add a
new "type" argument to audit_inode_child. This will tell us whether
we're looking for a child entry that represents a create or a delete.

If we find a parent, don't automatically assume that we need to create a
new entry. Instead, use the information we have to try to find an
existing entry first. Update it if one is found and create a new one if
not.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl 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: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Most of the callers get called with an inode and dentry in the reverse
order. The compiler then has to reshuffle the arg registers and/or
stack in order to pass them on to audit_inode_child.

Reverse those arguments for a micro-optimization.
Reported-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

As best I can tell, whenever retval == 0, nd->path.dentry and nd->inode
are also non-NULL. Eliminate those checks and the superfluous
audit_context check.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The follow_link() function always initializes its *p argument,
or returns an error, but when building with 'gcc -s', the compiler
gets confused by the __always_inline attribute to the function
and can no longer detect where the cookie was initialized.

The solution is to always initialize the pointer from follow_link,
even in the error path. When building with -O2, this has zero impact
on generated code and adds a single instruction in the error path
for a -Os build on ARM.

Without this patch, building with gcc-4.6 through gcc-4.8 and
CONFIG_CC_OPTIMIZE_FOR_SIZE results in:

fs/namei.c: In function 'link_path_walk':
fs/namei.c:649:24: warning: 'cookie' may be used uninitialized in this function [-Wuninitialized]
fs/namei.c:1544:9: note: 'cookie' was declared here
fs/namei.c: In function 'path_lookupat':
fs/namei.c:649:24: warning: 'cookie' may be used uninitialized in this function [-Wuninitialized]
fs/namei.c:1934:10: note: 'cookie' was declared here
fs/namei.c: In function 'path_openat':
fs/namei.c:649:24: warning: 'cookie' may be used uninitialized in this function [-Wuninitialized]
fs/namei.c:2899:9: note: 'cookie' was declared here
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

In autofs4_d_automount(), if a mount fail occurs the AUTOFS_INF_PENDING
mount pending flag is not cleared.

One effect of this is when using the "browse" option, directory entry
attributes show up with all "?"s due to the incorrect callback and
subsequent failure return (when in fact no callback should be made).
Signed-off-by: NIan Kent <ikent@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When the lglock doesn't need to be exported we can use
DEFINE_STATIC_LGLOCK().
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Fuzzing with trinity oopsed on the 1st instruction of shmem_fh_to_dentry(),
	u64 inum = fid->raw[2];
which is unhelpfully reported as at the end of shmem_alloc_inode():

BUG: unable to handle kernel paging request at ffff880061cd3000
IP: [<ffffffff812190d0>] shmem_alloc_inode+0x40/0x40
Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Call Trace:
 [<ffffffff81488649>] ? exportfs_decode_fh+0x79/0x2d0
 [<ffffffff812d77c3>] do_handle_open+0x163/0x2c0
 [<ffffffff812d792c>] sys_open_by_handle_at+0xc/0x10
 [<ffffffff83a5f3f8>] tracesys+0xe1/0xe6

Right, tmpfs is being stupid to access fid->raw[2] before validating that
fh_len includes it: the buffer kmalloc'ed by do_sys_name_to_handle() may
fall at the end of a page, and the next page not be present.

But some other filesystems (ceph, gfs2, isofs, reiserfs, xfs) are being
careless about fh_len too, in fh_to_dentry() and/or fh_to_parent(), and
could oops in the same way: add the missing fh_len checks to those.
Reported-by: NSasha Levin <levinsasha928@gmail.com>
Signed-off-by: NHugh Dickins <hughd@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Sage Weil <sage@inktank.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Removed s_lock from super_block and removed lock/unlock super.
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Removed lock/unlock super. Added a new private s_lock mutex.
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Removed lock/unlock super. Added a new private s_lock mutex.
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Removed lock/unlock super.
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Acked-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Removed lock/unlock super. Added a new private s_lock mutex.
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Removed lock/unlock super.
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Removed lock/unlock super.
Acked-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

I have tested the attached patch to fix the dup3 regression.

Rich.

From 0944e30e12dec6544b3602626b60ff412375c78f Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Tue, 9 Oct 2012 14:42:45 +0100
Subject: [PATCH] dup3: Return an error when oldfd == newfd.

The following commit:

  commit fe17f22d
  Author: Al Viro <viro@zeniv.linux.org.uk>
  Date:   Tue Aug 21 11:48:11 2012 -0400

    take purely descriptor-related stuff from fcntl.c to file.c

was supposed to be just code motion, but it dropped the following two
lines:

  if (unlikely(oldfd == newfd))
          return -EINVAL;

from the dup3 system call.  dup3 is not specified by POSIX, so Linux
can do what it likes.  However the POSIX proposal for dup3 [1] states
that it should return an error if oldfd == newfd.

[1] http://austingroupbugs.net/view.php?id=411Signed-off-by: NRichard W.M. Jones <rjones@redhat.com>
Tested-by: NRichard W.M. Jones <rjones@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit "fs: add link restriction audit reporting" has added auditing of failed
attempts to follow symlinks. Unfortunately, the auditing was being done after
the struct path structure was released earlier.
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

PRJQUOTA value of quota type should never reach need_print_warning() since XFS
(which is the only fs which uses that type) doesn't use generic functions
calling this function. Anyway, add PRJQUOTA case to the switch to make gcc
happy.
Signed-off-by: NJan Kara <jack@suse.cz>

parse_options() in ext3 should return 0 when parse the mount options fails.
Signed-off-by: NZhao Hongjiang <zhaohongjiang@huawei.com>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: NJan Kara <jack@suse.cz>

parse_options() in ext2 should return 0 when parse the mount options fails.
Signed-off-by: NZhao Hongjiang <zhaohongjiang@huawei.com>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: NJan Kara <jack@suse.cz>

This is the ext3 version of the same patch applied to Ext4, where such goal is
to audit the usage of ext3_bread() due a possible misinterpretion of its return
value.

Focused on directory blocks, a NULL value returned from ext3_bread() means a
hole, which cannot exist into a directory inode. It can pass undetected after a
fix in an uninitialized error variable.

The (now) initialized variable into ext3_getblk() may lead to a zero'ed return
value of ext3_bread() to its callers, which can make the caller do not detect
the hole in the directory inode.

This patch creates a new wrapper function ext3_dir_bread() which checks for
holes properly, reports error, and returns EIO in that case.
Signed-off-by: NCarlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: NJan Kara <jack@suse.cz>

This is a backport of ext4 commit 90b0a973 which fixes a possible
non-initialized variable on htree_dirblock_to_tree().
Ext3 has the same non initialized variable, but, in any case it will be
initialized by ext3_get_blocks_handle(), which will avoid the bug to be
triggered, but, the non-initialized variable by htree_dirblock_to_tree() is
still a bug.
Signed-off-by: NCarlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: NJan Kara <jack@suse.cz>

In case of error, the function get_inode() returns ERR_PTR().
But the users hppfs_lookup() and hppfs_fill_super() use NULL
test for check the return value, not IS_ERR(), so we'd better
change the return value of get_inode() to NULL instead of
ERR_PTR().

dpatch engine is used to generated this patch.
(https://github.com/weiyj/dpatch)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Removed vmtruncate.
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NChris Mason <chris.mason@fusionio.com>

In csum_dirty_buffer, we first get eb from page->private.
Then we check if the page is the first page of eb. Later
we check it again. Remove the repeated check here.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>