linux-stable.git/fs/gfs2, branch linux-3.16.y Linux kernel stable tree GFS2: don't set rgrp gl_object until it's inserted into rgrp tree 2019-09-23T20:12:08+00:00 Bob Peterson rpeterso@redhat.com 2016-06-09T19:24:07+00:00 b0699c8e33f2fdf5396da2d41cf2f7ffe9a140a9 commit 36e4ad0316c017d5b271378ed9a1c9a4b77fab5f upstream. Before this patch, function read_rindex_entry would set a rgrp glock's gl_object pointer to itself before inserting the rgrp into the rgrp rbtree. The problem is: if another process was also reading the rgrp in, and had already inserted its newly created rgrp, then the second call to read_rindex_entry would overwrite that value, then return a bad return code to the caller. Later, other functions would reference the now-freed rgrp memory by way of gl_object. In some cases, that could result in gfs2_rgrp_brelse being called twice for the same rgrp: once for the failed attempt and once for the "real" rgrp release. Eventually the kernel would panic. There are also a number of other things that could go wrong when a kernel module is accessing freed storage. For example, this could result in rgrp corruption because the fake rgrp would point to a fake bitmap in memory too, causing gfs2_inplace_reserve to search some random memory for free blocks, and find some, since we were never setting rgd->rd_bits to NULL before freeing it. This patch fixes the problem by not setting gl_object until we have successfully inserted the rgrp into the rbtree. Also, it sets rd_bits to NULL as it frees them, which will ensure any accidental access to the wrong rgrp will result in a kernel panic rather than file system corruption, which is preferred. Signed-off-by: Bob Peterson <rpeterso@redhat.com> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 36e4ad0316c017d5b271378ed9a1c9a4b77fab5f upstream.

Before this patch, function read_rindex_entry would set a rgrp
glock's gl_object pointer to itself before inserting the rgrp into
the rgrp rbtree. The problem is: if another process was also reading
the rgrp in, and had already inserted its newly created rgrp, then
the second call to read_rindex_entry would overwrite that value,
then return a bad return code to the caller. Later, other functions
would reference the now-freed rgrp memory by way of gl_object.
In some cases, that could result in gfs2_rgrp_brelse being called
twice for the same rgrp: once for the failed attempt and once for
the "real" rgrp release. Eventually the kernel would panic.
There are also a number of other things that could go wrong when
a kernel module is accessing freed storage. For example, this could
result in rgrp corruption because the fake rgrp would point to a
fake bitmap in memory too, causing gfs2_inplace_reserve to search
some random memory for free blocks, and find some, since we were
never setting rgd->rd_bits to NULL before freeing it.

This patch fixes the problem by not setting gl_object until we
have successfully inserted the rgrp into the rbtree. Also, it sets
rd_bits to NULL as it frees them, which will ensure any accidental
access to the wrong rgrp will result in a kernel panic rather than
file system corruption, which is preferred.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
GFS2: Fix rgrp end rounding problem for bsize < page size 2019-09-23T20:12:07+00:00 Bob Peterson rpeterso@redhat.com 2015-10-28T14:05:31+00:00 a7e905eaaf4a08b7ff65f43607f8a64a5175c643 commit 31dddd9eb9ebae9a2a9b502750e9e481d752180a upstream. This patch fixes a bug introduced by commit 7005c3e. That patch tries to map a vm range for resource groups, but the calculation breaks down when the block size is less than the page size. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 31dddd9eb9ebae9a2a9b502750e9e481d752180a upstream.

This patch fixes a bug introduced by commit 7005c3e. That patch
tries to map a vm range for resource groups, but the calculation
breaks down when the block size is less than the page size.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
gfs2_meta: ->mount() can get NULL dev_name 2019-02-11T17:53:31+00:00 Al Viro viro@zeniv.linux.org.uk 2018-10-13T04:19:13+00:00 01d94e303007444851812be4052f16dbbd8fa025 commit 3df629d873f8683af6f0d34dfc743f637966d483 upstream. get in sync with mount_bdev() handling of the same Reported-by: syzbot+c54f8e94e6bba03b04e9@syzkaller.appspotmail.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 3df629d873f8683af6f0d34dfc743f637966d483 upstream.

get in sync with mount_bdev() handling of the same

Reported-by: syzbot+c54f8e94e6bba03b04e9@syzkaller.appspotmail.com
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mm: drop vm_ops->remap_pages and generic_file_remap_pages() stub 2018-10-03T03:09:51+00:00 Kirill A. Shutemov kirill.shutemov@linux.intel.com 2015-02-10T22:09:54+00:00 ae347f225e91a960c61f7470a3b21bcb4ea5fcfa commit d83a08db5ba6072caa658745881f4baa9bad6a08 upstream. Nobody uses it anymore. [akpm@linux-foundation.org: fix filemap_xip.c] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.16: - Deleted code is slightly different - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit d83a08db5ba6072caa658745881f4baa9bad6a08 upstream.

Nobody uses it anymore.

[akpm@linux-foundation.org: fix filemap_xip.c]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16:
 - Deleted code is slightly different
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
gfs2: remove IS_ERR_VALUE abuse 2017-11-11T13:33:43+00:00 Arnd Bergmann arnd@arndb.de 2017-05-05T19:46:28+00:00 ebb4ccde90e52413b5a11e624e176825f4f1fe57 Picked from commit 287980e49ffc0f6d911601e7e352a812ed27768e ("remove lots of IS_ERR_VALUE abuses") upstream. The original fix that was backported to 3.18 already addressed the warning in some configurations, but not in others, leaving us with the same output: ../fs/gfs2/dir.c: In function 'get_first_leaf': ../fs/gfs2/dir.c:768:9: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized] error = get_leaf(dip, leaf_no, bh_out); ^ ../fs/gfs2/dir.c: In function 'dir_split_leaf.isra.20': ../fs/gfs2/dir.c:987:8: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized] This takes the approach that we took in later versions in mainline, but does not backport the entire patch, as that would be too large for stable and IIRC caused regressions in other drivers. Fixes: 9d46d31e9aea ("gfs2: avoid uninitialized variable warning") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
Picked from commit 287980e49ffc0f6d911601e7e352a812ed27768e ("remove lots
of IS_ERR_VALUE abuses") upstream.

The original fix that was backported to 3.18 already addressed the warning
in some configurations, but not in others, leaving us with the same output:

../fs/gfs2/dir.c: In function 'get_first_leaf':
../fs/gfs2/dir.c:768:9: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]
   error = get_leaf(dip, leaf_no, bh_out);
         ^
../fs/gfs2/dir.c: In function 'dir_split_leaf.isra.20':
../fs/gfs2/dir.c:987:8: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]

This takes the approach that we took in later versions in mainline,
but does not backport the entire patch, as that would be too large
for stable and IIRC caused regressions in other drivers.

Fixes: 9d46d31e9aea ("gfs2: avoid uninitialized variable warning")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
fs: Give dentry to inode_change_ok() instead of inode 2017-02-23T03:53:52+00:00 Jan Kara jack@suse.cz 2016-05-26T14:55:18+00:00 50b070e8224f7bf86622ede1abee9fa3d3dc2f10 commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream. inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> [bwh: Backported to 3.16: - Drop changes to orangefs, overlayfs - Adjust filenames, context - In nfsd, pass dentry to nfsd_sanitize_attrs() - Update ext3 as well] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream.

inode_change_ok() will be resposible for clearing capabilities and IMA
extended attributes and as such will need dentry. Give it as an argument
to inode_change_ok() instead of an inode. Also rename inode_change_ok()
to setattr_prepare() to better relect that it does also some
modifications in addition to checks.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
[bwh: Backported to 3.16:
 - Drop changes to orangefs, overlayfs
 - Adjust filenames, context
 - In nfsd, pass dentry to nfsd_sanitize_attrs()
 - Update ext3 as well]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Revert "fs: Give dentry to inode_change_ok() instead of inode" 2017-02-23T03:53:52+00:00 Ben Hutchings ben@decadent.org.uk 2016-11-30T23:13:05+00:00 1c608c2d1aefca2bf63497663e17cfb49e6b022c This reverts commit be9df699432235753c3824b0f5a27d46de7fdc9e, which was commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream. The backport breaks fuse and makes a mess of xfs, which can be improved by picking further upstream commits as I should have done in the first place. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
This reverts commit be9df699432235753c3824b0f5a27d46de7fdc9e, which was
commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream.  The backport
breaks fuse and makes a mess of xfs, which can be improved by picking
further upstream commits as I should have done in the first place.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
posix_acl: Clear SGID bit when setting file permissions 2016-11-20T01:17:38+00:00 Jan Kara jack@suse.cz 2016-09-19T15:39:09+00:00 f2ba3e2310b3967720b83126db8684c69ce41894 commit 073931017b49d9458aa351605b43a7e34598caef upstream. When file permissions are modified via chmod(2) and the user is not in the owning group or capable of CAP_FSETID, the setgid bit is cleared in inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file permissions as well as the new ACL, but doesn't clear the setgid bit in a similar way; this allows to bypass the check in chmod(2). Fix that. References: CVE-2016-7097 Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> [bwh: Backported to 3.16: - Drop changes to orangefs - Adjust context - Update ext3 as well] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 073931017b49d9458aa351605b43a7e34598caef upstream.

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok().  Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2).  Fix that.

References: CVE-2016-7097
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
[bwh: Backported to 3.16:
 - Drop changes to orangefs
 - Adjust context
 - Update ext3 as well]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
fs: Give dentry to inode_change_ok() instead of inode 2016-11-20T01:17:38+00:00 Jan Kara jack@suse.cz 2016-05-26T14:55:18+00:00 be9df699432235753c3824b0f5a27d46de7fdc9e commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream. inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> [bwh: Backported to 3.16: - Drop changes to orangefs, overlayfs - Adjust filenames, context - In fuse, pass dentry to fuse_do_setattr() - In nfsd, pass dentry to nfsd_sanitize_attrs() - In xfs, pass dentry to xfs_setattr_nonsize() and xfs_setattr_size() - Update ext3 as well] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 31051c85b5e2aaaf6315f74c72a732673632a905 upstream.

inode_change_ok() will be resposible for clearing capabilities and IMA
extended attributes and as such will need dentry. Give it as an argument
to inode_change_ok() instead of an inode. Also rename inode_change_ok()
to setattr_prepare() to better relect that it does also some
modifications in addition to checks.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
[bwh: Backported to 3.16:
 - Drop changes to orangefs, overlayfs
 - Adjust filenames, context
 - In fuse, pass dentry to fuse_do_setattr()
 - In nfsd, pass dentry to nfsd_sanitize_attrs()
 - In xfs, pass dentry to xfs_setattr_nonsize() and xfs_setattr_size()
 - Update ext3 as well]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
fs: create and use seq_show_option for escaping 2015-09-29T15:44:47+00:00 Kees Cook keescook@chromium.org 2015-09-04T22:44:57+00:00 7cf259c95caa9de7238fafeb0cd252e445b42c07 commit a068acf2ee77693e0bf39d6e07139ba704f461c3 upstream. Many file systems that implement the show_options hook fail to correctly escape their output which could lead to unescaped characters (e.g. new lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files. This could lead to confusion, spoofed entries (resulting in things like systemd issuing false d-bus "mount" notifications), and who knows what else. This looks like it would only be the root user stepping on themselves, but it's possible weird things could happen in containers or in other situations with delegated mount privileges. Here's an example using overlay with setuid fusermount trusting the contents of /proc/mounts (via the /etc/mtab symlink). Imagine the use of "sudo" is something more sneaky: $ BASE="ovl" $ MNT="$BASE/mnt" $ LOW="$BASE/lower" $ UP="$BASE/upper" $ WORK="$BASE/work/ 0 0 none /proc fuse.pwn user_id=1000" $ mkdir -p "$LOW" "$UP" "$WORK" $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt $ cat /proc/mounts none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0 none /proc fuse.pwn user_id=1000 0 0 $ fusermount -u /proc $ cat /proc/mounts cat: /proc/mounts: No such file or directory This fixes the problem by adding new seq_show_option and seq_show_option_n helpers, and updating the vulnerable show_option handlers to use them as needed. Some, like SELinux, need to be open coded due to unusual existing escape mechanisms. [akpm@linux-foundation.org: add lost chunk, per Kees] [keescook@chromium.org: seq_show_option should be using const parameters] Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Jan Kara <jack@suse.com> Acked-by: Paul Moore <paul@paul-moore.com> Cc: J. R. Okajima <hooanon05g@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [ luis: backported to 3.16: - dropped changes to fs/overlayfs/super.c, net/ceph/ceph_common.c and to cgroup_show_options() in kernel/cgroup.c - adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@canonical.com> 
commit a068acf2ee77693e0bf39d6e07139ba704f461c3 upstream.

Many file systems that implement the show_options hook fail to correctly
escape their output which could lead to unescaped characters (e.g.  new
lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files.  This
could lead to confusion, spoofed entries (resulting in things like
systemd issuing false d-bus "mount" notifications), and who knows what
else.  This looks like it would only be the root user stepping on
themselves, but it's possible weird things could happen in containers or
in other situations with delegated mount privileges.

Here's an example using overlay with setuid fusermount trusting the
contents of /proc/mounts (via the /etc/mtab symlink).  Imagine the use
of "sudo" is something more sneaky:

  $ BASE="ovl"
  $ MNT="$BASE/mnt"
  $ LOW="$BASE/lower"
  $ UP="$BASE/upper"
  $ WORK="$BASE/work/ 0 0
  none /proc fuse.pwn user_id=1000"
  $ mkdir -p "$LOW" "$UP" "$WORK"
  $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt
  $ cat /proc/mounts
  none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0
  none /proc fuse.pwn user_id=1000 0 0
  $ fusermount -u /proc
  $ cat /proc/mounts
  cat: /proc/mounts: No such file or directory

This fixes the problem by adding new seq_show_option and
seq_show_option_n helpers, and updating the vulnerable show_option
handlers to use them as needed.  Some, like SELinux, need to be open
coded due to unusual existing escape mechanisms.

[akpm@linux-foundation.org: add lost chunk, per Kees]
[keescook@chromium.org: seq_show_option should be using const parameters]
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Jan Kara <jack@suse.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Cc: J. R. Okajima <hooanon05g@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ luis: backported to 3.16:
  - dropped changes to fs/overlayfs/super.c, net/ceph/ceph_common.c and to
    cgroup_show_options() in kernel/cgroup.c
  - adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>