linux-stable.git/fs/inode.c, branch linux-3.16.y

futex: Fix inode life-time issue

2020-04-28T18:03:51+00:00

commit 8019ad13ef7f64be44d4f892af9c840179009254 upstream.

As reported by Jann, ihold() does not in fact guarantee inode
persistence. And instead of making it so, replace the usage of inode
pointers with a per boot, machine wide, unique inode identifier.

This sequence number is global, but shared (file backed) futexes are
rare enough that this should not become a performance issue.

Reported-by: Jann Horn 
Suggested-by: Linus Torvalds 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.16: Use atomic64_cmpxchg() instead of the
 _relaxed() variant which we don't have]
Signed-off-by: Ben Hutchings

rmap: drop support of non-linear mappings

2018-10-03T03:09:51+00:00

commit 27ba0644ea9dfe6e7693abc85837b60e40583b96 upstream.

We don't create non-linear mappings anymore.  Let's drop code which
handles them in rmap.

Signed-off-by: Kirill A. Shutemov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
[bwh: Backported to 3.16:
 - Deleted code is slightly different
 - Adjust context]
Signed-off-by: Ben Hutchings

Fix up non-directory creation in SGID directories

2018-09-25T22:47:29+00:00

commit 0fa3ecd87848c9c93c2c828ef4c3a8ca36ce46c7 upstream.

sgid directories have special semantics, making newly created files in
the directory belong to the group of the directory, and newly created
subdirectories will also become sgid.  This is historically used for
group-shared directories.

But group directories writable by non-group members should not imply
that such non-group members can magically join the group, so make sure
to clear the sgid bit on non-directories for non-members (but remember
that sgid without group execute means "mandatory locking", just to
confuse things even more).

Reported-by: Jann Horn 
Cc: Andy Lutomirski 
Cc: Al Viro 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

fs: Fix S_NOSEC handling

2015-07-15T09:00:50+00:00

commit 2426f3910069ed47c0cc58559a6d088af7920201 upstream.

file_remove_suid() could mistakenly set S_NOSEC inode bit when root was
modifying the file. As a result following writes to the file by ordinary
user would avoid clearing suid or sgid bits.

Fix the bug by checking actual mode bits before setting S_NOSEC.

Signed-off-by: Jan Kara 
Signed-off-by: Al Viro 
Signed-off-by: Luis Henriques

fs,userns: Change inode_capable to capable_wrt_inode_uidgid

2014-06-10T20:57:22+00:00

The kernel has no concept of capabilities with respect to inodes; inodes
exist independently of namespaces.  For example, inode_capable(inode,
CAP_LINUX_IMMUTABLE) would be nonsense.

This patch changes inode_capable to check for uid and gid mappings and
renames it to capable_wrt_inode_uidgid, which should make it more
obvious what it does.

Fixes CVE-2014-4014.

Cc: Theodore Ts'o 
Cc: Serge Hallyn 
Cc: "Eric W. Biederman" 
Cc: Dave Chinner 
Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski 
Signed-off-by: Linus Torvalds

fs: convert use of typedef ctl_table to struct ctl_table

2014-06-06T23:08:16+00:00

This typedef is unnecessary and should just be removed.

Signed-off-by: Joe Perches 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2014-04-04T22:39:39+00:00

Pull ext4 updates from Ted Ts'o:
 "Major changes for 3.14 include support for the newly added ZERO_RANGE
  and COLLAPSE_RANGE fallocate operations, and scalability improvements
  in the jbd2 layer and in xattr handling when the extended attributes
  spill over into an external block.

  Other than that, the usual clean ups and minor bug fixes"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (42 commits)
  ext4: fix premature freeing of partial clusters split across leaf blocks
  ext4: remove unneeded test of ret variable
  ext4: fix comment typo
  ext4: make ext4_block_zero_page_range static
  ext4: atomically set inode->i_flags in ext4_set_inode_flags()
  ext4: optimize Hurd tests when reading/writing inodes
  ext4: kill i_version support for Hurd-castrated file systems
  ext4: each filesystem creates and uses its own mb_cache
  fs/mbcache.c: doucple the locking of local from global data
  fs/mbcache.c: change block and index hash chain to hlist_bl_node
  ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate
  ext4: refactor ext4_fallocate code
  ext4: Update inode i_size after the preallocation
  ext4: fix partial cluster handling for bigalloc file systems
  ext4: delete path dealloc code in ext4_ext_handle_uninitialized_extents
  ext4: only call sync_filesystm() when remounting read-only
  fs: push sync_filesystem() down to the file system's remount_fs()
  jbd2: improve error messages for inconsistent journal heads
  jbd2: minimize region locked by j_list_lock in jbd2_journal_forget()
  jbd2: minimize region locked by j_list_lock in journal_get_create_access()
  ...

Merge branch 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

2014-04-04T21:03:05+00:00

Pull renameat2 system call from Miklos Szeredi:
 "This adds a new syscall, renameat2(), which is the same as renameat()
  but with a flags argument.

  The purpose of extending rename is to add cross-rename, a symmetric
  variant of rename, which exchanges the two files.  This allows
  interesting things, which were not possible before, for example
  atomically replacing a directory tree with a symlink, etc...  This
  also allows overlayfs and friends to operate on whiteouts atomically.

  Andy Lutomirski also suggested a "noreplace" flag, which disables the
  overwriting behavior of rename.

  These two flags, RENAME_EXCHANGE and RENAME_NOREPLACE are only
  implemented for ext4 as an example and for testing"

* 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ext4: add cross rename support
  ext4: rename: split out helper functions
  ext4: rename: move EMLINK check up
  ext4: rename: create ext4_renament structure for local vars
  vfs: add cross-rename
  vfs: lock_two_nondirectories: allow directory args
  security: add flags to rename hooks
  vfs: add RENAME_NOREPLACE flag
  vfs: add renameat2 syscall
  vfs: rename: use common code for dir and non-dir
  vfs: rename: move d_move() up
  vfs: add d_is_dir()

mm + fs: store shadow entries in page cache

2014-04-03T23:21:01+00:00

Reclaim will be leaving shadow entries in the page cache radix tree upon
evicting the real page.  As those pages are found from the LRU, an
iput() can lead to the inode being freed concurrently.  At this point,
reclaim must no longer install shadow pages because the inode freeing
code needs to ensure the page tree is really empty.

Add an address_space flag, AS_EXITING, that the inode freeing code sets
under the tree lock before doing the final truncate.  Reclaim will check
for this flag before installing shadow pages.

Signed-off-by: Johannes Weiner 
Reviewed-by: Rik van Riel 
Reviewed-by: Minchan Kim 
Cc: Andrea Arcangeli 
Cc: Bob Liu 
Cc: Christoph Hellwig 
Cc: Dave Chinner 
Cc: Greg Thelen 
Cc: Hugh Dickins 
Cc: Jan Kara 
Cc: KOSAKI Motohiro 
Cc: Luigi Semenzato 
Cc: Mel Gorman 
Cc: Metin Doslu 
Cc: Michel Lespinasse 
Cc: Ozgun Erdogan 
Cc: Peter Zijlstra 
Cc: Roman Gushchin 
Cc: Ryan Mallon 
Cc: Tejun Heo 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

vfs: lock_two_nondirectories: allow directory args

2014-04-01T15:08:43+00:00

lock_two_nondirectories warned if either of its args was a directory.
Instead just ignore the directory args.  This is needed for locking in
cross rename.

Signed-off-by: J. Bruce Fields 
Signed-off-by: Miklos Szeredi