commit 2c2a7552dd6465e8fde6bc9cccf8d66ed1c1eb72 upstream.

In crypt_scatterlist, if the crypt_stat argument is not set up
correctly, the kernel crashes. Instead, by returning an error code
upstream, the error is handled safely.

The issue is detected via a static analysis tool written by us.

Fixes: 237fead619984 (ecryptfs: fs/Makefile and fs/Kconfig)
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Tyler Hicks <code@tyhicks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b4a81b87a4cfe2bb26a4a943b748d96a43ef20e8 upstream.

In ecryptfs_init_messaging(), if the allocation for 'ecryptfs_msg_ctx_arr'
fails, the previously allocated 'ecryptfs_daemon_hash' is not deallocated,
leading to a memory leak bug. To fix this issue, free
'ecryptfs_daemon_hash' before returning the error.

Cc: stable@vger.kernel.org
Fixes: 88b4a07e6610 ("[PATCH] eCryptfs: Public key transport mechanism")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit fe2e082f5da5b4a0a92ae32978f81507ef37ec66 upstream.

In parse_tag_1_packet(), if tag 1 packet contains a key larger than
ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES, no cleanup is executed, leading to a
memory leak on the allocated 'auth_tok_list_item'. To fix this issue, go to
the label 'out_free' to perform the cleanup work.

Cc: stable@vger.kernel.org
Fixes: dddfa461fc89 ("[PATCH] eCryptfs: Public key; packet management")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We need to get the underlying dentry of parent; sure, absent the races
it is the parent of underlying dentry, but there's nothing to prevent
losing a timeslice to preemtion in the middle of evaluation of
lower_dentry->d_parent->d_inode, having another process move lower_dentry
around and have its (ex)parent not pinned anymore and freed on memory
pressure.  Then we regain CPU and try to fetch ->d_inode from memory
that is freed by that point.

dentry->d_parent *is* stable here - it's an argument of ->lookup() and
we are guaranteed that it won't be moved anywhere until we feed it
to d_add/d_splice_alias.  So we safely go that way to get to its
underlying dentry.

Cc: stable@vger.kernel.org # since 2009 or so
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

lower_dentry can't go from positive to negative (we have it pinned),
but it *can* go from negative to positive.  So fetching ->d_inode
into a local variable, doing a blocking allocation, checking that
now ->d_inode is non-NULL and feeding the value we'd fetched
earlier to a function that won't accept NULL is not a good idea.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

A problem similar to the one caught in commit 74dd7c97ea2a ("ecryptfs_rename():
verify that lower dentries are still OK after lock_rename()") exists for
unlink/rmdir as well.

Instead of playing with dget_parent() of underlying dentry of victim
and hoping it's the same as underlying dentry of our directory,
do the following:
        * find the underlying dentry of victim
        * find the underlying directory of victim's parent (stable
since the victim is ecryptfs dentry and inode of its parent is
held exclusive by the caller).
        * lock the inode of dentry underlying the victim's parent
        * check that underlying dentry of victim is still hashed and
has the right parent - it can be moved, but it can't be moved to/from
the directory we are holding exclusive.  So while ->d_parent itself
might not be stable, the result of comparison is.

If the check passes, everything is fine - underlying directory is locked,
underlying victim is still a child of that directory and we can go ahead
and feed them to vfs_unlink().  As in the current mainline we need to
pin the underlying dentry of victim, so that it wouldn't go negative under
us, but that's the only temporary reference that needs to be grabbed there.
Underlying dentry of parent won't go away (it's pinned by the parent,
which is held by caller), so there's no need to grab it.

The same problem (with the same solution) exists for rmdir.  Moreover,
rename gets simpler and more robust with the same "don't bother with
dget_parent()" approach.

Fixes: 74dd7c97ea2 "ecryptfs_rename(): verify that lower dentries are still OK after lock_rename()"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull eCryptfs updates from Tyler Hicks:

 - Fix error handling when ecryptfs_read_lower() encounters an error

 - Fix read-only file creation when the eCryptfs mount is configured to
   store metadata in xattrs

 - Minor code cleanups

* tag 'ecryptfs-5.3-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  ecryptfs: Change return type of ecryptfs_process_flags
  ecryptfs: Make ecryptfs_xattr_handler static
  ecryptfs: remove unnessesary null check in ecryptfs_keyring_auth_tok_for_sig
  ecryptfs: use print_hex_dump_bytes for hexdump
  eCryptfs: fix permission denied with ecryptfs_xattr mount option when create readonly file
  ecryptfs: re-order a condition for static checkers
  eCryptfs: fix a couple type promotion bugs

This reverts merge 0f75ef6a9cff49ff612f7ce0578bced9d0b38325 (and thus
effectively commits

   7a1ade847596 ("keys: Provide KEYCTL_GRANT_PERMISSION")
   2e12256b9a76 ("keys: Replace uid/gid/perm permissions checking with an ACL")

that the merge brought in).

It turns out that it breaks booting with an encrypted volume, and Eric
biggers reports that it also breaks the fscrypt tests [1] and loading of
in-kernel X.509 certificates [2].

The root cause of all the breakage is likely the same, but David Howells
is off email so rather than try to work it out it's getting reverted in
order to not impact the rest of the merge window.

 [1] https://lore.kernel.org/lkml/20190710011559.GA7973@sol.localdomain/
 [2] https://lore.kernel.org/lkml/20190710013225.GB7973@sol.localdomain/

Link: https://lore.kernel.org/lkml/CAHk-=wjxoeMJfeBahnWH=9zShKp2bsVy527vo3_y8HfOdhwAAw@mail.gmail.com/
Reported-by: Eric Biggers <ebiggers@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull keyring ACL support from David Howells:
 "This changes the permissions model used by keys and keyrings to be
  based on an internal ACL by the following means:

   - Replace the permissions mask internally with an ACL that contains a
     list of ACEs, each with a specific subject with a permissions mask.
     Potted default ACLs are available for new keys and keyrings.

     ACE subjects can be macroised to indicate the UID and GID specified
     on the key (which remain). Future commits will be able to add
     additional subject types, such as specific UIDs or domain
     tags/namespaces.

     Also split a number of permissions to give finer control. Examples
     include splitting the revocation permit from the change-attributes
     permit, thereby allowing someone to be granted permission to revoke
     a key without allowing them to change the owner; also the ability
     to join a keyring is split from the ability to link to it, thereby
     stopping a process accessing a keyring by joining it and thus
     acquiring use of possessor permits.

   - Provide a keyctl to allow the granting or denial of one or more
     permits to a specific subject. Direct access to the ACL is not
     granted, and the ACL cannot be viewed"

* tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  keys: Provide KEYCTL_GRANT_PERMISSION
  keys: Replace uid/gid/perm permissions checking with an ACL

Change return type of ecryptfs_process_flags from int to void as it
never fails.

fixes below issue reported by coccicheck

s/ecryptfs/crypto.c:870:5-7: Unneeded variable: "rc". Return "0" on line
883

Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
[tyhicks: Remove the return value line from the function documentation]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>