Add a function for filesystems to call to implement the
FS_IOC_MEASURE_VERITY ioctl. This ioctl retrieves the file measurement
that fs-verity calculated for the given file and is enforcing for reads;
i.e., reads that don't match this hash will fail. This ioctl can be
used for authentication or logging of file measurements in userspace.
See the "FS_IOC_MEASURE_VERITY" section of
Documentation/filesystems/fsverity.rst for the documentation.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Add a function for filesystems to call to implement the
FS_IOC_ENABLE_VERITY ioctl. This ioctl enables fs-verity on a file.
See the "FS_IOC_ENABLE_VERITY" section of
Documentation/filesystems/fsverity.rst for the documentation.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
When CONFIG_UAPI_HEADER_TEST=y, exported headers are compile-tested to make
sure they can be included from user-space.
Currently, scsi_bsg_fc.h, scsi_netlink.h, and scsi_netlink_fc.h are
excluded from the test coverage. To make them join the compile-test, we
need to fix the build errors attached below.
For a case like this, we decided to use __u{8,16,32,64} variable types in
this discussion:
https://lkml.org/lkml/2019/6/5/18
Build log:
CC usr/include/scsi/scsi_netlink_fc.h.s
CC usr/include/scsi/scsi_netlink.h.s
CC usr/include/scsi/scsi_bsg_fc.h.s
In file included from ./usr/include/scsi/scsi_netlink_fc.h:10:0,
from <command-line>:32:
./usr/include/scsi/scsi_netlink.h:29:2: error: unknown type name uint8_t
uint8_t version;
^~~~~~~
./usr/include/scsi/scsi_netlink.h:30:2: error: unknown type name uint8_t
uint8_t transport;
^~~~~~~
./usr/include/scsi/scsi_netlink.h:31:2: error: unknown type name uint16_t
uint16_t magic;
^~~~~~~~
./usr/include/scsi/scsi_netlink.h:32:2: error: unknown type name uint16_t
uint16_t msgtype;
^~~~~~~~
CC usr/include/rdma/vmw_pvrdma-abi.h.s
./usr/include/scsi/scsi_netlink.h:33:2: error: unknown type name uint16_t
uint16_t msglen;
^~~~~~~~
./usr/include/scsi/scsi_netlink.h:34:33: error: uint64_t undeclared here (not in a function); did you mean __uint128_t ?
} __attribute__((aligned(sizeof(uint64_t))));
^~~~~~~~
__uint128_t
./usr/include/scsi/scsi_netlink.h:78:2: error: expected specifier-qualifier-list before uint64_t
uint64_t vendor_id;
^~~~~~~~
In file included from <command-line>:32:0:
./usr/include/scsi/scsi_netlink_fc.h:46:2: error: expected specifier-qualifier-list before uint64_t
uint64_t seconds;
^~~~~~~~
make[2]: *** [scripts/Makefile.build;302: usr/include/scsi/scsi_netlink_fc.h.s] Error 1
make[2]: *** Waiting for unfinished jobs....
In file included from <command-line>:32:0:
./usr/include/scsi/scsi_netlink.h:29:2: error: unknown type name uint8_t
uint8_t version;
^~~~~~~
./usr/include/scsi/scsi_netlink.h:30:2: error: unknown type name uint8_t
uint8_t transport;
^~~~~~~
./usr/include/scsi/scsi_netlink.h:31:2: error: unknown type name uint16_t
uint16_t magic;
^~~~~~~~
./usr/include/scsi/scsi_netlink.h:32:2: error: unknown type name uint16_t
uint16_t msgtype;
^~~~~~~~
./usr/include/scsi/scsi_netlink.h:33:2: error: unknown type name uint16_t
uint16_t msglen;
^~~~~~~~
./usr/include/scsi/scsi_netlink.h:34:33: error: uint64_t undeclared here (not in a function); did you mean __uint128_t ?
} __attribute__((aligned(sizeof(uint64_t))));
^~~~~~~~
__uint128_t
./usr/include/scsi/scsi_netlink.h:78:2: error: expected specifier-qualifier-list before uint64_t
uint64_t vendor_id;
^~~~~~~~
make[2]: *** [scripts/Makefile.build;302: usr/include/scsi/scsi_netlink.h.s] Error 1
In file included from <command-line>:32:0:
./usr/include/scsi/scsi_bsg_fc.h:69:2: error: unknown type name uint8_t
uint8_t reserved;
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:72:2: error: unknown type name uint8_t
uint8_t port_id[3];
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:90:2: error: unknown type name uint8_t
uint8_t reserved;
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:93:2: error: unknown type name uint8_t
uint8_t port_id[3];
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:114:2: error: unknown type name uint8_t
uint8_t command_code;
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:117:2: error: unknown type name uint8_t
uint8_t port_id[3];
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:154:2: error: unknown type name uint32_t
uint32_t status; /* See FC_CTELS_STATUS_xxx */
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:158:3: error: unknown type name uint8_t
uint8_t action; /* fragment_id for CT REJECT */
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:159:3: error: unknown type name uint8_t
uint8_t reason_code;
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:160:3: error: unknown type name uint8_t
uint8_t reason_explanation;
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:161:3: error: unknown type name uint8_t
uint8_t vendor_unique;
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:177:2: error: unknown type name uint8_t
uint8_t reserved;
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:180:2: error: unknown type name uint8_t
uint8_t port_id[3];
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:185:2: error: unknown type name uint32_t
uint32_t preamble_word0; /* revision & IN_ID */
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:186:2: error: unknown type name uint32_t
uint32_t preamble_word1; /* GS_Type, GS_SubType, Options, Rsvd */
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:187:2: error: unknown type name uint32_t
uint32_t preamble_word2; /* Cmd Code, Max Size */
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:207:2: error: unknown type name uint64_t
uint64_t vendor_id;
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:210:2: error: unknown type name uint32_t
uint32_t vendor_cmd[0];
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:217:2: error: unknown type name uint32_t
uint32_t vendor_rsp[0];
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:236:2: error: unknown type name uint8_t
uint8_t els_code;
^~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:254:2: error: unknown type name uint32_t
uint32_t preamble_word0; /* revision & IN_ID */
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:255:2: error: unknown type name uint32_t
uint32_t preamble_word1; /* GS_Type, GS_SubType, Options, Rsvd */
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:256:2: error: unknown type name uint32_t
uint32_t preamble_word2; /* Cmd Code, Max Size */
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:268:2: error: unknown type name uint32_t
uint32_t msgcode;
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:292:2: error: unknown type name uint32_t
uint32_t result;
^~~~~~~~
./usr/include/scsi/scsi_bsg_fc.h:295:2: error: unknown type name uint32_t
uint32_t reply_payload_rcv_len;
^~~~~~~~
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Update the fscrypt documentation file to catch up to all the latest
changes, including the new ioctls to manage master encryption keys in
the filesystem-level keyring and the support for v2 encryption policies.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Wire up the new ioctls for adding and removing fscrypt keys to/from the
filesystem, and the new ioctl for retrieving v2 encryption policies.
The key removal ioctls also required making UBIFS use
fscrypt_drop_inode().
For more details see Documentation/filesystems/fscrypt.rst and the
fscrypt patches that added the implementation of these ioctls.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Wire up the new ioctls for adding and removing fscrypt keys to/from the
filesystem, and the new ioctl for retrieving v2 encryption policies.
The key removal ioctls also required making f2fs_drop_inode() call
fscrypt_drop_inode().
For more details see Documentation/filesystems/fscrypt.rst and the
fscrypt patches that added the implementation of these ioctls.
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Wire up the new ioctls for adding and removing fscrypt keys to/from the
filesystem, and the new ioctl for retrieving v2 encryption policies.
The key removal ioctls also required making ext4_drop_inode() call
fscrypt_drop_inode().
For more details see Documentation/filesystems/fscrypt.rst and the
fscrypt patches that added the implementation of these ioctls.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
By looking up the master keys in a filesystem-level keyring rather than
in the calling processes' key hierarchy, it becomes possible for a user
to set an encryption policy which refers to some key they don't actually
know, then encrypt their files using that key. Cryptographically this
isn't much of a problem, but the semantics of this would be a bit weird.
Thus, enforce that a v2 encryption policy can only be set if the user
has previously added the key, or has capable(CAP_FOWNER).
We tolerate that this problem will continue to exist for v1 encryption
policies, however; there is no way around that.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Add a root-only variant of the FS_IOC_REMOVE_ENCRYPTION_KEY ioctl which
removes all users' claims of the key, not just the current user's claim.
I.e., it always removes the key itself, no matter how many users have
added it.
This is useful for forcing a directory to be locked, without having to
figure out which user ID(s) the key was added under. This is planned to
be used by a command like 'sudo fscrypt lock DIR --all-users' in the
fscrypt userspace tool (http://github.com/google/fscrypt).
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Allow the FS_IOC_ADD_ENCRYPTION_KEY and FS_IOC_REMOVE_ENCRYPTION_KEY
ioctls to be used by non-root users to add and remove encryption keys
from the filesystem-level crypto keyrings, subject to limitations.
Motivation: while privileged fscrypt key management is sufficient for
some users (e.g. Android and Chromium OS, where a privileged process
manages all keys), the old API by design also allows non-root users to
set up and use encrypted directories, and we don't want to regress on
that. Especially, we don't want to force users to continue using the
old API, running into the visibility mismatch between files and keyrings
and being unable to "lock" encrypted directories.
Intuitively, the ioctls have to be privileged since they manipulate
filesystem-level state. However, it's actually safe to make them
unprivileged if we very carefully enforce some specific limitations.
First, each key must be identified by a cryptographic hash so that a
user can't add the wrong key for another user's files. For v2
encryption policies, we use the key_identifier for this. v1 policies
don't have this, so managing keys for them remains privileged.
Second, each key a user adds is charged to their quota for the keyrings
service. Thus, a user can't exhaust memory by adding a huge number of
keys. By default each non-root user is allowed up to 200 keys; this can
be changed using the existing sysctl 'kernel.keys.maxkeys'.
Third, if multiple users add the same key, we keep track of those users
of the key (of which there remains a single copy), and won't really
remove the key, i.e. "lock" the encrypted files, until all those users
have removed it. This prevents denial of service attacks that would be
possible under simpler schemes, such allowing the first user who added a
key to remove it -- since that could be a malicious user who has
compromised the key. Of course, encryption keys should be kept secret,
but the idea is that using encryption should never be *less* secure than
not using encryption, even if your key was compromised.
We tolerate that a user will be unable to really remove a key, i.e.
unable to "lock" their encrypted files, if another user has added the
same key. But in a sense, this is actually a good thing because it will
avoid providing a false notion of security where a key appears to have
been removed when actually it's still in memory, available to any
attacker who compromises the operating system kernel.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Add a new fscrypt policy version, "v2". It has the following changes
from the original policy version, which we call "v1" (*):
- Master keys (the user-provided encryption keys) are only ever used as
input to HKDF-SHA512. This is more flexible and less error-prone, and
it avoids the quirks and limitations of the AES-128-ECB based KDF.
Three classes of cryptographically isolated subkeys are defined:
- Per-file keys, like used in v1 policies except for the new KDF.
- Per-mode keys. These implement the semantics of the DIRECT_KEY
flag, which for v1 policies made the master key be used directly.
These are also planned to be used for inline encryption when
support for it is added.
- Key identifiers (see below).
- Each master key is identified by a 16-byte master_key_identifier,
which is derived from the key itself using HKDF-SHA512. This prevents
users from associating the wrong key with an encrypted file or
directory. This was easily possible with v1 policies, which
identified the key by an arbitrary 8-byte master_key_descriptor.
- The key must be provided in the filesystem-level keyring, not in a
process-subscribed keyring.
The following UAPI additions are made:
- The existing ioctl FS_IOC_SET_ENCRYPTION_POLICY can now be passed a
fscrypt_policy_v2 to set a v2 encryption policy. It's disambiguated
from fscrypt_policy/fscrypt_policy_v1 by the version code prefix.
- A new ioctl FS_IOC_GET_ENCRYPTION_POLICY_EX is added. It allows
getting the v1 or v2 encryption policy of an encrypted file or
directory. The existing FS_IOC_GET_ENCRYPTION_POLICY ioctl could not
be used because it did not have a way for userspace to indicate which
policy structure is expected. The new ioctl includes a size field, so
it is extensible to future fscrypt policy versions.
- The ioctls FS_IOC_ADD_ENCRYPTION_KEY, FS_IOC_REMOVE_ENCRYPTION_KEY,
and FS_IOC_GET_ENCRYPTION_KEY_STATUS now support managing keys for v2
encryption policies. Such keys are kept logically separate from keys
for v1 encryption policies, and are identified by 'identifier' rather
than by 'descriptor'. The 'identifier' need not be provided when
adding a key, since the kernel will calculate it anyway.
This patch temporarily keeps adding/removing v2 policy keys behind the
same permission check done for adding/removing v1 policy keys:
capable(CAP_SYS_ADMIN). However, the next patch will carefully take
advantage of the cryptographically secure master_key_identifier to allow
non-root users to add/remove v2 policy keys, thus providing a full
replacement for v1 policies.
(*) Actually, in the API fscrypt_policy::version is 0 while on-disk
fscrypt_context::format is 1. But I believe it makes the most sense
to advance both to '2' to have them be in sync, and to consider the
numbering to start at 1 except for the API quirk.
Reviewed-by: Paul Crowley <paulcrowley@google.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Add an implementation of HKDF (RFC 5869) to fscrypt, for the purpose of
deriving additional key material from the fscrypt master keys for v2
encryption policies. HKDF is a key derivation function built on top of
HMAC. We choose SHA-512 for the underlying unkeyed hash, and use an
"hmac(sha512)" transform allocated from the crypto API.
We'll be using this to replace the AES-ECB based KDF currently used to
derive the per-file encryption keys. While the AES-ECB based KDF is
believed to meet the original security requirements, it is nonstandard
and has problems that don't exist in modern KDFs such as HKDF:
1. It's reversible. Given a derived key and nonce, an attacker can
easily compute the master key. This is okay if the master key and
derived keys are equally hard to compromise, but now we'd like to be
more robust against threats such as a derived key being compromised
through a timing attack, or a derived key for an in-use file being
compromised after the master key has already been removed.
2. It doesn't evenly distribute the entropy from the master key; each 16
input bytes only affects the corresponding 16 output bytes.
3. It isn't easily extensible to deriving other values or keys, such as
a public hash for securely identifying the key, or per-mode keys.
Per-mode keys will be immediately useful for Adiantum encryption, for
which fscrypt currently uses the master key directly, introducing
unnecessary usage constraints. Per-mode keys will also be useful for
hardware inline encryption, which is currently being worked on.
HKDF solves all the above problems.
Reviewed-by: Paul Crowley <paulcrowley@google.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Add a new fscrypt ioctl, FS_IOC_GET_ENCRYPTION_KEY_STATUS. Given a key
specified by 'struct fscrypt_key_specifier' (the same way a key is
specified for the other fscrypt key management ioctls), it returns
status information in a 'struct fscrypt_get_key_status_arg'.
The main motivation for this is that applications need to be able to
check whether an encrypted directory is "unlocked" or not, so that they
can add the key if it is not, and avoid adding the key (which may
involve prompting the user for a passphrase) if it already is.
It's possible to use some workarounds such as checking whether opening a
regular file fails with ENOKEY, or checking whether the filenames "look
like gibberish" or not. However, no workaround is usable in all cases.
Like the other key management ioctls, the keyrings syscalls may seem at
first to be a good fit for this. Unfortunately, they are not. Even if
we exposed the keyring ID of the ->s_master_keys keyring and gave
everyone Search permission on it (note: currently the keyrings
permission system would also allow everyone to "invalidate" the keyring
too), the fscrypt keys have an additional state that doesn't map cleanly
to the keyrings API: the secret can be removed, but we can be still
tracking the files that were using the key, and the removal can be
re-attempted or the secret added again.
After later patches, some applications will also need a way to determine
whether a key was added by the current user vs. by some other user.
Reserved fields are included in fscrypt_get_key_status_arg for this and
other future extensions.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Add a new fscrypt ioctl, FS_IOC_REMOVE_ENCRYPTION_KEY. This ioctl
removes an encryption key that was added by FS_IOC_ADD_ENCRYPTION_KEY.
It wipes the secret key itself, then "locks" the encrypted files and
directories that had been unlocked using that key -- implemented by
evicting the relevant dentries and inodes from the VFS caches.
The problem this solves is that many fscrypt users want the ability to
remove encryption keys, causing the corresponding encrypted directories
to appear "locked" (presented in ciphertext form) again. Moreover,
users want removing an encryption key to *really* remove it, in the
sense that the removed keys cannot be recovered even if kernel memory is
compromised, e.g. by the exploit of a kernel security vulnerability or
by a physical attack. This is desirable after a user logs out of the
system, for example. In many cases users even already assume this to be
the case and are surprised to hear when it's not.
It is not sufficient to simply unlink the master key from the keyring
(or to revoke or invalidate it), since the actual encryption transform
objects are still pinned in memory by their inodes. Therefore, to
really remove a key we must also evict the relevant inodes.
Currently one workaround is to run 'sync && echo 2 >
/proc/sys/vm/drop_caches'. But, that evicts all unused inodes in the
system rather than just the inodes associated with the key being
removed, causing severe performance problems. Moreover, it requires
root privileges, so regular users can't "lock" their encrypted files.
Another workaround, used in Chromium OS kernels, is to add a new
VFS-level ioctl FS_IOC_DROP_CACHE which is a more restricted version of
drop_caches that operates on a single super_block. It does:
shrink_dcache_sb(sb);
invalidate_inodes(sb, false);
But it's still a hack. Yet, the major users of filesystem encryption
want this feature badly enough that they are actually using these hacks.
To properly solve the problem, start maintaining a list of the inodes
which have been "unlocked" using each master key. Originally this
wasn't possible because the kernel didn't keep track of in-use master
keys at all. But, with the ->s_master_keys keyring it is now possible.
Then, add an ioctl FS_IOC_REMOVE_ENCRYPTION_KEY. It finds the specified
master key in ->s_master_keys, then wipes the secret key itself, which
prevents any additional inodes from being unlocked with the key. Then,
it syncs the filesystem and evicts the inodes in the key's list. The
normal inode eviction code will free and wipe the per-file keys (in
->i_crypt_info). Note that freeing ->i_crypt_info without evicting the
inodes was also considered, but would have been racy.
Some inodes may still be in use when a master key is removed, and we
can't simply revoke random file descriptors, mmap's, etc. Thus, the
ioctl simply skips in-use inodes, and returns -EBUSY to indicate that
some inodes weren't evicted. The master key *secret* is still removed,
but the fscrypt_master_key struct remains to keep track of the remaining
inodes. Userspace can then retry the ioctl to evict the remaining
inodes. Alternatively, if userspace adds the key again, the refreshed
secret will be associated with the existing list of inodes so they
remain correctly tracked for future key removals.
The ioctl doesn't wipe pagecache pages. Thus, we tolerate that after a
kernel compromise some portions of plaintext file contents may still be
recoverable from memory. This can be solved by enabling page poisoning
system-wide, which security conscious users may choose to do. But it's
very difficult to solve otherwise, e.g. note that plaintext file
contents may have been read in other places than pagecache pages.
Like FS_IOC_ADD_ENCRYPTION_KEY, FS_IOC_REMOVE_ENCRYPTION_KEY is
initially restricted to privileged users only. This is sufficient for
some use cases, but not all. A later patch will relax this restriction,
but it will require introducing key hashes, among other changes.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Add a new fscrypt ioctl, FS_IOC_ADD_ENCRYPTION_KEY. This ioctl adds an
encryption key to the filesystem's fscrypt keyring ->s_master_keys,
making any files encrypted with that key appear "unlocked".
Why we need this
~~~~~~~~~~~~~~~~
The main problem is that the "locked/unlocked" (ciphertext/plaintext)
status of encrypted files is global, but the fscrypt keys are not.
fscrypt only looks for keys in the keyring(s) the process accessing the
filesystem is subscribed to: the thread keyring, process keyring, and
session keyring, where the session keyring may contain the user keyring.
Therefore, userspace has to put fscrypt keys in the keyrings for
individual users or sessions. But this means that when a process with a
different keyring tries to access encrypted files, whether they appear
"unlocked" or not is nondeterministic. This is because it depends on
whether the files are currently present in the inode cache.
Fixing this by consistently providing each process its own view of the
filesystem depending on whether it has the key or not isn't feasible due
to how the VFS caches work. Furthermore, while sometimes users expect
this behavior, it is misguided for two reasons. First, it would be an
OS-level access control mechanism largely redundant with existing access
control mechanisms such as UNIX file permissions, ACLs, LSMs, etc.
Encryption is actually for protecting the data at rest.
Second, almost all users of fscrypt actually do need the keys to be
global. The largest users of fscrypt, Android and Chromium OS, achieve
this by having PID 1 create a "session keyring" that is inherited by
every process. This works, but it isn't scalable because it prevents
session keyrings from being used for any other purpose.
On general-purpose Linux distros, the 'fscrypt' userspace tool [1] can't
similarly abuse the session keyring, so to make 'sudo' work on all
systems it has to link all the user keyrings into root's user keyring
[2]. This is ugly and raises security concerns. Moreover it can't make
the keys available to system services, such as sshd trying to access the
user's '~/.ssh' directory (see [3], [4]) or NetworkManager trying to
read certificates from the user's home directory (see [5]); or to Docker
containers (see [6], [7]).
By having an API to add a key to the *filesystem* we'll be able to fix
the above bugs, remove userspace workarounds, and clearly express the
intended semantics: the locked/unlocked status of an encrypted directory
is global, and encryption is orthogonal to OS-level access control.
Why not use the add_key() syscall
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We use an ioctl for this API rather than the existing add_key() system
call because the ioctl gives us the flexibility needed to implement
fscrypt-specific semantics that will be introduced in later patches:
- Supporting key removal with the semantics such that the secret is
removed immediately and any unused inodes using the key are evicted;
also, the eviction of any in-use inodes can be retried.
- Calculating a key-dependent cryptographic identifier and returning it
to userspace.
- Allowing keys to be added and removed by non-root users, but only keys
for v2 encryption policies; and to prevent denial-of-service attacks,
users can only remove keys they themselves have added, and a key is
only really removed after all users who added it have removed it.
Trying to shoehorn these semantics into the keyrings syscalls would be
very difficult, whereas the ioctls make things much easier.
However, to reuse code the implementation still uses the keyrings
service internally. Thus we get lockless RCU-mode key lookups without
having to re-implement it, and the keys automatically show up in
/proc/keys for debugging purposes.
References:
[1] https://github.com/google/fscrypt
[2] https://goo.gl/55cCrI#heading=h.vf09isp98isb
[3] https://github.com/google/fscrypt/issues/111#issuecomment-444347939
[4] https://github.com/google/fscrypt/issues/116
[5] https://bugs.launchpad.net/ubuntu/+source/fscrypt/+bug/1770715
[6] https://github.com/google/fscrypt/issues/128
[7] https://askubuntu.com/questions/1130306/cannot-run-docker-on-an-encrypted-filesystem
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Rename keyinfo.c to keysetup.c since this better describes what the file
does (sets up the key), and it matches the new file keysetup_v1.c.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
In preparation for introducing v2 encryption policies which will find
and derive encryption keys differently from the current v1 encryption
policies, move the v1 policy-specific key setup code from keyinfo.c into
keysetup_v1.c.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Do some more refactoring of the key setup code, in preparation for
introducing a filesystem-level keyring and v2 encryption policies:
- Now that ci_inode exists, don't pass around the inode unnecessarily.
- Define a function setup_file_encryption_key() which handles the crypto
key setup given an under-construction fscrypt_info. Don't pass the
fscrypt_context, since everything is in the fscrypt_info.
[This will be extended for v2 policies and the fs-level keyring.]
- Define a function fscrypt_set_derived_key() which sets the per-file
key, without depending on anything specific to v1 policies.
[This will also be used for v2 policies.]
- Define a function fscrypt_setup_v1_file_key() which takes the raw
master key, thus separating finding the key from using it.
[This will also be used if the key is found in the fs-level keyring.]
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
In preparation for introducing a filesystem-level keyring which will
contain fscrypt master keys, rename the existing 'struct
fscrypt_master_key' to 'struct fscrypt_direct_key'. This is the
structure in the existing table of master keys that's maintained to
deduplicate the crypto transforms for v1 DIRECT_KEY policies.
I've chosen to keep this table as-is rather than make it automagically
add/remove the keys to/from the filesystem-level keyring, since that
would add a lot of extra complexity to the filesystem-level keyring.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Add an inode back-pointer to 'struct fscrypt_info', such that
inode->i_crypt_info->ci_inode == inode.
This will be useful for:
1. Evicting the inodes when a fscrypt key is removed, since we'll track
the inodes using a given key by linking their fscrypt_infos together,
rather than the inodes directly. This avoids bloating 'struct inode'
with a new list_head.
2. Simplifying the per-file key setup, since the inode pointer won't
have to be passed around everywhere just in case something goes wrong
and it's needed for fscrypt_warn().
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Update fs/crypto/ to use the new names for the UAPI constants rather
than the old names, then make the old definitions conditional on
!__KERNEL__.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Prefix all filesystem encryption UAPI constants except the ioctl numbers
with "FSCRYPT_" rather than with "FS_". This namespaces the constants
more appropriately and makes it clear that they are related specifically
to the filesystem encryption feature, and to the 'fscrypt_*' structures.
With some of the old names like "FS_POLICY_FLAGS_VALID", it was not
immediately clear that the constant had anything to do with encryption.
This is also useful because we'll be adding more encryption-related
constants, e.g. for the policy version, and we'd otherwise have to
choose whether to use unclear names like FS_POLICY_V1 or inconsistent
names like FS_ENCRYPTION_POLICY_V1.
For source compatibility with existing userspace programs, keep the old
names defined as aliases to the new names.
Finally, as long as new names are being defined anyway, I skipped
defining new names for the fscrypt mode numbers that aren't actually
used: INVALID (0), AES_256_GCM (2), AES_256_CBC (3), SPECK128_256_XTS
(7), and SPECK128_256_CTS (8).
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
More fscrypt definitions are being added, and we shouldn't use a
disproportionate amount of space in <linux/fs.h> for fscrypt stuff.
So move the fscrypt definitions to a new header <linux/fscrypt.h>.
For source compatibility with existing userspace programs, <linux/fs.h>
still includes the new header.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Return ENOPKG rather than ENOENT when trying to open a file that's
encrypted using algorithms not available in the kernel's crypto API.
This avoids an ambiguity, since ENOENT is also returned when the file
doesn't exist.
Note: this is the same approach I'm taking for fs-verity.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Users of fscrypt with non-default algorithms will encounter an error
like the following if they fail to include the needed algorithms into
the crypto API when configuring the kernel (as per the documentation):
Error allocating 'adiantum(xchacha12,aes)' transform: -2
This requires that the user figure out what the "-2" error means.
Make it more friendly by printing a warning like the following instead:
Missing crypto API support for Adiantum (API name: "adiantum(xchacha12,aes)")
Also upgrade the log level for *other* errors to KERN_ERR.
Signed-off-by: Eric Biggers <ebiggers@google.com>
When fs/crypto/ encounters an inode with an invalid encryption context,
currently it prints a warning if the pair of encryption modes are
unrecognized, but it's silent if there are other problems such as
unsupported context size, format, or flags. To help people debug such
situations, add more warning messages.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Most of the warning and error messages in fs/crypto/ are for situations
related to a specific inode, not merely to a super_block. So to make
things easier, make fscrypt_msg() take an inode rather than a
super_block, and make it print the inode number.
Note: This is the same approach I'm taking for fsverity_msg().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Some minor cleanups for the code that base64 encodes and decodes
encrypted filenames and long name digests:
- Rename "digest_{encode,decode}()" => "base64_{encode,decode}()" since
they are used for filenames too, not just for long name digests.
- Replace 'while' loops with more conventional 'for' loops.
- Use 'u8' for binary data. Keep 'char' for string data.
- Fully constify the lookup table (pointer was not const).
- Improve comment.
No actual change in behavior.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Since commit 643fa9612b ("fscrypt: remove filesystem specific build
config option"), fs/crypto/ can no longer be built as a loadable module.
Thus it no longer needs a module_exit function, nor a MODULE_LICENSE.
So remove them, and change module_init to late_initcall.
Reviewed-by: Chandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Commit 8c0d3a02c1 ("PCI: Add accessors for PCI Express Capability") added
accessors for the PCI Express Capability so that drivers didn't need to be
aware of differences between v1 and v2 of the PCI Express Capability.
Replace pci_read_config_word() and pci_write_config_word() calls with
pcie_capability_read_word() and pcie_capability_write_word().
Signed-off-by: Frederick Lawler <fred@fredlawl.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Commit 8c0d3a02c1 ("PCI: Add accessors for PCI Express Capability") added
accessors for the PCI Express Capability so that drivers didn't need to be
aware of differences between v1 and v2 of the PCI Express Capability.
Replace pci_read_config_word() and pci_write_config_word() calls with
pcie_capability_read_word() and pcie_capability_write_word().
Signed-off-by: Frederick Lawler <fred@fredlawl.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Variable retv is initialized to a value that is never read and it is
re-assigned later. The initialization is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This should be 'pmcraid', not 'pcmraid'
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Mark switch cases where we are expecting to fall through.
Fix the following warnings (Building: rpc_defconfig arm):
drivers/scsi/arm/fas216.c: In function fas216_disconnect_intr :
drivers/scsi/arm/fas216.c:913:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (fas216_get_last_msg(info, info->scsi.msgin_fifo) == ABORT) {
^
drivers/scsi/arm/fas216.c:919:2: note: here
default: /* huh? */
^~~~~~~
drivers/scsi/arm/fas216.c: In function fas216_kick :
drivers/scsi/arm/fas216.c:1959:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
fas216_allocate_tag(info, SCpnt);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/arm/fas216.c:1960:2: note: here
case TYPE_OTHER:
^~~~
drivers/scsi/arm/fas216.c: In function fas216_busservice_intr :
drivers/scsi/arm/fas216.c:1413:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
fas216_stoptransfer(info);
^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/arm/fas216.c:1414:2: note: here
case STATE(STAT_STATUS, PHASE_SELSTEPS):/* Sel w/ steps -> Status */
^~~~
drivers/scsi/arm/fas216.c:1424:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
fas216_stoptransfer(info);
^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/arm/fas216.c:1425:2: note: here
case STATE(STAT_MESGIN, PHASE_COMMAND): /* Command -> Message In */
^~~~
drivers/scsi/arm/fas216.c: In function fas216_funcdone_intr :
drivers/scsi/arm/fas216.c:1573:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((stat & STAT_BUSMASK) == STAT_MESGIN) {
^
drivers/scsi/arm/fas216.c:1579:2: note: here
default:
^~~~~~~
drivers/scsi/arm/fas216.c: In function fas216_handlesync :
drivers/scsi/arm/fas216.c:605:20: warning: this statement may fall through [-Wimplicit-fallthrough=]
info->scsi.phase = PHASE_MSGOUT_EXPECT;
~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
drivers/scsi/arm/fas216.c:607:2: note: here
case async:
^~~~
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch provides a module parameter and sysfs interface to select
whether the queue depth for each device should be based on the value
suggested by firmware (the default) or the maximum supported by the
controller (can_queue).
Although we have a sysfs interface per sdev to change the queue depth of
individual scsi devices, this implementation provides a single sysfs entry
per shost to switch between the controller max and the value reported by
firmware. The module parameter can provide an interface for one time grub
settings and provides persistent settings across the boot.
[mkp: tweaked commit desc]
Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Chandrakanth Patil <chandrakanth.patil@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Make the code easier to read by converting 'goto' statements into
'return' statements.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch fixes the following Coverity complaint:
Null-checking sp->u.iocb_cmd.u.ctarg.rsp suggests that it may be null, but
it has already been dereferenced on all paths leading to the check.
See also commit e374f9f592 ("scsi: qla2xxx: Migrate switch registration commands away from mailbox interface") # v4.16.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Instead of calling qla2x00_fcport_event_handler() and letting the switch
statement inside that function decide which other function to call, call
the latter function directly. Remove the event member from the event_arg
structure because it is no longer needed. Remove the
qla_handle_els_plogi_done() function because it is never called.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
It is easy to mix up the QLA_* and the MBS_* status codes. Complain loudly
if that happens.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The C language supports implicit casting of void pointers to non-void
pointers. Remove explicit sts_entry_* casts that are not necessary.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Split srb_cmd.ctx into two pointers such that the compiler can check the
type of that pointer.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Not calling sp->done() from the command completion path is a severe bug.
Hence complain loudly if that happens.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The LIO core requires that the target driver callback functions
.queue_data_in() and .queue_status() call target_put_sess_cmd() or
transport_generic_free_cmd(). These calls may happen synchronously or
asynchronously. Make sure that one of these LIO functions is called in case
a command has been aborted. This patch avoids that the code for removing a
session hangs due to commands that do not make progress.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Fixes: 694833ee00 ("scsi: tcm_qla2xxx: Do not allow aborted cmd to advance.") # v4.13.
Fixes: a07100e00a ("qla2xxx: Fix TMR ABORT interaction issue between qla2xxx and TCM") # v4.5.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Since struct sg_table is used in nvme-fc-driver.h, include
<linux/scatterlist.h> from that header file.
Since no definitions or declarations from <linux/blk-mq.h> are used in the
qla_nvme.h header file, do not include <linux/blk-mq.h> from that header
file.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Avoid that this function crashes if mcmd == NULL.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Instead of allocating a struct srb dynamically from inside .queuecommand(),
set qla2xxx_driver_template.cmd_size such that struct scsi_cmnd and struct
srb are contiguous. Do not call QLA_QPAIR_MARK_BUSY() /
QLA_QPAIR_MARK_NOT_BUSY() for SRBs associated with SCSI commands. That is
safe because scsi_remove_host() is called before queue pairs are deleted
and scsi_remove_host() waits for all outstanding SCSI commands to finish.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch does not change any functionality but makes the next patch
easier to read.
Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
