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2019-01-06fscrypt: add Adiantum supportEric Biggers5-110/+363
Add support for the Adiantum encryption mode to fscrypt. Adiantum is a tweakable, length-preserving encryption mode with security provably reducible to that of XChaCha12 and AES-256, subject to a security bound. It's also a true wide-block mode, unlike XTS. See the paper "Adiantum: length-preserving encryption for entry-level processors" (https://eprint.iacr.org/2018/720.pdf) for more details. Also see commit 059c2a4d8e16 ("crypto: adiantum - add Adiantum support"). On sufficiently long messages, Adiantum's bottlenecks are XChaCha12 and the NH hash function. These algorithms are fast even on processors without dedicated crypto instructions. Adiantum makes it feasible to enable storage encryption on low-end mobile devices that lack AES instructions; currently such devices are unencrypted. On ARM Cortex-A7, on 4096-byte messages Adiantum encryption is about 4 times faster than AES-256-XTS encryption; decryption is about 5 times faster. In fscrypt, Adiantum is suitable for encrypting both file contents and names. With filenames, it fixes a known weakness: when two filenames in a directory share a common prefix of >= 16 bytes, with CTS-CBC their encrypted filenames share a common prefix too, leaking information. Adiantum does not have this problem. Since Adiantum also accepts long tweaks (IVs), it's also safe to use the master key directly for Adiantum encryption rather than deriving per-file keys, provided that the per-file nonce is included in the IVs and the master key isn't used for any other encryption mode. This configuration saves memory and improves performance. A new fscrypt policy flag is added to allow users to opt-in to this configuration. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-09-04crypto: speck - remove SpeckJason A. Donenfeld2-14/+0
These are unused, undesired, and have never actually been used by anybody. The original authors of this code have changed their mind about its inclusion. While originally proposed for disk encryption on low-end devices, the idea was discarded [1] in favor of something else before that could really get going. Therefore, this patch removes Speck. [1] https://marc.info/?l=linux-crypto-vger&m=153359499015659 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Eric Biggers <ebiggers@google.com> Cc: stable@vger.kernel.org Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-06-11Merge tag 'f2fs-for-4.18' of ↵Linus Torvalds3-15/+29
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs Pull f2fs updates from Jaegeuk Kim: "In this round, we've mainly focused on discard, aka unmap, control along with fstrim for Android-specific usage model. In addition, we've fixed writepage flow which returned EAGAIN previously resulting in EIO of fsync(2) due to mapping's error state. In order to avoid old MM bug [1], we decided not to use __GFP_ZERO for the mapping for node and meta page caches. As always, we've cleaned up many places for future fsverity and symbol conflicts. Enhancements: - do discard/fstrim in lower priority considering fs utilization - split large discard commands into smaller ones for better responsiveness - add more sanity checks to address syzbot reports - add a mount option, fsync_mode=nobarrier, which can reduce # of cache flushes - clean up symbol namespace with modified function names - be strict on block allocation and IO control in corner cases Bug fixes: - don't use __GFP_ZERO for mappings - fix error reports in writepage to avoid fsync() failure - avoid selinux denial on CAP_RESOURCE on resgid/resuid - fix some subtle race conditions in GC/atomic writes/shutdown - fix overflow bugs in sanity_check_raw_super - fix missing bits on get_flags Clean-ups: - prepare the generic flow for future fsverity integration - fix some broken coding standard" [1] https://lkml.org/lkml/2018/4/8/661 * tag 'f2fs-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (79 commits) f2fs: fix to clear FI_VOLATILE_FILE correctly f2fs: let sync node IO interrupt async one f2fs: don't change wbc->sync_mode f2fs: fix to update mtime correctly fs: f2fs: insert space around that ':' and ', ' fs: f2fs: add missing blank lines after declarations fs: f2fs: changed variable type of offset "unsigned" to "loff_t" f2fs: clean up symbol namespace f2fs: make set_de_type() static f2fs: make __f2fs_write_data_pages() static f2fs: fix to avoid accessing cross the boundary f2fs: fix to let caller retry allocating block address disable loading f2fs module on PAGE_SIZE > 4KB f2fs: fix error path of move_data_page f2fs: don't drop dentry pages after fs shutdown f2fs: fix to avoid race during access gc_thread pointer f2fs: clean up with clear_radix_tree_dirty_tag f2fs: fix to don't trigger writeback during recovery f2fs: clear discard_wake earlier f2fs: let discard thread wait a little longer if dev is busy ...
2018-05-20fscrypt: log the crypto algorithm implementationsEric Biggers1-34/+68
Log the crypto algorithm driver name for each fscrypt encryption mode on its first use, also showing a friendly name for the mode. This will help people determine whether the expected implementations are being used. In some cases we've seen people do benchmarks and reject using encryption for performance reasons, when in fact they used a much slower implementation of AES-XTS than was possible on the hardware. It can make an enormous difference; e.g., AES-XTS on ARM is about 10x faster with the crypto extensions (AES instructions) than without. This also makes it more obvious which modes are being used, now that fscrypt supports multiple combinations of modes. Example messages (with default modes, on x86_64): [ 35.492057] fscrypt: AES-256-CTS-CBC using implementation "cts(cbc-aes-aesni)" [ 35.492171] fscrypt: AES-256-XTS using implementation "xts-aes-aesni" Note: algorithms can be dynamically added to the crypto API, which can result in different implementations being used at different times. But this is rare; for most users, showing the first will be good enough. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: add Speck128/256 supportEric Biggers2-0/+6
fscrypt currently only supports AES encryption. However, many low-end mobile devices have older CPUs that don't have AES instructions, e.g. the ARMv8 Cryptography Extensions. Currently, user data on such devices is not encrypted at rest because AES is too slow, even when the NEON bit-sliced implementation of AES is used. Unfortunately, it is infeasible to encrypt these devices at all when AES is the only option. Therefore, this patch updates fscrypt to support the Speck block cipher, which was recently added to the crypto API. The C implementation of Speck is not especially fast, but Speck can be implemented very efficiently with general-purpose vector instructions, e.g. ARM NEON. For example, on an ARMv7 processor, we measured the NEON-accelerated Speck128/256-XTS at 69 MB/s for both encryption and decryption, while AES-256-XTS with the NEON bit-sliced implementation was only 22 MB/s encryption and 19 MB/s decryption. There are multiple variants of Speck. This patch only adds support for Speck128/256, which is the variant with a 128-bit block size and 256-bit key size -- the same as AES-256. This is believed to be the most secure variant of Speck, and it's only about 6% slower than Speck128/128. Speck64/128 would be at least 20% faster because it has 20% rounds, and it can be even faster on CPUs that can't efficiently do the 64-bit operations needed for Speck128. However, Speck64's 64-bit block size is not preferred security-wise. ARM NEON also supports the needed 64-bit operations even on 32-bit CPUs, resulting in Speck128 being fast enough for our targeted use cases so far. The chosen modes of operation are XTS for contents and CTS-CBC for filenames. These are the same modes of operation that fscrypt defaults to for AES. Note that as with the other fscrypt modes, Speck will not be used unless userspace chooses to use it. Nor are any of the existing modes (which are all AES-based) being removed, of course. We intentionally don't make CONFIG_FS_ENCRYPTION select CONFIG_CRYPTO_SPECK, so people will have to enable Speck support themselves if they need it. This is because we shouldn't bloat the FS_ENCRYPTION dependencies with every new cipher, especially ones that aren't recommended for most users. Moreover, CRYPTO_SPECK is just the generic implementation, which won't be fast enough for many users; in practice, they'll need to enable CRYPTO_SPECK_NEON to get acceptable performance. More details about our choice of Speck can be found in our patches that added Speck to the crypto API, and the follow-on discussion threads. We're planning a publication that explains the choice in more detail. But briefly, we can't use ChaCha20 as we previously proposed, since it would be insecure to use a stream cipher in this context, with potential IV reuse during writes on f2fs and/or on wear-leveling flash storage. We also evaluated many other lightweight and/or ARX-based block ciphers such as Chaskey-LTS, RC5, LEA, CHAM, Threefish, RC6, NOEKEON, SPARX, and XTEA. However, all had disadvantages vs. Speck, such as insufficient performance with NEON, much less published cryptanalysis, or an insufficient security level. Various design choices in Speck make it perform better with NEON than competing ciphers while still having a security margin similar to AES, and in the case of Speck128 also the same available security levels. Unfortunately, Speck does have some political baggage attached -- it's an NSA designed cipher, and was rejected from an ISO standard (though for context, as far as I know none of the above-mentioned alternatives are ISO standards either). Nevertheless, we believe it is a good solution to the problem from a technical perspective. Certain algorithms constructed from ChaCha or the ChaCha permutation, such as MEM (Masked Even-Mansour) or HPolyC, may also meet our performance requirements. However, these are new constructions that need more time to receive the cryptographic review and acceptance needed to be confident in their security. HPolyC hasn't been published yet, and we are concerned that MEM makes stronger assumptions about the underlying permutation than the ChaCha stream cipher does. In contrast, the XTS mode of operation is relatively well accepted, and Speck has over 70 cryptanalysis papers. Of course, these ChaCha-based algorithms can still be added later if they become ready. The best known attack on Speck128/256 is a differential cryptanalysis attack on 25 of 34 rounds with 2^253 time complexity and 2^125 chosen plaintexts, i.e. only marginally faster than brute force. There is no known attack on the full 34 rounds. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: only derive the needed portion of the keyEric Biggers1-23/+16
Currently the key derivation function in fscrypt uses the master key length as the amount of output key material to derive. This works, but it means we can waste time deriving more key material than is actually used, e.g. most commonly, deriving 64 bytes for directories which only take a 32-byte AES-256-CTS-CBC key. It also forces us to validate that the master key length is a multiple of AES_BLOCK_SIZE, which wouldn't otherwise be necessary. Fix it to only derive the needed length key. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: separate key lookup from key derivationEric Biggers1-48/+74
Refactor the confusingly-named function 'validate_user_key()' into a new function 'find_and_derive_key()' which first finds the keyring key, then does the key derivation. Among other benefits this avoids the strange behavior we had previously where if key derivation failed for some reason, then we would fall back to the alternate key prefix. Now, we'll only fall back to the alternate key prefix if a valid key isn't found. This patch also improves the warning messages that are logged when the keyring key's payload is invalid. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: use a common logging functionEric Biggers5-21/+57
Use a common function for fscrypt warning and error messages so that all the messages are consistently ratelimited, include the "fscrypt:" prefix, and include the filesystem name if applicable. Also fix up a few of the log messages to be more descriptive. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: remove internal key size constantsEric Biggers2-20/+7
With one exception, the internal key size constants such as FS_AES_256_XTS_KEY_SIZE are only used for the 'available_modes' array, where they really only serve to obfuscate what the values are. Also some of the constants are unused, and the key sizes tend to be in the names of the algorithms anyway. In the past these values were also misused, e.g. we used to have FS_AES_256_XTS_KEY_SIZE in places that technically should have been FS_MAX_KEY_SIZE. The exception is that FS_AES_128_ECB_KEY_SIZE is used for key derivation. But it's more appropriate to use FS_KEY_DERIVATION_NONCE_SIZE for that instead. Thus, just put the sizes directly in the 'available_modes' array. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: remove unnecessary check for non-logon key typeEric Biggers1-6/+0
We're passing 'key_type_logon' to request_key(), so the found key is guaranteed to be of type "logon". Thus, there is no reason to check later that the key is really a "logon" key. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: make fscrypt_operations.max_namelen an integerEric Biggers1-1/+1
Now ->max_namelen() is only called to limit the filename length when adding NUL padding, and only for real filenames -- not symlink targets. It also didn't give the correct length for symlink targets anyway since it forgot to subtract 'sizeof(struct fscrypt_symlink_data)'. Thus, change ->max_namelen from a function to a simple 'unsigned int' that gives the filesystem's maximum filename length. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: drop empty name check from fname_decrypt()Eric Biggers1-3/+0
fname_decrypt() is validating that the encrypted filename is nonempty. However, earlier a stronger precondition was already enforced: the encrypted filename must be at least 16 (FS_CRYPTO_BLOCK_SIZE) bytes. Drop the redundant check for an empty filename. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: drop max_namelen check from fname_decrypt()Eric Biggers1-5/+2
fname_decrypt() returns an error if the input filename is longer than the inode's ->max_namelen() as given by the filesystem. But, this doesn't actually make sense because the filesystem provided the input filename in the first place, where it was subject to the filesystem's limits. And fname_decrypt() has no internal limit itself. Thus, remove this unnecessary check. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: don't special-case EOPNOTSUPP from fscrypt_get_encryption_info()Eric Biggers1-1/+1
In fscrypt_setup_filename(), remove the unnecessary check for fscrypt_get_encryption_info() returning EOPNOTSUPP. There's no reason to handle this error differently from any other. I think there may have been some confusion because the "notsupp" version of fscrypt_get_encryption_info() returns EOPNOTSUPP -- but that's not applicable from inside fs/crypto/. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: don't clear flags on crypto transformEric Biggers1-1/+0
fscrypt is clearing the flags on the crypto_skcipher it allocates for each inode. But, this is unnecessary and may cause problems in the future because it will even clear flags that are meant to be internal to the crypto API, e.g. CRYPTO_TFM_NEED_KEY. Remove the unnecessary flag clearing. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: remove stale comment from fscrypt_d_revalidate()Eric Biggers1-1/+0
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: remove error messages for skcipher_request_alloc() failureEric Biggers2-13/+3
skcipher_request_alloc() can only fail due to lack of memory, and in that case the memory allocator will have already printed a detailed error message. Thus, remove the redundant error messages from fscrypt. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: remove unnecessary NULL check when allocating skcipherEric Biggers1-2/+2
crypto_alloc_skcipher() returns an ERR_PTR() on failure, not NULL. Remove the unnecessary check for NULL. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: clean up after fscrypt_prepare_lookup() conversionsEric Biggers2-1/+1
Now that all filesystems have been converted to use fscrypt_prepare_lookup(), we can remove the fscrypt_set_d_op() and fscrypt_set_encrypted_dentry() functions as well as un-export fscrypt_d_ops. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-20fscrypt: use unbound workqueue for decryptionEric Biggers1-1/+10
Improve fscrypt read performance by switching the decryption workqueue from bound to unbound. With the bound workqueue, when multiple bios completed on the same CPU, they were decrypted on that same CPU. But with the unbound queue, they are now decrypted in parallel on any CPU. Although fscrypt read performance can be tough to measure due to the many sources of variation, this change is most beneficial when decryption is slow, e.g. on CPUs without AES instructions. For example, I timed tarring up encrypted directories on f2fs. On x86 with AES-NI instructions disabled, the unbound workqueue improved performance by about 25-35%, using 1 to NUM_CPUs jobs with 4 or 8 CPUs available. But with AES-NI enabled, performance was unchanged to within ~2%. I also did the same test on a quad-core ARM CPU using xts-speck128-neon encryption. There performance was usually about 10% better with the unbound workqueue, bringing it closer to the unencrypted speed. The unbound workqueue may be worse in some cases due to worse locality, but I think it's still the better default. dm-crypt uses an unbound workqueue by default too, so this change makes fscrypt match. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-03fscrypt: allow synchronous bio decryptionEric Biggers3-15/+29
Currently, fscrypt provides fscrypt_decrypt_bio_pages() which decrypts a bio's pages asynchronously, then unlocks them afterwards. But, this assumes that decryption is the last "postprocessing step" for the bio, so it's incompatible with additional postprocessing steps such as authenticity verification after decryption. Therefore, rename the existing fscrypt_decrypt_bio_pages() to fscrypt_enqueue_decrypt_bio(). Then, add fscrypt_decrypt_bio() which decrypts the pages in the bio synchronously without unlocking the pages, nor setting them Uptodate; and add fscrypt_enqueue_decrypt_work(), which enqueues work on the fscrypt_read_workqueue. The new functions will be used by filesystems that support both fscrypt and fs-verity. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-02-01fscrypt: fix build with pre-4.6 gcc versionsEric Biggers1-1/+1
gcc versions prior to 4.6 require an extra level of braces when using a designated initializer for a member in an anonymous struct or union. This caused a compile error with the 'struct qstr' initialization in __fscrypt_encrypt_symlink(). Fix it by using QSTR_INIT(). Reported-by: Andrew Morton <akpm@linux-foundation.org> Fixes: 76e81d6d5048 ("fscrypt: new helper functions for ->symlink()") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: remove 'ci' parameter from fscrypt_put_encryption_info()Eric Biggers1-13/+3
fscrypt_put_encryption_info() is only called when evicting an inode, so the 'struct fscrypt_info *ci' parameter is always NULL, and there cannot be races with other threads. This was cruft left over from the broken key revocation code. Remove the unused parameter and the cmpxchg(). Also remove the #ifdefs around the fscrypt_put_encryption_info() calls, since fscrypt_notsupp.h defines a no-op stub for it. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: fix up fscrypt_fname_encrypted_size() for internal useEric Biggers3-21/+23
Filesystems don't need fscrypt_fname_encrypted_size() anymore, so unexport it and move it to fscrypt_private.h. We also never calculate the encrypted size of a filename without having the fscrypt_info present since it is needed to know the amount of NUL-padding which is determined by the encryption policy, and also we will always truncate the NUL-padding to the maximum filename length. Therefore, also make fscrypt_fname_encrypted_size() assume that the fscrypt_info is present, and make it truncate the returned length to the specified max_len. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: define fscrypt_fname_alloc_buffer() to be for presented namesEric Biggers1-15/+14
Previously fscrypt_fname_alloc_buffer() was used to allocate buffers for both presented (decrypted or encoded) and encrypted filenames. That was confusing, because it had to allocate the worst-case size for either, e.g. including NUL-padding even when it was meaningless. But now that fscrypt_setup_filename() no longer calls it, it is only used in the ->get_link() and ->readdir() paths, which specifically want a buffer for presented filenames. Therefore, switch the behavior over to allocating the buffer for presented filenames only. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: calculate NUL-padding length in one place onlyEric Biggers3-35/+29
Currently, when encrypting a filename (either a real filename or a symlink target) we calculate the amount of NUL-padding twice: once before encryption and once during encryption in fname_encrypt(). It is needed before encryption to allocate the needed buffer size as well as calculate the size the symlink target will take up on-disk before creating the symlink inode. Calculating the size during encryption as well is redundant. Remove this redundancy by always calculating the exact size beforehand, and making fname_encrypt() just add as much NUL padding as is needed to fill the output buffer. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: move fscrypt_symlink_data to fscrypt_private.hEric Biggers1-0/+9
Now that all filesystems have been converted to use the symlink helper functions, they no longer need the declaration of 'struct fscrypt_symlink_data'. Move it from fscrypt.h to fscrypt_private.h. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: remove fscrypt_fname_usr_to_disk()Eric Biggers1-29/+0
fscrypt_fname_usr_to_disk() sounded very generic but was actually only used to encrypt symlinks. Remove it now that all filesystems have been switched over to fscrypt_encrypt_symlink(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: new helper function - fscrypt_get_symlink()Eric Biggers1-0/+73
Filesystems also have duplicate code to support ->get_link() on encrypted symlinks. Factor it out into a new function fscrypt_get_symlink(). It takes in the contents of the encrypted symlink on-disk and provides the target (decrypted or encoded) that should be returned from ->get_link(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: new helper functions for ->symlink()Eric Biggers3-3/+99
Currently, filesystems supporting fscrypt need to implement some tricky logic when creating encrypted symlinks, including handling a peculiar on-disk format (struct fscrypt_symlink_data) and correctly calculating the size of the encrypted symlink. Introduce helper functions to make things a bit easier: - fscrypt_prepare_symlink() computes and validates the size the symlink target will require on-disk. - fscrypt_encrypt_symlink() creates the encrypted target if needed. The new helpers actually fix some subtle bugs. First, when checking whether the symlink target was too long, filesystems didn't account for the fact that the NUL padding is meant to be truncated if it would cause the maximum length to be exceeded, as is done for filenames in directories. Consequently users would receive ENAMETOOLONG when creating symlinks close to what is supposed to be the maximum length. For example, with EXT4 with a 4K block size, the maximum symlink target length in an encrypted directory is supposed to be 4093 bytes (in comparison to 4095 in an unencrypted directory), but in FS_POLICY_FLAGS_PAD_32-mode only up to 4064 bytes were accepted. Second, symlink targets of "." and ".." were not being encrypted, even though they should be, as these names are special in *directory entries* but not in symlink targets. Fortunately, we can fix this simply by starting to encrypt them, as old kernels already accept them in encrypted form. Third, the output string length the filesystems were providing when doing the actual encryption was incorrect, as it was forgotten to exclude 'sizeof(struct fscrypt_symlink_data)'. Fortunately though, this bug didn't make a difference. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: trim down fscrypt.h includesEric Biggers3-0/+3
fscrypt.h included way too many other headers, given that it is included by filesystems both with and without encryption support. Trim down the includes list by moving the needed includes into more appropriate places, and removing the unneeded ones. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: move fscrypt_is_dot_dotdot() to fs/crypto/fname.cEric Biggers1-0/+11
Only fs/crypto/fname.c cares about treating the "." and ".." filenames specially with regards to encryption, so move fscrypt_is_dot_dotdot() from fscrypt.h to there. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: move fscrypt_valid_enc_modes() to fscrypt_private.hEric Biggers1-0/+14
The encryption modes are validated by fs/crypto/, not by individual filesystems. Therefore, move fscrypt_valid_enc_modes() from fscrypt.h to fscrypt_private.h. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-01-12fscrypt: move fscrypt_info_cachep declaration to fscrypt_private.hEric Biggers1-0/+1
The fscrypt_info kmem_cache is internal to fscrypt; filesystems don't need to access it. So move its declaration into fscrypt_private.h. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-11-14Merge tag 'fscrypt-for-linus' of ↵Linus Torvalds7-14/+123
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt Pull fscrypt updates from Ted Ts'o: "Lots of cleanups, mostly courtesy by Eric Biggers" * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt: fscrypt: lock mutex before checking for bounce page pool fscrypt: add a documentation file for filesystem-level encryption ext4: switch to fscrypt_prepare_setattr() ext4: switch to fscrypt_prepare_lookup() ext4: switch to fscrypt_prepare_rename() ext4: switch to fscrypt_prepare_link() ext4: switch to fscrypt_file_open() fscrypt: new helper function - fscrypt_prepare_setattr() fscrypt: new helper function - fscrypt_prepare_lookup() fscrypt: new helper function - fscrypt_prepare_rename() fscrypt: new helper function - fscrypt_prepare_link() fscrypt: new helper function - fscrypt_file_open() fscrypt: new helper function - fscrypt_require_key() fscrypt: remove unneeded empty fscrypt_operations structs fscrypt: remove ->is_encrypted() fscrypt: switch from ->is_encrypted() to IS_ENCRYPTED() fs, fscrypt: add an S_ENCRYPTED inode flag fscrypt: clean up include file mess
2017-11-14Merge branch 'linus' of ↵Linus Torvalds4-82/+13
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto updates from Herbert Xu: "Here is the crypto update for 4.15: API: - Disambiguate EBUSY when queueing crypto request by adding ENOSPC. This change touches code outside the crypto API. - Reset settings when empty string is written to rng_current. Algorithms: - Add OSCCA SM3 secure hash. Drivers: - Remove old mv_cesa driver (replaced by marvell/cesa). - Enable rfc3686/ecb/cfb/ofb AES in crypto4xx. - Add ccm/gcm AES in crypto4xx. - Add support for BCM7278 in iproc-rng200. - Add hash support on Exynos in s5p-sss. - Fix fallback-induced error in vmx. - Fix output IV in atmel-aes. - Fix empty GCM hash in mediatek. Others: - Fix DoS potential in lib/mpi. - Fix potential out-of-order issues with padata" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (162 commits) lib/mpi: call cond_resched() from mpi_powm() loop crypto: stm32/hash - Fix return issue on update crypto: dh - Remove pointless checks for NULL 'p' and 'g' crypto: qat - Clean up error handling in qat_dh_set_secret() crypto: dh - Don't permit 'key' or 'g' size longer than 'p' crypto: dh - Don't permit 'p' to be 0 crypto: dh - Fix double free of ctx->p hwrng: iproc-rng200 - Add support for BCM7278 dt-bindings: rng: Document BCM7278 RNG200 compatible crypto: chcr - Replace _manual_ swap with swap macro crypto: marvell - Add a NULL entry at the end of mv_cesa_plat_id_table[] hwrng: virtio - Virtio RNG devices need to be re-registered after suspend/resume crypto: atmel - remove empty functions crypto: ecdh - remove empty exit() MAINTAINERS: update maintainer for qat crypto: caam - remove unused param of ctx_map_to_sec4_sg() crypto: caam - remove unneeded edesc zeroization crypto: atmel-aes - Reset the controller before each use crypto: atmel-aes - properly set IV after {en,de}crypt hwrng: core - Reset user selected rng by writing "" to rng_current ...
2017-11-07Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar5-0/+5
Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-03fscrypt: move to generic async completionGilad Ben-Yossef4-82/+13
fscrypt starts several async. crypto ops and waiting for them to complete. Move it over to generic code doing the same. Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman5-0/+5
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-31fscrypt: lock mutex before checking for bounce page poolEric Biggers1-5/+2
fscrypt_initialize(), which allocates the global bounce page pool when an encrypted file is first accessed, uses "double-checked locking" to try to avoid locking fscrypt_init_mutex. However, it doesn't use any memory barriers, so it's theoretically possible for a thread to observe a bounce page pool which has not been fully initialized. This is a classic bug with "double-checked locking". While "only a theoretical issue" in the latest kernel, in pre-4.8 kernels the pointer that was checked was not even the last to be initialized, so it was easily possible for a crash (NULL pointer dereference) to happen. This was changed only incidentally by the large refactor to use fs/crypto/. Solve both problems in a trivial way that can easily be backported: just always take the mutex. It's theoretically less efficient, but it shouldn't be noticeable in practice as the mutex is only acquired very briefly once per encrypted file. Later I'd like to make this use a helper macro like DO_ONCE(). However, DO_ONCE() runs in atomic context, so we'd need to add a new macro that allows blocking. Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-25locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland1-1/+1
to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-19fscrypt: new helper function - fscrypt_prepare_lookup()Eric Biggers1-0/+18
Introduce a helper function which prepares to look up the given dentry in the given directory. If the directory is encrypted, it handles loading the directory's encryption key, setting the dentry's ->d_op to fscrypt_d_ops, and setting DCACHE_ENCRYPTED_WITH_KEY if the directory's encryption key is available. Note: once all filesystems switch over to this, we'll be able to move fscrypt_d_ops and fscrypt_set_encrypted_dentry() to fscrypt_private.h. Acked-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-19fscrypt: new helper function - fscrypt_prepare_rename()Eric Biggers1-0/+30
Introduce a helper function which prepares to rename a file into a possibly encrypted directory. It handles loading the encryption keys for the source and target directories if needed, and it handles enforcing that if the target directory (and the source directory for a cross-rename) is encrypted, then the file being moved into the directory has the same encryption policy as its containing directory. Acked-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-19fscrypt: new helper function - fscrypt_prepare_link()Eric Biggers1-0/+15
Introduce a helper function which prepares to link an inode into a possibly-encrypted directory. It handles setting up the target directory's encryption key, then verifying that the link won't violate the constraint that all files in an encrypted directory tree use the same encryption policy. Acked-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-19fscrypt: new helper function - fscrypt_file_open()Eric Biggers2-1/+50
Add a helper function which prepares to open a regular file which may be encrypted. It handles setting up the file's encryption key, then checking that the file's encryption policy matches that of its parent directory (if the parent directory is encrypted). It may be set as the ->open() method or it can be called from another ->open() method. Acked-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-19fscrypt: switch from ->is_encrypted() to IS_ENCRYPTED()Eric Biggers4-7/+6
IS_ENCRYPTED() now gives the same information as i_sb->s_cop->is_encrypted() but is more efficient, since IS_ENCRYPTED() is just a simple flag check. Prepare to remove ->is_encrypted() by switching all callers to IS_ENCRYPTED(). Acked-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-19fscrypt: clean up include file messDave Chinner1-1/+2
Filesystems have to include different header files based on whether they are compiled with encryption support or not. That's nasty and messy. Instead, rationalise the headers so we have a single include fscrypt.h and let it decide what internal implementation to include based on the __FS_HAS_ENCRYPTION define. Filesystems set __FS_HAS_ENCRYPTION to 1 before including linux/fscrypt.h if they are built with encryption support. Otherwise, they must set __FS_HAS_ENCRYPTION to 0. Add guards to prevent fscrypt_supp.h and fscrypt_notsupp.h from being directly included by filesystems. Signed-off-by: Dave Chinner <dchinner@redhat.com> [EB: use 1 and 0 rather than defined/undefined] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-10-12fscrypt: fix dereference of NULL user_key_payloadEric Biggers1-0/+5
When an fscrypt-encrypted file is opened, we request the file's master key from the keyrings service as a logon key, then access its payload. However, a revoked key has a NULL payload, and we failed to check for this. request_key() *does* skip revoked keys, but there is still a window where the key can be revoked before we acquire its semaphore. Fix it by checking for a NULL payload, treating it like a key which was already revoked at the time it was requested. Fixes: 88bd6ccdcdd6 ("ext4 crypto: add encryption key management facilities") Reviewed-by: James Morris <james.l.morris@oracle.com> Cc: <stable@vger.kernel.org> [v4.1+] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-08-23block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig1-1/+1
This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-09Merge tag 'ext4_for_linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: "The first major feature for ext4 this merge window is the largedir feature, which allows ext4 directories to support over 2 billion directory entries (assuming ~64 byte file names; in practice, users will run into practical performance limits first.) This feature was originally written by the Lustre team, and credit goes to Artem Blagodarenko from Seagate for getting this feature upstream. The second major major feature allows ext4 to support extended attribute values up to 64k. This feature was also originally from Lustre, and has been enhanced by Tahsin Erdogan from Google with a deduplication feature so that if multiple files have the same xattr value (for example, Windows ACL's stored by Samba), only one copy will be stored on disk for encoding and caching efficiency. We also have the usual set of bug fixes, cleanups, and optimizations" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (47 commits) ext4: fix spelling mistake: "prellocated" -> "preallocated" ext4: fix __ext4_new_inode() journal credits calculation ext4: skip ext4_init_security() and encryption on ea_inodes fs: generic_block_bmap(): initialize all of the fields in the temp bh ext4: change fast symlink test to not rely on i_blocks ext4: require key for truncate(2) of encrypted file ext4: don't bother checking for encryption key in ->mmap() ext4: check return value of kstrtoull correctly in reserved_clusters_store ext4: fix off-by-one fsmap error on 1k block filesystems ext4: return EFSBADCRC if a bad checksum error is found in ext4_find_entry() ext4: return EIO on read error in ext4_find_entry ext4: forbid encrypting root directory ext4: send parallel discards on commit completions ext4: avoid unnecessary stalls in ext4_evict_inode() ext4: add nombcache mount option ext4: strong binding of xattr inode references ext4: eliminate xattr entry e_hash recalculation for removes ext4: reserve space for xattr entries/names quota: add get_inode_usage callback to transfer multi-inode charges ext4: xattr inode deduplication ...