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2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner2-0/+2
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier for more missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-07Merge tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscryptLinus Torvalds6-67/+119
Pull fscrypt updates from Ted Ts'o: "Clean up fscrypt's dcache revalidation support, and other miscellaneous cleanups" * tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt: fscrypt: cache decrypted symlink target in ->i_link vfs: use READ_ONCE() to access ->i_link fscrypt: fix race where ->lookup() marks plaintext dentry as ciphertext fscrypt: only set dentry_operations on ciphertext dentries fs, fscrypt: clear DCACHE_ENCRYPTED_NAME when unaliasing directory fscrypt: fix race allowing rename() and link() of ciphertext dentries fscrypt: clean up and improve dentry revalidation fscrypt: use READ_ONCE() to access ->i_crypt_info fscrypt: remove WARN_ON_ONCE() when decryption fails fscrypt: drop inode argument from fscrypt_get_ctx()
2019-05-07Merge tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-blockLinus Torvalds1-2/+1
Pull block updates from Jens Axboe: "Nothing major in this series, just fixes and improvements all over the map. This contains: - Series of fixes for sed-opal (David, Jonas) - Fixes and performance tweaks for BFQ (via Paolo) - Set of fixes for bcache (via Coly) - Set of fixes for md (via Song) - Enabling multi-page for passthrough requests (Ming) - Queue release fix series (Ming) - Device notification improvements (Martin) - Propagate underlying device rotational status in loop (Holger) - Removal of mtip32xx trim support, which has been disabled for years (Christoph) - Improvement and cleanup of nvme command handling (Christoph) - Add block SPDX tags (Christoph) - Cleanup/hardening of bio/bvec iteration (Christoph) - A few NVMe pull requests (Christoph) - Removal of CONFIG_LBDAF (Christoph) - Various little fixes here and there" * tag 'for-5.2/block-20190507' of git://git.kernel.dk/linux-block: (164 commits) block: fix mismerge in bvec_advance block: don't drain in-progress dispatch in blk_cleanup_queue() blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_release blk-mq: always free hctx after request queue is freed blk-mq: split blk_mq_alloc_and_init_hctx into two parts blk-mq: free hw queue's resource in hctx's release handler blk-mq: move cancel of requeue_work into blk_mq_release blk-mq: grab .q_usage_counter when queuing request from plug code path block: fix function name in comment nvmet: protect discovery change log event list iteration nvme: mark nvme_core_init and nvme_core_exit static nvme: move command size checks to the core nvme-fabrics: check more command sizes nvme-pci: check more command sizes nvme-pci: remove an unneeded variable initialization nvme-pci: unquiesce admin queue on shutdown nvme-pci: shutdown on timeout during deletion nvme-pci: fix psdt field for single segment sgls nvme-multipath: don't print ANA group state by default nvme-multipath: split bios with the ns_head bio_set before submitting ...
2019-04-30block: remove the i argument to bio_for_each_segment_allChristoph Hellwig1-2/+1
We only have two callers that need the integer loop iterator, and they can easily maintain it themselves. Suggested-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: David Sterba <dsterba@suse.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Coly Li <colyli@suse.de> Reviewed-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-25crypto: shash - remove shash_desc::flagsEric Biggers1-1/+0
The flags field in 'struct shash_desc' never actually does anything. The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP. However, no shash algorithm ever sleeps, making this flag a no-op. With this being the case, inevitably some users who can't sleep wrongly pass MAY_SLEEP. These would all need to be fixed if any shash algorithm actually started sleeping. For example, the shash_ahash_*() functions, which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP from the ahash API to the shash API. However, the shash functions are called under kmap_atomic(), so actually they're assumed to never sleep. Even if it turns out that some users do need preemption points while hashing large buffers, we could easily provide a helper function crypto_shash_update_large() which divides the data into smaller chunks and calls crypto_shash_update() and cond_resched() for each chunk. It's not necessary to have a flag in 'struct shash_desc', nor is it necessary to make individual shash algorithms aware of this at all. Therefore, remove shash_desc::flags, and document that the crypto_shash_*() functions can be called from any context. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-04-17fscrypt: cache decrypted symlink target in ->i_linkEric Biggers2-7/+54
Path lookups that traverse encrypted symlink(s) are very slow because each encrypted symlink needs to be decrypted each time it's followed. This also involves dropping out of rcu-walk mode. Make encrypted symlinks faster by caching the decrypted symlink target in ->i_link. The first call to fscrypt_get_symlink() sets it. Then, the existing VFS path lookup code uses the non-NULL ->i_link to take the fast path where ->get_link() isn't called, and lookups in rcu-walk mode remain in rcu-walk mode. Also set ->i_link immediately when a new encrypted symlink is created. To safely free the symlink target after an RCU grace period has elapsed, introduce a new function fscrypt_free_inode(), and make the relevant filesystems call it just before actually freeing the inode. Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-17fscrypt: fix race where ->lookup() marks plaintext dentry as ciphertextEric Biggers2-5/+7
->lookup() in an encrypted directory begins as follows: 1. fscrypt_prepare_lookup(): a. Try to load the directory's encryption key. b. If the key is unavailable, mark the dentry as a ciphertext name via d_flags. 2. fscrypt_setup_filename(): a. Try to load the directory's encryption key. b. If the key is available, encrypt the name (treated as a plaintext name) to get the on-disk name. Otherwise decode the name (treated as a ciphertext name) to get the on-disk name. But if the key is concurrently added, it may be found at (2a) but not at (1a). In this case, the dentry will be wrongly marked as a ciphertext name even though it was actually treated as plaintext. This will cause the dentry to be wrongly invalidated on the next lookup, potentially causing problems. For example, if the racy ->lookup() was part of sys_mount(), then the new mount will be detached when anything tries to access it. This is despite the mountpoint having a plaintext path, which should remain valid now that the key was added. Of course, this is only possible if there's a userspace race. Still, the additional kernel-side race is confusing and unexpected. Close the kernel-side race by changing fscrypt_prepare_lookup() to also set the on-disk filename (step 2b), consistent with the d_flags update. Fixes: 28b4c263961c ("ext4 crypto: revalidate dentry after adding or removing the key") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-17fscrypt: only set dentry_operations on ciphertext dentriesEric Biggers1-2/+1
Plaintext dentries are always valid, so only set fscrypt_d_ops on ciphertext dentries. Besides marginally improved performance, this allows overlayfs to use an fscrypt-encrypted upperdir, provided that all the following are true: (1) The fscrypt encryption key is placed in the keyring before mounting overlayfs, and remains while the overlayfs is mounted. (2) The overlayfs workdir uses the same encryption policy. (3) No dentries for the ciphertext names of subdirectories have been created in the upperdir or workdir yet. (Since otherwise d_splice_alias() will reuse the old dentry with ->d_op set.) One potential use case is using an ephemeral encryption key to encrypt all files created or changed by a container, so that they can be securely erased ("crypto-shredded") after the container stops. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-17fscrypt: fix race allowing rename() and link() of ciphertext dentriesEric Biggers1-1/+11
Close some race conditions where fscrypt allowed rename() and link() on ciphertext dentries that had been looked up just prior to the key being concurrently added. It's better to return -ENOKEY in this case. This avoids doing the nonsensical thing of encrypting the names a second time when searching for the actual on-disk dir entries. It also guarantees that DCACHE_ENCRYPTED_NAME dentries are never rename()d, so the dcache won't have support all possible combinations of moving DCACHE_ENCRYPTED_NAME around during __d_move(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-17fscrypt: clean up and improve dentry revalidationEric Biggers2-30/+32
Make various improvements to fscrypt dentry revalidation: - Don't try to handle the case where the per-directory key is removed, as this can't happen without the inode (and dentries) being evicted. - Flag ciphertext dentries rather than plaintext dentries, since it's ciphertext dentries that need the special handling. - Avoid doing unnecessary work for non-ciphertext dentries. - When revalidating ciphertext dentries, try to set up the directory's i_crypt_info to make sure the key is really still absent, rather than invalidating all negative dentries as the previous code did. An old comment suggested we can't do this for locking reasons, but AFAICT this comment was outdated and it actually works fine. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-16fscrypt: use READ_ONCE() to access ->i_crypt_infoEric Biggers4-8/+8
->i_crypt_info starts out NULL and may later be locklessly set to a non-NULL value by the cmpxchg() in fscrypt_get_encryption_info(). But ->i_crypt_info is used directly, which technically is incorrect. It's a data race, and it doesn't include the data dependency barrier needed to safely dereference the pointer on at least one architecture. Fix this by using READ_ONCE() instead. Note: we don't need to use smp_load_acquire(), since dereferencing the pointer only requires a data dependency barrier, which is already included in READ_ONCE(). We also don't need READ_ONCE() in places where ->i_crypt_info is unconditionally dereferenced, since it must have already been checked. Also downgrade the cmpxchg() to cmpxchg_release(), since RELEASE semantics are sufficient on the write side. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-16fscrypt: remove WARN_ON_ONCE() when decryption failsEric Biggers1-4/+2
If decrypting a block fails, fscrypt did a WARN_ON_ONCE(). But WARN is meant for kernel bugs, which this isn't; this could be hit by fuzzers using fault injection, for example. Also, there is already a proper warning message logged in fscrypt_do_page_crypto(), so the WARN doesn't add much. Just remove the unnessary WARN. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-16fscrypt: drop inode argument from fscrypt_get_ctx()Eric Biggers2-12/+6
The only reason the inode is being passed to fscrypt_get_ctx() is to verify that the encryption key is available. However, all callers already ensure this because if we get as far as trying to do I/O to an encrypted file without the key, there's already a bug. Therefore, remove this unnecessary argument. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-03-09Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscryptLinus Torvalds4-9/+7
Pull fscrypt updates from Eric Biggers: "First: Ted, Jaegeuk, and I have decided to add me as a co-maintainer for fscrypt, and we're now using a shared git tree. So we've updated MAINTAINERS accordingly, and I'm doing the pull request this time. The actual changes for v5.1 are: - Remove the fs-specific kconfig options like CONFIG_EXT4_ENCRYPTION and make fscrypt support for all fscrypt-capable filesystems be controlled by CONFIG_FS_ENCRYPTION, similar to how CONFIG_QUOTA works. - Improve error code for rename() and link() into encrypted directories. - Various cleanups" * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt: MAINTAINERS: add Eric Biggers as an fscrypt maintainer fscrypt: return -EXDEV for incompatible rename or link into encrypted dir fscrypt: remove filesystem specific build config option f2fs: use IS_ENCRYPTED() to check encryption status ext4: use IS_ENCRYPTED() to check encryption status fscrypt: remove CRYPTO_CTR dependency
2019-03-08Merge tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+2
Pull block layer updates from Jens Axboe: "Not a huge amount of changes in this round, the biggest one is that we finally have Mings multi-page bvec support merged. Apart from that, this pull request contains: - Small series that avoids quiescing the queue for sysfs changes that match what we currently have (Aleksei) - Series of bcache fixes (via Coly) - Series of lightnvm fixes (via Mathias) - NVMe pull request from Christoph. Nothing major, just SPDX/license cleanups, RR mp policy (Hannes), and little fixes (Bart, Chaitanya). - BFQ series (Paolo) - Save blk-mq cpu -> hw queue mapping, removing a pointer indirection for the fast path (Jianchao) - fops->iopoll() added for async IO polling, this is a feature that the upcoming io_uring interface will use (Christoph, me) - Partition scan loop fixes (Dongli) - mtip32xx conversion from managed resource API (Christoph) - cdrom registration race fix (Guenter) - MD pull from Song, two minor fixes. - Various documentation fixes (Marcos) - Multi-page bvec feature. This brings a lot of nice improvements with it, like more efficient splitting, larger IOs can be supported without growing the bvec table size, and so on. (Ming) - Various little fixes to core and drivers" * tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block: (117 commits) block: fix updating bio's front segment size block: Replace function name in string with __func__ nbd: propagate genlmsg_reply return code floppy: remove set but not used variable 'q' null_blk: fix checking for REQ_FUA block: fix NULL pointer dereference in register_disk fs: fix guard_bio_eod to check for real EOD errors blk-mq: use HCTX_TYPE_DEFAULT but not 0 to index blk_mq_tag_set->map block: optimize bvec iteration in bvec_iter_advance block: introduce mp_bvec_for_each_page() for iterating over page block: optimize blk_bio_segment_split for single-page bvec block: optimize __blk_segment_map_sg() for single-page bvec block: introduce bvec_nth_page() iomap: wire up the iopoll method block: add bio_set_polled() helper block: wire up block device iopoll method fs: add an iopoll method to struct file_operations loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part() loop: do not print warn message if partition scan is successful block: bounce: make sure that bvec table is updated ...
2019-02-15block: allow bio_for_each_segment_all() to iterate over multi-page bvecMing Lei1-1/+2
This patch introduces one extra iterator variable to bio_for_each_segment_all(), then we can allow bio_for_each_segment_all() to iterate over multi-page bvec. Given it is just one mechannical & simple change on all bio_for_each_segment_all() users, this patch does tree-wide change in one single patch, so that we can avoid to use a temporary helper for this conversion. Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-25crypto: clarify name of WEAK_KEY request flagEric Biggers1-2/+2
CRYPTO_TFM_REQ_WEAK_KEY confuses newcomers to the crypto API because it sounds like it is requesting a weak key. Actually, it is requesting that weak keys be forbidden (for algorithms that have the notion of "weak keys"; currently only DES and XTS do). Also it is only one letter away from CRYPTO_TFM_RES_WEAK_KEY, with which it can be easily confused. (This in fact happened in the UX500 driver, though just in some debugging messages.) Therefore, make the intent clear by renaming it to CRYPTO_TFM_REQ_FORBID_WEAK_KEYS. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-01-23fscrypt: return -EXDEV for incompatible rename or link into encrypted dirEric Biggers2-5/+4
Currently, trying to rename or link a regular file, directory, or symlink into an encrypted directory fails with EPERM when the source file is unencrypted or is encrypted with a different encryption policy, and is on the same mountpoint. It is correct for the operation to fail, but the choice of EPERM breaks tools like 'mv' that know to copy rather than rename if they see EXDEV, but don't know what to do with EPERM. Our original motivation for EPERM was to encourage users to securely handle their data. Encrypting files by "moving" them into an encrypted directory can be insecure because the unencrypted data may remain in free space on disk, where it can later be recovered by an attacker. It's much better to encrypt the data from the start, or at least try to securely delete the source data e.g. using the 'shred' program. However, the current behavior hasn't been effective at achieving its goal because users tend to be confused, hack around it, and complain; see e.g. https://github.com/google/fscrypt/issues/76. And in some cases it's actually inconsistent or unnecessary. For example, 'mv'-ing files between differently encrypted directories doesn't work even in cases where it can be secure, such as when in userspace the same passphrase protects both directories. Yet, you *can* already 'mv' unencrypted files into an encrypted directory if the source files are on a different mountpoint, even though doing so is often insecure. There are probably better ways to teach users to securely handle their files. For example, the 'fscrypt' userspace tool could provide a command that migrates unencrypted files into an encrypted directory, acting like 'shred' on the source files and providing appropriate warnings depending on the type of the source filesystem and disk. Receiving errors on unimportant files might also force some users to disable encryption, thus making the behavior counterproductive. It's desirable to make encryption as unobtrusive as possible. Therefore, change the error code from EPERM to EXDEV so that tools looking for EXDEV will fall back to a copy. This, of course, doesn't prevent users from still doing the right things to securely manage their files. Note that this also matches the behavior when a file is renamed between two project quota hierarchies; so there's precedent for using EXDEV for things other than mountpoints. xfstests generic/398 will require an update with this change. [Rewritten from an earlier patch series by Michael Halcrow.] Cc: Michael Halcrow <mhalcrow@google.com> Cc: Joe Richey <joerichey@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-01-23fscrypt: remove filesystem specific build config optionChandan Rajendra2-3/+3
In order to have a common code base for fscrypt "post read" processing for all filesystems which support encryption, this commit removes filesystem specific build config option (e.g. CONFIG_EXT4_FS_ENCRYPTION) and replaces it with a build option (i.e. CONFIG_FS_ENCRYPTION) whose value affects all the filesystems making use of fscrypt. Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-01-23fscrypt: remove CRYPTO_CTR dependencyEric Biggers1-1/+0
fscrypt doesn't use the CTR mode of operation for anything, so there's no need to select CRYPTO_CTR. It was added by commit 71dea01ea2ed ("ext4 crypto: require CONFIG_CRYPTO_CTR if ext4 encryption is enabled"). But, I've been unable to identify the arm64 crypto bug it was supposedly working around. I suspect the issue was seen only on some old Android device kernel (circa 3.10?). So if the fix wasn't mistaken, the real bug is probably already fixed. Or maybe it was actually a bug in a non-upstream crypto driver. So, remove the dependency. If it turns out there's actually still a bug, we'll fix it properly. Signed-off-by: Eric Biggers <ebiggers@google.com>
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>
2018-05-02fscrypt: 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>
2018-01-11fscrypt: 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>
2018-01-11fscrypt: 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>
2018-01-11fscrypt: 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>
2018-01-11fscrypt: 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>
2018-01-11fscrypt: 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>
2018-01-11fscrypt: 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>