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path: root/fs/crypto/fname.c
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2018-05-20fscrypt: use a common logging functionEric Biggers
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: make fscrypt_operations.max_namelen an integerEric Biggers
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 Biggers
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 Biggers
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 Biggers
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: remove error messages for skcipher_request_alloc() failureEric Biggers
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>
2018-01-11fscrypt: fix up fscrypt_fname_encrypted_size() for internal useEric Biggers
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 Biggers
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 Biggers
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: remove fscrypt_fname_usr_to_disk()Eric Biggers
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>
2018-01-11fscrypt: new helper functions for ->symlink()Eric Biggers
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>
2018-01-11fscrypt: trim down fscrypt.h includesEric Biggers
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>
2018-01-11fscrypt: move fscrypt_is_dot_dotdot() to fs/crypto/fname.cEric Biggers
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>
2017-11-14Merge tag 'fscrypt-for-linus' of ↵Linus Torvalds
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 Torvalds
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 ...
2017-11-03fscrypt: move to generic async completionGilad Ben-Yossef
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-Hartman
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>
2017-10-18fscrypt: switch from ->is_encrypted() to IS_ENCRYPTED()Eric Biggers
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>
2017-06-23fscrypt: inline fscrypt_free_filename()Eric Biggers
fscrypt_free_filename() only needs to do a kfree() of crypto_buf.name, which works well as an inline function. We can skip setting the various pointers to NULL, since no user cares about it (the name is always freed just before it goes out of scope). Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: David Gstir <david@sigma-star.at> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-04fscrypt: introduce helper function for filename matchingEric Biggers
Introduce a helper function fscrypt_match_name() which tests whether a fscrypt_name matches a directory entry. Also clean up the magic numbers and document things properly. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-04fscrypt: avoid collisions when presenting long encrypted filenamesEric Biggers
When accessing an encrypted directory without the key, userspace must operate on filenames derived from the ciphertext names, which contain arbitrary bytes. Since we must support filenames as long as NAME_MAX, we can't always just base64-encode the ciphertext, since that may make it too long. Currently, this is solved by presenting long names in an abbreviated form containing any needed filesystem-specific hashes (e.g. to identify a directory block), then the last 16 bytes of ciphertext. This needs to be sufficient to identify the actual name on lookup. However, there is a bug. It seems to have been assumed that due to the use of a CBC (ciphertext block chaining)-based encryption mode, the last 16 bytes (i.e. the AES block size) of ciphertext would depend on the full plaintext, preventing collisions. However, we actually use CBC with ciphertext stealing (CTS), which handles the last two blocks specially, causing them to appear "flipped". Thus, it's actually the second-to-last block which depends on the full plaintext. This caused long filenames that differ only near the end of their plaintexts to, when observed without the key, point to the wrong inode and be undeletable. For example, with ext4: # echo pass | e4crypt add_key -p 16 edir/ # seq -f "edir/abcdefghijklmnopqrstuvwxyz012345%.0f" 100000 | xargs touch # find edir/ -type f | xargs stat -c %i | sort | uniq | wc -l 100000 # sync # echo 3 > /proc/sys/vm/drop_caches # keyctl new_session # find edir/ -type f | xargs stat -c %i | sort | uniq | wc -l 2004 # rm -rf edir/ rm: cannot remove 'edir/_A7nNFi3rhkEQlJ6P,hdzluhODKOeWx5V': Structure needs cleaning ... To fix this, when presenting long encrypted filenames, encode the second-to-last block of ciphertext rather than the last 16 bytes. Although it would be nice to solve this without depending on a specific encryption mode, that would mean doing a cryptographic hash like SHA-256 which would be much less efficient. This way is sufficient for now, and it's still compatible with encryption modes like HEH which are strong pseudorandom permutations. Also, changing the presented names is still allowed at any time because they are only provided to allow applications to do things like delete encrypted directories. They're not designed to be used to persistently identify files --- which would be hard to do anyway, given that they're encrypted after all. For ease of backports, this patch only makes the minimal fix to both ext4 and f2fs. It leaves ubifs as-is, since ubifs doesn't compare the ciphertext block yet. Follow-on patches will clean things up properly and make the filesystems use a shared helper function. Fixes: 5de0b4d0cd15 ("ext4 crypto: simplify and speed up filename encryption") Reported-by: Gwendal Grignou <gwendal@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-03-15fscrypt: remove broken support for detecting keyring key revocationEric Biggers
Filesystem encryption ostensibly supported revoking a keyring key that had been used to "unlock" encrypted files, causing those files to become "locked" again. This was, however, buggy for several reasons, the most severe of which was that when key revocation happened to be detected for an inode, its fscrypt_info was immediately freed, even while other threads could be using it for encryption or decryption concurrently. This could be exploited to crash the kernel or worse. This patch fixes the use-after-free by removing the code which detects the keyring key having been revoked, invalidated, or expired. Instead, an encrypted inode that is "unlocked" now simply remains unlocked until it is evicted from memory. Note that this is no worse than the case for block device-level encryption, e.g. dm-crypt, and it still remains possible for a privileged user to evict unused pages, inodes, and dentries by running 'sync; echo 3 > /proc/sys/vm/drop_caches', or by simply unmounting the filesystem. In fact, one of those actions was already needed anyway for key revocation to work even somewhat sanely. This change is not expected to break any applications. In the future I'd like to implement a real API for fscrypt key revocation that interacts sanely with ongoing filesystem operations --- waiting for existing operations to complete and blocking new operations, and invalidating and sanitizing key material and plaintext from the VFS caches. But this is a hard problem, and for now this bug must be fixed. This bug affected almost all versions of ext4, f2fs, and ubifs encryption, and it was potentially reachable in any kernel configured with encryption support (CONFIG_EXT4_ENCRYPTION=y, CONFIG_EXT4_FS_ENCRYPTION=y, CONFIG_F2FS_FS_ENCRYPTION=y, or CONFIG_UBIFS_FS_ENCRYPTION=y). Note that older kernels did not use the shared fs/crypto/ code, but due to the potential security implications of this bug, it may still be worthwhile to backport this fix to them. Fixes: b7236e21d55f ("ext4 crypto: reorganize how we store keys in the inode") Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Acked-by: Michael Halcrow <mhalcrow@google.com>
2016-12-31fscrypt: use ENOKEY when file cannot be created w/o keyEric Biggers
As part of an effort to clean up fscrypt-related error codes, make attempting to create a file in an encrypted directory that hasn't been "unlocked" fail with ENOKEY. Previously, several error codes were used for this case, including ENOENT, EACCES, and EPERM, and they were not consistent between and within filesystems. ENOKEY is a better choice because it expresses that the failure is due to lacking the encryption key. It also matches the error code returned when trying to open an encrypted regular file without the key. I am not aware of any users who might be relying on the previous inconsistent error codes, which were never documented anywhere. This failure case will be exercised by an xfstest. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-12-11fscrypt: rename get_crypt_info() to fscrypt_get_crypt_info()Theodore Ts'o
To avoid namespace collisions, rename get_crypt_info() to fscrypt_get_crypt_info(). The function is only used inside the fs/crypto directory, so declare it in the new header file, fscrypt_private.h. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Eric Biggers <ebiggers@google.com>
2016-11-13fscrypto: don't use on-stack buffer for filename encryptionEric Biggers
With the new (in 4.9) option to use a virtually-mapped stack (CONFIG_VMAP_STACK), stack buffers cannot be used as input/output for the scatterlist crypto API because they may not be directly mappable to struct page. For short filenames, fname_encrypt() was encrypting a stack buffer holding the padded filename. Fix it by encrypting the filename in-place in the output buffer, thereby making the temporary buffer unnecessary. This bug could most easily be observed in a CONFIG_DEBUG_SG kernel because this allowed the BUG in sg_set_buf() to be triggered. Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-11-13fscrypt: Constify struct inode pointerDavid Gstir
Some filesystems, such as UBIFS, maintain a const pointer for struct inode. Signed-off-by: David Gstir <david@sigma-star.at> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-09-30fscrypto: use standard macros to compute length of fname ciphertextEric Biggers
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-09-15fscrypto: make filename crypto functions return 0 on successEric Biggers
Several filename crypto functions: fname_decrypt(), fscrypt_fname_disk_to_usr(), and fscrypt_fname_usr_to_disk(), returned the output length on success or -errno on failure. However, the output length was redundant with the value written to 'oname->len'. It is also potentially error-prone to make callers have to check for '< 0' instead of '!= 0'. Therefore, make these functions return 0 instead of a length, and make the callers who cared about the return value being a length use 'oname->len' instead. For consistency also make other callers check for a nonzero result rather than a negative result. This change also fixes the inconsistency of fname_encrypt() actually already returning 0 on success, not a length like the other filename crypto functions and as documented in its function comment. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-09-15fscrypto: rename completion callbacks to reflect usageEric Biggers
fscrypt_complete() was used only for data pages, not for all encryption/decryption. Rename it to page_crypt_complete(). dir_crypt_complete() was used for filename encryption/decryption for both directory entries and symbolic links. Rename it to fname_crypt_complete(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-09-15fscrypto: remove unnecessary includesEric Biggers
This patch removes some #includes that are clearly not needed, such as a reference to ecryptfs, which is unrelated to the new filesystem encryption code. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-03-21Merge tag 'for-f2fs-4.6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs Pull f2fs updates from Jaegeuk Kim: "New Features: - uplift filesystem encryption into fs/crypto/ - give sysfs entries to control memroy consumption Enhancements: - aio performance by preallocating blocks in ->write_iter - use writepages lock for only WB_SYNC_ALL - avoid redundant inline_data conversion - enhance forground GC - use wait_for_stable_page as possible - speed up SEEK_DATA and fiiemap Bug Fixes: - corner case in terms of -ENOSPC for inline_data - hung task caused by long latency in shrinker - corruption between atomic write and f2fs_trace_pid - avoid garbage lengths in dentries - revoke atomicly written pages if an error occurs In addition, there are various minor bug fixes and clean-ups" * tag 'for-f2fs-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (81 commits) f2fs: submit node page write bios when really required f2fs: add missing argument to f2fs_setxattr stub f2fs: fix to avoid unneeded unlock_new_inode f2fs: clean up opened code with f2fs_update_dentry f2fs: declare static functions f2fs: use cryptoapi crc32 functions f2fs: modify the readahead method in ra_node_page() f2fs crypto: sync ext4_lookup and ext4_file_open fs crypto: move per-file encryption from f2fs tree to fs/crypto f2fs: mutex can't be used by down_write_nest_lock() f2fs: recovery missing dot dentries in root directory f2fs: fix to avoid deadlock when merging inline data f2fs: introduce f2fs_flush_merged_bios for cleanup f2fs: introduce f2fs_update_data_blkaddr for cleanup f2fs crypto: fix incorrect positioning for GCing encrypted data page f2fs: fix incorrect upper bound when iterating inode mapping tree f2fs: avoid hungtask problem caused by losing wake_up f2fs: trace old block address for CoWed page f2fs: try to flush inode after merging inline data f2fs: show more info about superblock recovery ...
2016-03-17fs crypto: move per-file encryption from f2fs tree to fs/cryptoJaegeuk Kim
This patch adds the renamed functions moved from the f2fs crypto files. 1. definitions for per-file encryption used by ext4 and f2fs. 2. crypto.c for encrypt/decrypt functions a. IO preparation: - fscrypt_get_ctx / fscrypt_release_ctx b. before IOs: - fscrypt_encrypt_page - fscrypt_decrypt_page - fscrypt_zeroout_range c. after IOs: - fscrypt_decrypt_bio_pages - fscrypt_pullback_bio_page - fscrypt_restore_control_page 3. policy.c supporting context management. a. For ioctls: - fscrypt_process_policy - fscrypt_get_policy b. For context permission - fscrypt_has_permitted_context - fscrypt_inherit_context 4. keyinfo.c to handle permissions - fscrypt_get_encryption_info - fscrypt_free_encryption_info 5. fname.c to support filename encryption a. general wrapper functions - fscrypt_fname_disk_to_usr - fscrypt_fname_usr_to_disk - fscrypt_setup_filename - fscrypt_free_filename b. specific filename handling functions - fscrypt_fname_alloc_buffer - fscrypt_fname_free_buffer 6. Makefile and Kconfig Cc: Al Viro <viro@ftp.linux.org.uk> Signed-off-by: Michael Halcrow <mhalcrow@google.com> Signed-off-by: Ildar Muslukhov <ildarm@google.com> Signed-off-by: Uday Savagaonkar <savagaon@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>