kernel/fs/crypto, branch linux-5.1.y

fscrypt: clean up some BUG_ON()s in block encryption/decryption

2019-07-26T07:12:27Z

[ Upstream commit eeacfdc68a104967162dfcba60f53f6f5b62a334 ] Replace some BUG_ON()s with WARN_ON_ONCE() and returning an error code, and move the check for len divisible by FS_CRYPTO_BLOCK_SIZE into fscrypt_crypt_block() so that it's done for both encryption and decryption, not just encryption. Reviewed-by: Chandan Rajendra Signed-off-by: Eric Biggers Signed-off-by: Sasha Levin

fscrypt: don't set policy for a dead directory

2019-07-14T06:09:46Z

commit 5858bdad4d0d0fc18bf29f34c3ac836e0b59441f upstream. The directory may have been removed when entering fscrypt_ioctl_set_policy(). If so, the empty_dir() check will return error for ext4 file system. ext4_rmdir() sets i_size = 0, then ext4_empty_dir() reports an error because 'inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)'. If the fs is mounted with errors=panic, it will trigger a panic issue. Add the check IS_DEADDIR() to fix this problem. Fixes: 9bd8212f981e ("ext4 crypto: add encryption policy and password salt support") Cc: # v4.1+ Signed-off-by: Hongjie Fang Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman

fscrypt: use READ_ONCE() to access ->i_crypt_info

2019-05-31T13:43:32Z

[ Upstream commit e37a784d8b6a1e726de5ddc7b4809c086a08db09 ] ->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 Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt

2019-03-09T18:54:24Z

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

Merge tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block

2019-03-08T22:12:17Z

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 ...

block: allow bio_for_each_segment_all() to iterate over multi-page bvec

2019-02-15T15:40:11Z

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 Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

crypto: clarify name of WEAK_KEY request flag

2019-01-25T10:41:52Z

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 Signed-off-by: Herbert Xu

fscrypt: return -EXDEV for incompatible rename or link into encrypted dir

2019-01-24T04:56:43Z

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 Cc: Joe Richey Signed-off-by: Eric Biggers

fscrypt: remove filesystem specific build config option

2019-01-24T04:56:43Z

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 Signed-off-by: Chandan Rajendra Signed-off-by: Eric Biggers

fscrypt: remove CRYPTO_CTR dependency

2019-01-24T04:56:43Z

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