Eric Biggers b5a2b5b642 fscrypt: fix derivation of SipHash keys on big endian CPUs ... commit 2fc2b430f559fdf32d5d1dd5ceaa40e12fb77bdf upstream. Typically, the cryptographic APIs that fscrypt uses take keys as byte arrays, which avoids endianness issues. However, siphash_key_t is an exception. It is defined as 'u64 key[2];', i.e. the 128-bit key is expected to be given directly as two 64-bit words in CPU endianness. fscrypt_derive_dirhash_key() and fscrypt_setup_iv_ino_lblk_32_key() forgot to take this into account. Therefore, the SipHash keys used to index encrypted+casefolded directories differ on big endian vs. little endian platforms, as do the SipHash keys used to hash inode numbers for IV_INO_LBLK_32-encrypted directories. This makes such directories non-portable between these platforms. Fix this by always using the little endian order. This is a breaking change for big endian platforms, but this should be fine in practice since these features (encrypt+casefold support, and the IV_INO_LBLK_32 flag) aren't known to actually be used on any big endian platforms yet. Fixes: aa408f835d ("fscrypt: derive dirhash key for casefolded directories") Fixes: e3b1078bed ("fscrypt: add support for IV_INO_LBLK_32 policies") Cc: <stable@vger.kernel.org> # v5.6+ Link: https://lore.kernel.org/r/20210605075033.54424-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-07-14 16:56:53 +02:00
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bio.c
crypto.c
fname.c
fscrypt_private.h
hkdf.c
hooks.c
inline_crypt.c
Kconfig
keyring.c
keysetup_v1.c
keysetup.c
Makefile
policy.c