On Sat, Jun 05, 2021 at 12:50:33AM -0700, Eric Biggers wrote: > From: Eric Biggers <[email protected]> > > 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: aa408f835d02 ("fscrypt: derive dirhash key for casefolded directories") > Fixes: e3b1078bedd3 ("fscrypt: add support for IV_INO_LBLK_32 policies") > Cc: <[email protected]> # v5.6+ > Signed-off-by: Eric Biggers <[email protected]> > --- > > v2: Fixed fscrypt_setup_iv_ino_lblk_32_key() too, not just > fscrypt_derive_dirhash_key(). > > fs/crypto/keysetup.c | 40 ++++++++++++++++++++++++++++++++-------- > 1 file changed, 32 insertions(+), 8 deletions(-) >
Applied to fscrypt.git#master for 5.14. - Eric _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
