diff options
author | Ard Biesheuvel <ardb@kernel.org> | 2021-02-01 21:02:29 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-04 13:38:31 +0300 |
commit | 84c93e8897bbf91c3d1813a10e38591a1af267eb (patch) | |
tree | 8eb0f014c45dcb0aeaa434dd20ad6888c417e791 /crypto/michael_mic.c | |
parent | 6e3b6710ea2ed9acbf10b548443c1df4845c470d (diff) | |
download | linux-84c93e8897bbf91c3d1813a10e38591a1af267eb.tar.xz |
crypto: michael_mic - fix broken misalignment handling
commit e1b2d980f03b833442768c1987d5ad0b9a58cfe7 upstream.
The Michael MIC driver uses the cra_alignmask to ensure that pointers
presented to its update and finup/final methods are 32-bit aligned.
However, due to the way the shash API works, this is no guarantee that
the 32-bit reads occurring in the update method are also aligned, as the
size of the buffer presented to update may be of uneven length. For
instance, an update() of 3 bytes followed by a misaligned update() of 4
or more bytes will result in a misaligned access using an accessor that
is not suitable for this.
On most architectures, this does not matter, and so setting the
cra_alignmask is pointless. On architectures where this does matter,
setting the cra_alignmask does not actually solve the problem.
So let's get rid of the cra_alignmask, and use unaligned accessors
instead, where appropriate.
Cc: <stable@vger.kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'crypto/michael_mic.c')
-rw-r--r-- | crypto/michael_mic.c | 31 |
1 files changed, 12 insertions, 19 deletions
diff --git a/crypto/michael_mic.c b/crypto/michael_mic.c index 63350c4ad461..f4c31049601c 100644 --- a/crypto/michael_mic.c +++ b/crypto/michael_mic.c @@ -7,7 +7,7 @@ * Copyright (c) 2004 Jouni Malinen <j@w1.fi> */ #include <crypto/internal/hash.h> -#include <asm/byteorder.h> +#include <asm/unaligned.h> #include <linux/init.h> #include <linux/module.h> #include <linux/string.h> @@ -19,7 +19,7 @@ struct michael_mic_ctx { }; struct michael_mic_desc_ctx { - u8 pending[4]; + __le32 pending; size_t pending_len; u32 l, r; @@ -60,13 +60,12 @@ static int michael_update(struct shash_desc *desc, const u8 *data, unsigned int len) { struct michael_mic_desc_ctx *mctx = shash_desc_ctx(desc); - const __le32 *src; if (mctx->pending_len) { int flen = 4 - mctx->pending_len; if (flen > len) flen = len; - memcpy(&mctx->pending[mctx->pending_len], data, flen); + memcpy((u8 *)&mctx->pending + mctx->pending_len, data, flen); mctx->pending_len += flen; data += flen; len -= flen; @@ -74,23 +73,21 @@ static int michael_update(struct shash_desc *desc, const u8 *data, if (mctx->pending_len < 4) return 0; - src = (const __le32 *)mctx->pending; - mctx->l ^= le32_to_cpup(src); + mctx->l ^= le32_to_cpu(mctx->pending); michael_block(mctx->l, mctx->r); mctx->pending_len = 0; } - src = (const __le32 *)data; - while (len >= 4) { - mctx->l ^= le32_to_cpup(src++); + mctx->l ^= get_unaligned_le32(data); michael_block(mctx->l, mctx->r); + data += 4; len -= 4; } if (len > 0) { mctx->pending_len = len; - memcpy(mctx->pending, src, len); + memcpy(&mctx->pending, data, len); } return 0; @@ -100,8 +97,7 @@ static int michael_update(struct shash_desc *desc, const u8 *data, static int michael_final(struct shash_desc *desc, u8 *out) { struct michael_mic_desc_ctx *mctx = shash_desc_ctx(desc); - u8 *data = mctx->pending; - __le32 *dst = (__le32 *)out; + u8 *data = (u8 *)&mctx->pending; /* Last block and padding (0x5a, 4..7 x 0) */ switch (mctx->pending_len) { @@ -123,8 +119,8 @@ static int michael_final(struct shash_desc *desc, u8 *out) /* l ^= 0; */ michael_block(mctx->l, mctx->r); - dst[0] = cpu_to_le32(mctx->l); - dst[1] = cpu_to_le32(mctx->r); + put_unaligned_le32(mctx->l, out); + put_unaligned_le32(mctx->r, out + 4); return 0; } @@ -135,13 +131,11 @@ static int michael_setkey(struct crypto_shash *tfm, const u8 *key, { struct michael_mic_ctx *mctx = crypto_shash_ctx(tfm); - const __le32 *data = (const __le32 *)key; - if (keylen != 8) return -EINVAL; - mctx->l = le32_to_cpu(data[0]); - mctx->r = le32_to_cpu(data[1]); + mctx->l = get_unaligned_le32(key); + mctx->r = get_unaligned_le32(key + 4); return 0; } @@ -156,7 +150,6 @@ static struct shash_alg alg = { .cra_name = "michael_mic", .cra_driver_name = "michael_mic-generic", .cra_blocksize = 8, - .cra_alignmask = 3, .cra_ctxsize = sizeof(struct michael_mic_ctx), .cra_module = THIS_MODULE, } |