This is a note to let you know that I've just added the patch titled
crypto: chacha20 - Fix chacha20_block() keystream alignment (again)
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
crypto-chacha20-fix-chacha20_block-keystream-alignment-again.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Jun 16 07:08:33 PM CEST 2022
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Date: Tue, 11 Sep 2018 20:05:10 -0700
Subject: crypto: chacha20 - Fix chacha20_block() keystream alignment (again)
From: Eric Biggers <ebiggers@xxxxxxxxxx>
[ Upstream commit a5e9f557098e54af44ade5d501379be18435bfbf ]
In commit 9f480faec58c ("crypto: chacha20 - Fix keystream alignment for
chacha20_block()"), I had missed that chacha20_block() can be called
directly on the buffer passed to get_random_bytes(), which can have any
alignment. So, while my commit didn't break anything, it didn't fully
solve the alignment problems.
Revert my solution and just update chacha20_block() to use
put_unaligned_le32(), so the output buffer need not be aligned.
This is simpler, and on many CPUs it's the same speed.
But, I kept the 'tmp' buffers in extract_crng_user() and
_get_random_bytes() 4-byte aligned, since that alignment is actually
needed for _crng_backtrack_protect() too.
Reported-by: Stephan Müller <smueller@xxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
crypto/chacha20_generic.c | 7 ++++---
drivers/char/random.c | 24 ++++++++++++------------
include/crypto/chacha20.h | 3 +--
lib/chacha20.c | 6 +++---
4 files changed, 20 insertions(+), 20 deletions(-)
--- a/crypto/chacha20_generic.c
+++ b/crypto/chacha20_generic.c
@@ -22,20 +22,21 @@ static inline u32 le32_to_cpuvp(const vo
static void chacha20_docrypt(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes)
{
- u32 stream[CHACHA20_BLOCK_WORDS];
+ /* aligned to potentially speed up crypto_xor() */
+ u8 stream[CHACHA20_BLOCK_SIZE] __aligned(sizeof(long));
if (dst != src)
memcpy(dst, src, bytes);
while (bytes >= CHACHA20_BLOCK_SIZE) {
chacha20_block(state, stream);
- crypto_xor(dst, (const u8 *)stream, CHACHA20_BLOCK_SIZE);
+ crypto_xor(dst, stream, CHACHA20_BLOCK_SIZE);
bytes -= CHACHA20_BLOCK_SIZE;
dst += CHACHA20_BLOCK_SIZE;
}
if (bytes) {
chacha20_block(state, stream);
- crypto_xor(dst, (const u8 *)stream, bytes);
+ crypto_xor(dst, stream, bytes);
}
}
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -485,9 +485,9 @@ static int crng_init_cnt = 0;
static unsigned long crng_global_init_time = 0;
#define CRNG_INIT_CNT_THRESH (2*CHACHA20_KEY_SIZE)
static void _extract_crng(struct crng_state *crng,
- __u32 out[CHACHA20_BLOCK_WORDS]);
+ __u8 out[CHACHA20_BLOCK_SIZE]);
static void _crng_backtrack_protect(struct crng_state *crng,
- __u32 tmp[CHACHA20_BLOCK_WORDS], int used);
+ __u8 tmp[CHACHA20_BLOCK_SIZE], int used);
static void process_random_ready_list(void);
static void _get_random_bytes(void *buf, int nbytes);
@@ -986,7 +986,7 @@ static void crng_reseed(struct crng_stat
unsigned long flags;
int i, num;
union {
- __u32 block[CHACHA20_BLOCK_WORDS];
+ __u8 block[CHACHA20_BLOCK_SIZE];
__u32 key[8];
} buf;
@@ -1014,7 +1014,7 @@ static void crng_reseed(struct crng_stat
}
static void _extract_crng(struct crng_state *crng,
- __u32 out[CHACHA20_BLOCK_WORDS])
+ __u8 out[CHACHA20_BLOCK_SIZE])
{
unsigned long flags, init_time;
@@ -1032,7 +1032,7 @@ static void _extract_crng(struct crng_st
spin_unlock_irqrestore(&crng->lock, flags);
}
-static void extract_crng(__u32 out[CHACHA20_BLOCK_WORDS])
+static void extract_crng(__u8 out[CHACHA20_BLOCK_SIZE])
{
_extract_crng(select_crng(), out);
}
@@ -1042,7 +1042,7 @@ static void extract_crng(__u32 out[CHACH
* enough) to mutate the CRNG key to provide backtracking protection.
*/
static void _crng_backtrack_protect(struct crng_state *crng,
- __u32 tmp[CHACHA20_BLOCK_WORDS], int used)
+ __u8 tmp[CHACHA20_BLOCK_SIZE], int used)
{
unsigned long flags;
__u32 *s, *d;
@@ -1054,14 +1054,14 @@ static void _crng_backtrack_protect(stru
used = 0;
}
spin_lock_irqsave(&crng->lock, flags);
- s = &tmp[used / sizeof(__u32)];
+ s = (__u32 *) &tmp[used];
d = &crng->state[4];
for (i=0; i < 8; i++)
*d++ ^= *s++;
spin_unlock_irqrestore(&crng->lock, flags);
}
-static void crng_backtrack_protect(__u32 tmp[CHACHA20_BLOCK_WORDS], int used)
+static void crng_backtrack_protect(__u8 tmp[CHACHA20_BLOCK_SIZE], int used)
{
_crng_backtrack_protect(select_crng(), tmp, used);
}
@@ -1069,7 +1069,7 @@ static void crng_backtrack_protect(__u32
static ssize_t extract_crng_user(void __user *buf, size_t nbytes)
{
ssize_t ret = 0, i = CHACHA20_BLOCK_SIZE;
- __u32 tmp[CHACHA20_BLOCK_WORDS];
+ __u8 tmp[CHACHA20_BLOCK_SIZE] __aligned(4);
int large_request = (nbytes > 256);
while (nbytes) {
@@ -1529,7 +1529,7 @@ static void _warn_unseeded_randomness(co
*/
static void _get_random_bytes(void *buf, int nbytes)
{
- __u32 tmp[CHACHA20_BLOCK_WORDS];
+ __u8 tmp[CHACHA20_BLOCK_SIZE] __aligned(4);
trace_get_random_bytes(nbytes, _RET_IP_);
@@ -2116,7 +2116,7 @@ u64 get_random_u64(void)
batch = raw_cpu_ptr(&batched_entropy_u64);
spin_lock_irqsave(&batch->batch_lock, flags);
if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) {
- extract_crng((__u32 *)batch->entropy_u64);
+ extract_crng((u8 *)batch->entropy_u64);
batch->position = 0;
}
ret = batch->entropy_u64[batch->position++];
@@ -2140,7 +2140,7 @@ u32 get_random_u32(void)
batch = raw_cpu_ptr(&batched_entropy_u32);
spin_lock_irqsave(&batch->batch_lock, flags);
if (batch->position % ARRAY_SIZE(batch->entropy_u32) == 0) {
- extract_crng(batch->entropy_u32);
+ extract_crng((u8 *)batch->entropy_u32);
batch->position = 0;
}
ret = batch->entropy_u32[batch->position++];
--- a/include/crypto/chacha20.h
+++ b/include/crypto/chacha20.h
@@ -13,13 +13,12 @@
#define CHACHA20_IV_SIZE 16
#define CHACHA20_KEY_SIZE 32
#define CHACHA20_BLOCK_SIZE 64
-#define CHACHA20_BLOCK_WORDS (CHACHA20_BLOCK_SIZE / sizeof(u32))
struct chacha20_ctx {
u32 key[8];
};
-void chacha20_block(u32 *state, u32 *stream);
+void chacha20_block(u32 *state, u8 *stream);
void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv);
int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
unsigned int keysize);
--- a/lib/chacha20.c
+++ b/lib/chacha20.c
@@ -21,9 +21,9 @@ static inline u32 rotl32(u32 v, u8 n)
return (v << n) | (v >> (sizeof(v) * 8 - n));
}
-void chacha20_block(u32 *state, u32 *stream)
+void chacha20_block(u32 *state, u8 *stream)
{
- u32 x[16], *out = stream;
+ u32 x[16];
int i;
for (i = 0; i < ARRAY_SIZE(x); i++)
@@ -72,7 +72,7 @@ void chacha20_block(u32 *state, u32 *str
}
for (i = 0; i < ARRAY_SIZE(x); i++)
- out[i] = cpu_to_le32(x[i] + state[i]);
+ put_unaligned_le32(x[i] + state[i], &stream[i * sizeof(u32)]);
state[12]++;
}
Patches currently in stable-queue which might be from ebiggers@xxxxxxxxxx are
queue-4.14/random-do-not-take-pool-spinlock-at-boot.patch
queue-4.14/random-introduce-drain_entropy-helper-to-declutter-crng_reseed.patch
queue-4.14/random-fix-locking-in-crng_fast_load.patch
queue-4.14/random-group-userspace-read-write-functions.patch
queue-4.14/random-make-credit_entropy_bits-always-safe.patch
queue-4.14/crypto-chacha20-fix-chacha20_block-keystream-alignment-again.patch
queue-4.14/random-pull-add_hwgenerator_randomness-declaration-into-random.h.patch
queue-4.14/random-unify-early-init-crng-load-accounting.patch
queue-4.14/random-use-blake2s-instead-of-sha1-in-extraction.patch
queue-4.14/random-initialize-chacha20-constants-with-correct-endianness.patch
queue-4.14/random-group-entropy-extraction-functions.patch
queue-4.14/random-rewrite-header-introductory-comment.patch
queue-4.14/random-remove-ifdef-d-out-interrupt-bench.patch
queue-4.14/random-tie-batched-entropy-generation-to-base_crng-generation.patch
queue-4.14/random-use-linear-min-entropy-accumulation-crediting.patch
queue-4.14/random-remove-batched-entropy-locking.patch
queue-4.14/random-inline-leaves-of-rand_initialize.patch
queue-4.14/random-remove-use_input_pool-parameter-from-crng_reseed.patch
queue-4.14/random-zero-buffer-after-reading-entropy-from-userspace.patch
queue-4.14/random-remove-whitespace-and-reorder-includes.patch
queue-4.14/random-simplify-entropy-debiting.patch
queue-4.14/random-document-crng_fast_key_erasure-destination-possibility.patch
queue-4.14/random-absorb-fast-pool-into-input-pool-after-fast-load.patch
queue-4.14/random-use-rdseed-instead-of-rdrand-in-entropy-extraction.patch
queue-4.14/random-remove-dead-code-left-over-from-blocking-pool.patch
queue-4.14/random-use-computational-hash-for-entropy-extraction.patch
queue-4.14/random-always-wake-up-entropy-writers-after-extraction.patch
queue-4.14/random-do-not-xor-rdrand-when-writing-into-dev-random.patch
queue-4.14/random-group-initialization-wait-functions.patch
queue-4.14/random-remove-unused-tracepoints.patch
queue-4.14/crypto-chacha20-fix-keystream-alignment-for-chacha20_block.patch
queue-4.14/random-check-for-crng_init-0-in-add_device_randomness.patch
queue-4.14/crypto-blake2s-include-linux-bug.h-instead-of-asm-bug.h.patch
queue-4.14/random-group-entropy-collection-functions.patch
queue-4.14/random-remove-useless-header-comment.patch
queue-4.14/random-remove-outdated-int_max-6-check-in-urandom_read.patch
queue-4.14/random-do-not-pretend-to-handle-premature-next-security-model.patch
queue-4.14/random-avoid-arch_get_random_seed_long-when-collecting-irq-randomness.patch
queue-4.14/random-reseed-more-often-immediately-after-booting.patch
queue-4.14/random-ensure-early-rdseed-goes-through-mixer-on-init.patch
queue-4.14/crypto-blake2s-adjust-include-guard-naming.patch
queue-4.14/random-use-hash-function-for-crng_slow_load.patch
