This is a note to let you know that I've just added the patch titled
crypto: arm64/sm4-gcm - Fix possible crash in GCM cryption
to the 6.2-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-arm64-sm4-gcm-fix-possible-crash-in-gcm-cryption.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4e4a08868f15897ca236528771c3733fded42c62 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Date: Thu, 2 Feb 2023 16:33:47 +0800
Subject: crypto: arm64/sm4-gcm - Fix possible crash in GCM cryption
From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
commit 4e4a08868f15897ca236528771c3733fded42c62 upstream.
An often overlooked aspect of the skcipher walker API is that an
error is not just indicated by a non-zero return value, but by the
fact that walk->nbytes is zero.
Thus it is an error to call skcipher_walk_done after getting back
walk->nbytes == 0 from the previous interaction with the walker.
This is because when walk->nbytes is zero the walker is left in
an undefined state and any further calls to it may try to free
uninitialised stack memory.
The sm4 arm64 ccm code gets this wrong and ends up calling
skcipher_walk_done even when walk->nbytes is zero.
This patch rewrites the loop in a form that resembles other callers.
Reported-by: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx>
Fixes: ae1b83c7d572 ("crypto: arm64/sm4 - add CE implementation for GCM mode")
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Tested-by: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/crypto/sm4-ce-gcm-glue.c | 51 +++++++++++++++++-------------------
1 file changed, 25 insertions(+), 26 deletions(-)
--- a/arch/arm64/crypto/sm4-ce-gcm-glue.c
+++ b/arch/arm64/crypto/sm4-ce-gcm-glue.c
@@ -135,22 +135,23 @@ static void gcm_calculate_auth_mac(struc
}
static int gcm_crypt(struct aead_request *req, struct skcipher_walk *walk,
- struct sm4_gcm_ctx *ctx, u8 ghash[],
+ u8 ghash[], int err,
void (*sm4_ce_pmull_gcm_crypt)(const u32 *rkey_enc,
u8 *dst, const u8 *src, u8 *iv,
unsigned int nbytes, u8 *ghash,
const u8 *ghash_table, const u8 *lengths))
{
+ struct crypto_aead *aead = crypto_aead_reqtfm(req);
+ struct sm4_gcm_ctx *ctx = crypto_aead_ctx(aead);
u8 __aligned(8) iv[SM4_BLOCK_SIZE];
be128 __aligned(8) lengths;
- int err;
memset(ghash, 0, SM4_BLOCK_SIZE);
lengths.a = cpu_to_be64(req->assoclen * 8);
lengths.b = cpu_to_be64(walk->total * 8);
- memcpy(iv, walk->iv, GCM_IV_SIZE);
+ memcpy(iv, req->iv, GCM_IV_SIZE);
put_unaligned_be32(2, iv + GCM_IV_SIZE);
kernel_neon_begin();
@@ -158,49 +159,51 @@ static int gcm_crypt(struct aead_request
if (req->assoclen)
gcm_calculate_auth_mac(req, ghash);
- do {
+ while (walk->nbytes) {
unsigned int tail = walk->nbytes % SM4_BLOCK_SIZE;
const u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
if (walk->nbytes == walk->total) {
- tail = 0;
-
sm4_ce_pmull_gcm_crypt(ctx->key.rkey_enc, dst, src, iv,
walk->nbytes, ghash,
ctx->ghash_table,
(const u8 *)&lengths);
- } else if (walk->nbytes - tail) {
- sm4_ce_pmull_gcm_crypt(ctx->key.rkey_enc, dst, src, iv,
- walk->nbytes - tail, ghash,
- ctx->ghash_table, NULL);
+
+ kernel_neon_end();
+
+ return skcipher_walk_done(walk, 0);
}
+ sm4_ce_pmull_gcm_crypt(ctx->key.rkey_enc, dst, src, iv,
+ walk->nbytes - tail, ghash,
+ ctx->ghash_table, NULL);
+
kernel_neon_end();
err = skcipher_walk_done(walk, tail);
- if (err)
- return err;
- if (walk->nbytes)
- kernel_neon_begin();
- } while (walk->nbytes > 0);
- return 0;
+ kernel_neon_begin();
+ }
+
+ sm4_ce_pmull_gcm_crypt(ctx->key.rkey_enc, NULL, NULL, iv,
+ walk->nbytes, ghash, ctx->ghash_table,
+ (const u8 *)&lengths);
+
+ kernel_neon_end();
+
+ return err;
}
static int gcm_encrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
- struct sm4_gcm_ctx *ctx = crypto_aead_ctx(aead);
u8 __aligned(8) ghash[SM4_BLOCK_SIZE];
struct skcipher_walk walk;
int err;
err = skcipher_walk_aead_encrypt(&walk, req, false);
- if (err)
- return err;
-
- err = gcm_crypt(req, &walk, ctx, ghash, sm4_ce_pmull_gcm_enc);
+ err = gcm_crypt(req, &walk, ghash, err, sm4_ce_pmull_gcm_enc);
if (err)
return err;
@@ -215,17 +218,13 @@ static int gcm_decrypt(struct aead_reque
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
unsigned int authsize = crypto_aead_authsize(aead);
- struct sm4_gcm_ctx *ctx = crypto_aead_ctx(aead);
u8 __aligned(8) ghash[SM4_BLOCK_SIZE];
u8 authtag[SM4_BLOCK_SIZE];
struct skcipher_walk walk;
int err;
err = skcipher_walk_aead_decrypt(&walk, req, false);
- if (err)
- return err;
-
- err = gcm_crypt(req, &walk, ctx, ghash, sm4_ce_pmull_gcm_dec);
+ err = gcm_crypt(req, &walk, ghash, err, sm4_ce_pmull_gcm_dec);
if (err)
return err;
Patches currently in stable-queue which might be from herbert@xxxxxxxxxxxxxxxxxxx are
queue-6.2/crypto-arm64-sm4-gcm-fix-possible-crash-in-gcm-cryption.patch
