Commit 88c02b3f79a6 ("s390/sha3: Support sha3 performance enhancements") added the field s390_sha_ctx::first_message_part and made it be used by s390_sha_update() (now s390_sha_update_blocks()). At the time, s390_sha_update() was used by all the s390 SHA-1, SHA-2, and SHA-3 algorithms. However, only the initialization functions for SHA-3 were updated, leaving SHA-1 and SHA-2 using first_message_part uninitialized.

This could cause e.g. the function code CPACF_KIMD_SHA_512 | CPACF_KIMD_NIP to be used instead of just CPACF_KIMD_SHA_512. This apparently was harmless, as the SHA-1 and SHA-2 function codes ignore CPACF_KIMD_NIP; it is recognized only by the SHA-3 function codes (https://lore.kernel.org/r/73477fe9-a1dc-4e38-98a6-eba9921e8afa@linux.ibm.com...). Therefore, this bug was found only when first_message_part was later converted to a boolean and UBSAN detected its uninitialized use. Regardless, let's fix this by just initializing to zero.

Note: in 6.16, we need to patch SHA-1, SHA-384, and SHA-512. In 6.15 and earlier, we'll also need to patch SHA-224 and SHA-256, as they hadn't yet been librarified (which incidentally fixed this bug).

Fixes: 88c02b3f79a6 ("s390/sha3: Support sha3 performance enhancements") Cc: stable@vger.kernel.org Reported-by: Ingo Franzki ifranzki@linux.ibm.com Closes: https://lore.kernel.org/r/12740696-595c-4604-873e-aefe8b405fbf@linux.ibm.com Acked-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Eric Biggers ebiggers@kernel.org ---

v2: - Also fix s390_sha1_import() and sha512_import() - Use 0 instead of false - Improved commit message

arch/s390/crypto/sha1_s390.c | 2 ++ arch/s390/crypto/sha512_s390.c | 3 +++ 2 files changed, 5 insertions(+)

diff --git a/arch/s390/crypto/sha1_s390.c b/arch/s390/crypto/sha1_s390.c index d229cbd2ba229..9b0d55be12394 100644 --- a/arch/s390/crypto/sha1_s390.c +++ b/arch/s390/crypto/sha1_s390.c @@ -36,10 +36,11 @@ static int s390_sha1_init(struct shash_desc *desc) sctx->state[2] = SHA1_H2; sctx->state[3] = SHA1_H3; sctx->state[4] = SHA1_H4; sctx->count = 0; sctx->func = CPACF_KIMD_SHA_1; + sctx->first_message_part = 0;

return 0; }

static int s390_sha1_export(struct shash_desc *desc, void *out) @@ -58,10 +59,11 @@ static int s390_sha1_import(struct shash_desc *desc, const void *in) const struct sha1_state *ictx = in;

sctx->count = ictx->count; memcpy(sctx->state, ictx->state, sizeof(ictx->state)); sctx->func = CPACF_KIMD_SHA_1; + sctx->first_message_part = 0; return 0; }

static struct shash_alg alg = { .digestsize = SHA1_DIGEST_SIZE, diff --git a/arch/s390/crypto/sha512_s390.c b/arch/s390/crypto/sha512_s390.c index 33711a29618c3..6cbbf5e8555f8 100644 --- a/arch/s390/crypto/sha512_s390.c +++ b/arch/s390/crypto/sha512_s390.c @@ -30,10 +30,11 @@ static int sha512_init(struct shash_desc *desc) ctx->sha512.state[6] = SHA512_H6; ctx->sha512.state[7] = SHA512_H7; ctx->count = 0; ctx->sha512.count_hi = 0; ctx->func = CPACF_KIMD_SHA_512; + ctx->first_message_part = 0;

return 0; }

static int sha512_export(struct shash_desc *desc, void *out) @@ -55,10 +56,11 @@ static int sha512_import(struct shash_desc *desc, const void *in) sctx->count = ictx->count[0]; sctx->sha512.count_hi = ictx->count[1];

memcpy(sctx->state, ictx->state, sizeof(ictx->state)); sctx->func = CPACF_KIMD_SHA_512; + sctx->first_message_part = 0; return 0; }

static struct shash_alg sha512_alg = { .digestsize = SHA512_DIGEST_SIZE, @@ -95,10 +97,11 @@ static int sha384_init(struct shash_desc *desc) ctx->sha512.state[6] = SHA384_H6; ctx->sha512.state[7] = SHA384_H7; ctx->count = 0; ctx->sha512.count_hi = 0; ctx->func = CPACF_KIMD_SHA_512; + ctx->first_message_part = 0;

return 0; }

static struct shash_alg sha384_alg = {

base-commit: 64f7548aad63d2fbca2eeb6eb33361c218ebd5a5