commit 68279380266a5fa70e664de754503338e2ec3f43 upstream.

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 Link: https://lore.kernel.org/r/20250703172316.7914-1-ebiggers@kernel.org Signed-off-by: Eric Biggers ebiggers@kernel.org --- arch/s390/crypto/sha1_s390.c | 2 ++ arch/s390/crypto/sha256_s390.c | 3 +++ arch/s390/crypto/sha512_s390.c | 3 +++ 3 files changed, 8 insertions(+)

diff --git a/arch/s390/crypto/sha1_s390.c b/arch/s390/crypto/sha1_s390.c index bc3a22704e09..10950953429e 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) @@ -60,10 +61,11 @@ static int s390_sha1_import(struct shash_desc *desc, const void *in)

sctx->count = ictx->count; memcpy(sctx->state, ictx->state, sizeof(ictx->state)); memcpy(sctx->buf, ictx->buffer, sizeof(ictx->buffer)); 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/sha256_s390.c b/arch/s390/crypto/sha256_s390.c index 6f1ccdf93d3e..0204d4bca340 100644 --- a/arch/s390/crypto/sha256_s390.c +++ b/arch/s390/crypto/sha256_s390.c @@ -29,10 +29,11 @@ static int s390_sha256_init(struct shash_desc *desc) sctx->state[5] = SHA256_H5; sctx->state[6] = SHA256_H6; sctx->state[7] = SHA256_H7; sctx->count = 0; sctx->func = CPACF_KIMD_SHA_256; + sctx->first_message_part = 0;

return 0; }

static int sha256_export(struct shash_desc *desc, void *out) @@ -53,10 +54,11 @@ static int sha256_import(struct shash_desc *desc, const void *in)

sctx->count = ictx->count; memcpy(sctx->state, ictx->state, sizeof(ictx->state)); memcpy(sctx->buf, ictx->buf, sizeof(ictx->buf)); sctx->func = CPACF_KIMD_SHA_256; + sctx->first_message_part = 0; return 0; }

static struct shash_alg sha256_alg = { .digestsize = SHA256_DIGEST_SIZE, @@ -88,10 +90,11 @@ static int s390_sha224_init(struct shash_desc *desc) sctx->state[5] = SHA224_H5; sctx->state[6] = SHA224_H6; sctx->state[7] = SHA224_H7; sctx->count = 0; sctx->func = CPACF_KIMD_SHA_256; + sctx->first_message_part = 0;

return 0; }

static struct shash_alg sha224_alg = { diff --git a/arch/s390/crypto/sha512_s390.c b/arch/s390/crypto/sha512_s390.c index 04f11c407763..b53a7793bd24 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) *(__u64 *)&ctx->state[10] = SHA512_H5; *(__u64 *)&ctx->state[12] = SHA512_H6; *(__u64 *)&ctx->state[14] = SHA512_H7; ctx->count = 0; ctx->func = CPACF_KIMD_SHA_512; + ctx->first_message_part = 0;

return 0; }

static int sha512_export(struct shash_desc *desc, void *out) @@ -58,10 +59,11 @@ static int sha512_import(struct shash_desc *desc, const void *in) sctx->count = ictx->count[0];

memcpy(sctx->state, ictx->state, sizeof(ictx->state)); memcpy(sctx->buf, ictx->buf, sizeof(ictx->buf)); 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) *(__u64 *)&ctx->state[10] = SHA384_H5; *(__u64 *)&ctx->state[12] = SHA384_H6; *(__u64 *)&ctx->state[14] = SHA384_H7; ctx->count = 0; ctx->func = CPACF_KIMD_SHA_512; + ctx->first_message_part = 0;

return 0; }

static struct shash_alg sha384_alg = {

base-commit: 7b59ab988c01c190f1b528cf750d6f33b738d1e2