From: Harald Freudenberger Date: Mon, 3 Aug 2026 08:33:34 +0000 (+0200) Subject: s390/zcrypt: Fix CPRB memory allocation in zcrypt misc code X-Git-Tag: v7.2-rc7~2^2~4 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5004889551dfaf7f4b2cda8ed213d234bb8ebf82;p=thirdparty%2Flinux.git s390/zcrypt: Fix CPRB memory allocation in zcrypt misc code Both CPRB alloc functions in zcrypt_ccamisc.c and zcrypt_ep11misc.c did not round up the memory allocation to a multiple of 4 bytes as it is needed by the zcrypt layer to process the CPRBs. Now the alloc_and_prep_cprbmem() and alloc_cprbmem() functions guarantee that the base CPRB struct and a possible parameter block are aligned to a 4-byte boundary and the backing memory allocation is rounded up to the next multiple of 4 byte. Also the free_cprbmem() is updated and scrubs the rounded up amount of memory. Fixes: 9bdb5f7e8369 ("s390/zcrypt: Introduce cprb mempool for cca misc functions") Signed-off-by: Harald Freudenberger Reviewed-by: Holger Dengler Cc: stable@vger.kernel.org # 6.16+ Signed-off-by: Vasily Gorbik --- diff --git a/drivers/s390/crypto/zcrypt_ccamisc.c b/drivers/s390/crypto/zcrypt_ccamisc.c index 86d2ee78c9f4..d4ce6352b5b2 100644 --- a/drivers/s390/crypto/zcrypt_ccamisc.c +++ b/drivers/s390/crypto/zcrypt_ccamisc.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -267,6 +268,10 @@ EXPORT_SYMBOL(cca_check_sececckeytoken); * block, reply CPRB and reply param block and fill in values * for the common fields. Returns 0 on success or errno value * on failure. + * It is guaranteed that request and a possible param block + * are aligned to a 4 byte boundary. Furthermore if a param + * block is used, the memory allocated for this is rounded up to + * the next multiple of 4 bytes. */ static int alloc_and_prep_cprbmem(size_t paramblen, u8 **p_cprb_mem, @@ -275,7 +280,8 @@ static int alloc_and_prep_cprbmem(size_t paramblen, u32 xflags) { u8 *cprbmem = NULL; - size_t cprbplusparamblen = sizeof(struct CPRBX) + paramblen; + size_t cprbplusparamblen = + ALIGN(sizeof(struct CPRBX), 4) + ALIGN(paramblen, 4); size_t len = 2 * cprbplusparamblen; struct CPRBX *preqcblk, *prepcblk; @@ -302,10 +308,10 @@ static int alloc_and_prep_cprbmem(size_t paramblen, memcpy(preqcblk->func_id, "T2", 2); preqcblk->rpl_msgbl = cprbplusparamblen; if (paramblen) { - preqcblk->req_parmb = - ((u8 __user *)preqcblk) + sizeof(struct CPRBX); - preqcblk->rpl_parmb = - ((u8 __user *)prepcblk) + sizeof(struct CPRBX); + preqcblk->req_parmb = ((u8 __user *)preqcblk) + + ALIGN(sizeof(struct CPRBX), 4); + preqcblk->rpl_parmb = ((u8 __user *)prepcblk) + + ALIGN(sizeof(struct CPRBX), 4); } *p_cprb_mem = cprbmem; @@ -323,8 +329,10 @@ static int alloc_and_prep_cprbmem(size_t paramblen, */ static void free_cprbmem(void *mem, size_t paramblen, bool scrub, u32 xflags) { + size_t cprblen = ALIGN(sizeof(struct CPRBX), 4) + ALIGN(paramblen, 4); + if (mem && scrub) - memzero_explicit(mem, 2 * (sizeof(struct CPRBX) + paramblen)); + memzero_explicit(mem, 2 * cprblen); if (xflags & ZCRYPT_XFLAG_NOMEMALLOC) mempool_free(mem, cprb_mempool); diff --git a/drivers/s390/crypto/zcrypt_ep11misc.c b/drivers/s390/crypto/zcrypt_ep11misc.c index 3dda9589f2b9..2d900ffc5068 100644 --- a/drivers/s390/crypto/zcrypt_ep11misc.c +++ b/drivers/s390/crypto/zcrypt_ep11misc.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -355,21 +356,24 @@ EXPORT_SYMBOL(ep11_check_aes_key); /* * Allocate and prepare ep11 cprb plus additional payload. + * It is guaranteed that the memory is aligned to a 4 byte boundary. + * Furthermore the memory allocation is rounded up to the next + * multiple of 4 bytes (with taking the payload_len into account). */ static void *alloc_cprbmem(size_t payload_len, u32 xflags) { - size_t len = sizeof(struct ep11_cprb) + payload_len; + size_t memlen = ALIGN(sizeof(struct ep11_cprb) + payload_len, 4); struct ep11_cprb *cprb = NULL; if (xflags & ZCRYPT_XFLAG_NOMEMALLOC) { - if (len <= CPRB_MEMPOOL_ITEM_SIZE) + if (memlen <= CPRB_MEMPOOL_ITEM_SIZE) cprb = mempool_alloc_preallocated(cprb_mempool); } else { - cprb = kmalloc(len, GFP_KERNEL); + cprb = kmalloc(memlen, GFP_KERNEL); } if (!cprb) return NULL; - memset(cprb, 0, len); + memset(cprb, 0, memlen); cprb->cprb_len = sizeof(struct ep11_cprb); cprb->cprb_ver_id = 0x04; @@ -385,8 +389,10 @@ static void *alloc_cprbmem(size_t payload_len, u32 xflags) */ static void free_cprbmem(void *mem, size_t payload_len, bool scrub, u32 xflags) { + size_t memlen = ALIGN(sizeof(struct ep11_cprb) + payload_len, 4); + if (mem && scrub) - memzero_explicit(mem, sizeof(struct ep11_cprb) + payload_len); + memzero_explicit(mem, memlen); if (xflags & ZCRYPT_XFLAG_NOMEMALLOC) mempool_free(mem, cprb_mempool);