From: Holger Dengler dengler@linux.ibm.com
commit f2ebdadd85af4f4d0cae1e5d009c70eccc78c207 upstream.
Although the clear-key of neither protected- nor secure-keys is accessible, this key material should only be visible to the calling process. So wipe all copies of protected- or secure-keys from stack, even in case of an error.
Reviewed-by: Harald Freudenberger freude@linux.ibm.com Reviewed-by: Ingo Franzki ifranzki@linux.ibm.com Acked-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Holger Dengler dengler@linux.ibm.com Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com [Nikita: small changes were made during cherry-picking due to different debug macro use and similar discrepancies between branches] Signed-off-by: Nikita Zhandarovich n.zhandarovich@fintech.ru --- P.S. As no Fixes: tag was present, I decided against adding it myself and leaving commit body intact.
drivers/s390/crypto/pkey_api.c | 80 ++++++++++++++++------------------ 1 file changed, 37 insertions(+), 43 deletions(-)
diff --git a/drivers/s390/crypto/pkey_api.c b/drivers/s390/crypto/pkey_api.c index 778eddb911fd..754e645c2c71 100644 --- a/drivers/s390/crypto/pkey_api.c +++ b/drivers/s390/crypto/pkey_api.c @@ -1137,10 +1137,9 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, rc = cca_genseckey(kgs.cardnr, kgs.domain, kgs.keytype, kgs.seckey.seckey); DEBUG_DBG("%s cca_genseckey()=%d\n", __func__, rc); - if (rc) - break; - if (copy_to_user(ugs, &kgs, sizeof(kgs))) - return -EFAULT; + if (!rc && copy_to_user(ugs, &kgs, sizeof(kgs))) + rc = -EFAULT; + memzero_explicit(&kgs, sizeof(kgs)); break; } case PKEY_CLR2SECK: { @@ -1167,10 +1166,9 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, ksp.seckey.seckey, ksp.protkey.protkey, &ksp.protkey.len, &ksp.protkey.type); DEBUG_DBG("%s cca_sec2protkey()=%d\n", __func__, rc); - if (rc) - break; - if (copy_to_user(usp, &ksp, sizeof(ksp))) - return -EFAULT; + if (!rc && copy_to_user(usp, &ksp, sizeof(ksp))) + rc = -EFAULT; + memzero_explicit(&ksp, sizeof(ksp)); break; } case PKEY_CLR2PROTK: { @@ -1210,10 +1208,9 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, return -EFAULT; rc = pkey_skey2pkey(ksp.seckey.seckey, &ksp.protkey); DEBUG_DBG("%s pkey_skey2pkey()=%d\n", __func__, rc); - if (rc) - break; - if (copy_to_user(usp, &ksp, sizeof(ksp))) - return -EFAULT; + if (!rc && copy_to_user(usp, &ksp, sizeof(ksp))) + rc = -EFAULT; + memzero_explicit(&ksp, sizeof(ksp)); break; } case PKEY_VERIFYKEY: { @@ -1225,10 +1222,9 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, rc = pkey_verifykey(&kvk.seckey, &kvk.cardnr, &kvk.domain, &kvk.keysize, &kvk.attributes); DEBUG_DBG("%s pkey_verifykey()=%d\n", __func__, rc); - if (rc) - break; - if (copy_to_user(uvk, &kvk, sizeof(kvk))) - return -EFAULT; + if (!rc && copy_to_user(uvk, &kvk, sizeof(kvk))) + rc = -EFAULT; + memzero_explicit(&kvk, sizeof(kvk)); break; } case PKEY_GENPROTK: { @@ -1239,10 +1235,9 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, return -EFAULT; rc = pkey_genprotkey(kgp.keytype, &kgp.protkey); DEBUG_DBG("%s pkey_genprotkey()=%d\n", __func__, rc); - if (rc) - break; - if (copy_to_user(ugp, &kgp, sizeof(kgp))) - return -EFAULT; + if (!rc && copy_to_user(ugp, &kgp, sizeof(kgp))) + rc = -EFAULT; + memzero_explicit(&kgp, sizeof(kgp)); break; } case PKEY_VERIFYPROTK: { @@ -1253,6 +1248,7 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, return -EFAULT; rc = pkey_verifyprotkey(&kvp.protkey); DEBUG_DBG("%s pkey_verifyprotkey()=%d\n", __func__, rc); + memzero_explicit(&kvp, sizeof(kvp)); break; } case PKEY_KBLOB2PROTK: { @@ -1268,10 +1264,9 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, rc = pkey_keyblob2pkey(kkey, ktp.keylen, &ktp.protkey); DEBUG_DBG("%s pkey_keyblob2pkey()=%d\n", __func__, rc); kfree_sensitive(kkey); - if (rc) - break; - if (copy_to_user(utp, &ktp, sizeof(ktp))) - return -EFAULT; + if (!rc && copy_to_user(utp, &ktp, sizeof(ktp))) + rc = -EFAULT; + memzero_explicit(&ktp, sizeof(ktp)); break; } case PKEY_GENSECK2: { @@ -1297,23 +1292,23 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, DEBUG_DBG("%s pkey_genseckey2()=%d\n", __func__, rc); kfree(apqns); if (rc) { - kfree(kkey); + kfree_sensitive(kkey); break; } if (kgs.key) { if (kgs.keylen < klen) { - kfree(kkey); + kfree_sensitive(kkey); return -EINVAL; } if (copy_to_user(kgs.key, kkey, klen)) { - kfree(kkey); + kfree_sensitive(kkey); return -EFAULT; } } kgs.keylen = klen; if (copy_to_user(ugs, &kgs, sizeof(kgs))) rc = -EFAULT; - kfree(kkey); + kfree_sensitive(kkey); break; } case PKEY_CLR2SECK2: { @@ -1341,18 +1336,18 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, DEBUG_DBG("%s pkey_clr2seckey2()=%d\n", __func__, rc); kfree(apqns); if (rc) { - kfree(kkey); + kfree_sensitive(kkey); memzero_explicit(&kcs, sizeof(kcs)); break; } if (kcs.key) { if (kcs.keylen < klen) { - kfree(kkey); + kfree_sensitive(kkey); memzero_explicit(&kcs, sizeof(kcs)); return -EINVAL; } if (copy_to_user(kcs.key, kkey, klen)) { - kfree(kkey); + kfree_sensitive(kkey); memzero_explicit(&kcs, sizeof(kcs)); return -EFAULT; } @@ -1361,7 +1356,7 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, if (copy_to_user(ucs, &kcs, sizeof(kcs))) rc = -EFAULT; memzero_explicit(&kcs, sizeof(kcs)); - kfree(kkey); + kfree_sensitive(kkey); break; } case PKEY_VERIFYKEY2: { @@ -1378,7 +1373,7 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, &kvk.cardnr, &kvk.domain, &kvk.type, &kvk.size, &kvk.flags); DEBUG_DBG("%s pkey_verifykey2()=%d\n", __func__, rc); - kfree(kkey); + kfree_sensitive(kkey); if (rc) break; if (copy_to_user(uvk, &kvk, sizeof(kvk))) @@ -1406,10 +1401,9 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, DEBUG_DBG("%s pkey_keyblob2pkey2()=%d\n", __func__, rc); kfree(apqns); kfree_sensitive(kkey); - if (rc) - break; - if (copy_to_user(utp, &ktp, sizeof(ktp))) - return -EFAULT; + if (!rc && copy_to_user(utp, &ktp, sizeof(ktp))) + rc = -EFAULT; + memzero_explicit(&ktp, sizeof(ktp)); break; } case PKEY_APQNS4K: { @@ -1437,7 +1431,7 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, rc = pkey_apqns4key(kkey, kak.keylen, kak.flags, apqns, &nr_apqns); DEBUG_DBG("%s pkey_apqns4key()=%d\n", __func__, rc); - kfree(kkey); + kfree_sensitive(kkey); if (rc && rc != -ENOSPC) { kfree(apqns); break; @@ -1523,7 +1517,7 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, protkey = kmalloc(protkeylen, GFP_KERNEL); if (!protkey) { kfree(apqns); - kfree(kkey); + kfree_sensitive(kkey); return -ENOMEM; } rc = pkey_keyblob2pkey3(apqns, ktp.apqn_entries, kkey, @@ -1533,20 +1527,20 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd, kfree(apqns); kfree_sensitive(kkey); if (rc) { - kfree(protkey); + kfree_sensitive(protkey); break; } if (ktp.pkey && ktp.pkeylen) { if (protkeylen > ktp.pkeylen) { - kfree(protkey); + kfree_sensitive(protkey); return -EINVAL; } if (copy_to_user(ktp.pkey, protkey, protkeylen)) { - kfree(protkey); + kfree_sensitive(protkey); return -EFAULT; } } - kfree(protkey); + kfree_sensitive(protkey); ktp.pkeylen = protkeylen; if (copy_to_user(utp, &ktp, sizeof(ktp))) return -EFAULT;