From: Harald Freudenberger Date: Thu, 23 Jul 2026 09:54:53 +0000 (+0200) Subject: s390/zcrypt: Close speculative mem read possibility X-Git-Tag: v7.2-rc6~2^2~1 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e935cd525af4c6ed2e2c6404aa27ca19c7f39ddb;p=thirdparty%2Flinux.git s390/zcrypt: Close speculative mem read possibility The domain value is extracted from a given CCA or EP11 ioctl struct when a CPRB is about to be sent. Thus this is a user controlled value. Under some special conditions (custom device node used, administrative load) this value is used as an array index after bounds checking, but without speculation barrier. Add the missing array_index_nospec() call to prevent speculative execution where this domain value is used. Fixes: cfd68b33094e ("s390/zcrypt: Filter admin CPRBs on custom devices") Cc: stable@vger.kernel.org Reported-by: Christian Borntraeger Reviewed-by: Finn Callies Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik --- diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c index 81eefdeae248..ec6a4c2f9f04 100644 --- a/drivers/s390/crypto/zcrypt_api.c +++ b/drivers/s390/crypto/zcrypt_api.c @@ -879,6 +879,7 @@ static long _zcrypt_send_cprb(u32 xflags, struct ap_perms *perms, if (perms != &ap_perms && domain < AP_DOMAINS) { if (ap_msg.flags & AP_MSG_FLAG_ADMIN) { + domain = array_index_nospec(domain, AP_DOMAINS); if (!test_bit_inv(domain, perms->adm)) { rc = -ENODEV; goto out; @@ -1079,6 +1080,7 @@ static long _zcrypt_send_ep11_cprb(u32 xflags, struct ap_perms *perms, if (perms != &ap_perms && domain < AP_DOMAINS) { if (ap_msg.flags & AP_MSG_FLAG_ADMIN) { + domain = array_index_nospec(domain, AP_DOMAINS); if (!test_bit_inv(domain, perms->adm)) { rc = -ENODEV; goto out;