From: Heiko Carstens <heiko.carstens@xxxxxxxxxx> zfcp_erp_strategy_check_fsfreq() checks if it is safe to access the fsf_req associated with the erp_action that gets passed. To test if it is safe it accesses the fsf_req in order to get its index into the hash list. This is broken since the fsf_req might be freed already and the read index has no meaning. It could lead to memory corruption. Fix this by introducing a new zfcp_reqlist_find_safe() method which just checks if addresses are equal. This is slower, but only gets called in case of error recovery. Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Signed-off-by: Swen Schillig <swen@xxxxxxxxxxxx> --- drivers/s390/scsi/zfcp_def.h | 14 ++++++++++++++ drivers/s390/scsi/zfcp_erp.c | 3 ++- 2 files changed, 16 insertions(+), 1 deletion(-) Index: SHIP_OCT2005/drivers/s390/scsi/zfcp_def.h =================================================================== --- SHIP_OCT2005.orig/drivers/s390/scsi/zfcp_def.h +++ SHIP_OCT2005/drivers/s390/scsi/zfcp_def.h @@ -1210,6 +1210,20 @@ zfcp_reqlist_find(struct zfcp_adapter *a return NULL; } +static inline struct zfcp_fsf_req * +zfcp_reqlist_find_safe(struct zfcp_adapter *adapter, struct zfcp_fsf_req *req) +{ + struct zfcp_fsf_req *request; + unsigned int idx; + + for (idx = 0; idx < REQUEST_LIST_SIZE; idx++) { + list_for_each_entry(request, &adapter->req_list[idx], list) + if (request == req) + return request; + } + return NULL; +} + /* * functions needed for reference/usage counting */ Index: SHIP_OCT2005/drivers/s390/scsi/zfcp_erp.c =================================================================== --- SHIP_OCT2005.orig/drivers/s390/scsi/zfcp_erp.c +++ SHIP_OCT2005/drivers/s390/scsi/zfcp_erp.c @@ -837,7 +837,8 @@ zfcp_erp_strategy_check_fsfreq(struct zf if (erp_action->fsf_req) { /* take lock to ensure that request is not deleted meanwhile */ spin_lock(&adapter->req_list_lock); - if (zfcp_reqlist_find(adapter, erp_action->fsf_req->req_id)) { + if (zfcp_reqlist_find_safe(adapter, erp_action->fsf_req) && + erp_action->fsf_req->erp_action == erp_action) { /* fsf_req still exists */ debug_text_event(adapter->erp_dbf, 3, "a_ca_req"); debug_event(adapter->erp_dbf, 3, &erp_action->fsf_req, - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html