(target mode)
struct atio7_fcp_cmnd is a variable-length data structure because of
add_cdb_len, but it is embedded in struct atio_from_isp and copied
around like a fixed-length data structure. For big CDBs > 16 bytes,
get_datalen_for_atio() called on a fixed-length copy of the atio will
access invalid memory.
In some cases this can be fixed by moving the atio to the end of the
data structure and using a variable-length allocation. In other cases
such as allocating struct qla_tgt_cmd, the fixed-length data structures
are preallocated for speed, so in the case that add_cdb_len != 0,
allocate a separate buffer for the CDB. Also add memcpy_atio() as a
safeguard against invalid memory accesses.
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
---
drivers/scsi/qla2xxx/qla_target.c | 83 ++++++++++++++++++++++++++++---
drivers/scsi/qla2xxx/qla_target.h | 7 ++-
2 files changed, 81 insertions(+), 9 deletions(-)
diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index 7c278f92ff3b..eabb891a5528 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -210,6 +210,10 @@ static void qlt_queue_unknown_atio(scsi_qla_host_t *vha,
struct qla_tgt_sess_op *u;
struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
unsigned long flags;
+ unsigned int add_cdb_len = 0;
+
+ /* atio must be the last member of qla_tgt_sess_op for add_cdb_len */
+ BUILD_BUG_ON(offsetof(struct qla_tgt_sess_op, atio) + sizeof(u->atio) != sizeof(*u));
if (tgt->tgt_stop) {
ql_dbg(ql_dbg_async, vha, 0x502c,
@@ -218,12 +222,17 @@ static void qlt_queue_unknown_atio(scsi_qla_host_t *vha,
goto out_term;
}
- u = kzalloc(sizeof(*u), GFP_ATOMIC);
+ if (atio->u.raw.entry_type == ATIO_TYPE7 &&
+ atio->u.isp24.fcp_cmnd.task_mgmt_flags == 0)
+ add_cdb_len =
+ ((unsigned int) atio->u.isp24.fcp_cmnd.add_cdb_len) * 4;
+
+ u = kzalloc(sizeof(*u) + add_cdb_len, GFP_ATOMIC);
if (u == NULL)
goto out_term;
u->vha = vha;
- memcpy(&u->atio, atio, sizeof(*atio));
+ memcpy(&u->atio, atio, sizeof(*atio) + add_cdb_len);
INIT_LIST_HEAD(&u->cmd_list);
spin_lock_irqsave(&vha->cmd_list_lock, flags);
@@ -3821,6 +3830,13 @@ void qlt_free_cmd(struct qla_tgt_cmd *cmd)
qlt_decr_num_pend_cmds(cmd->vha);
BUG_ON(cmd->sg_mapped);
+
+ if (unlikely(cmd->cdb != &cmd->atio.u.isp24.fcp_cmnd.cdb[0])) {
+ kfree(cmd->cdb);
+ cmd->cdb = &cmd->atio.u.isp24.fcp_cmnd.cdb[0];
+ cmd->cdb_len = 16;
+ }
+
cmd->jiffies_at_free = get_jiffies_64();
if (!sess || !sess->se_sess) {
@@ -4120,7 +4136,6 @@ static void __qlt_do_work(struct qla_tgt_cmd *cmd)
struct qla_hw_data *ha = vha->hw;
struct fc_port *sess = cmd->sess;
struct atio_from_isp *atio = &cmd->atio;
- unsigned char *cdb;
unsigned long flags;
uint32_t data_length;
int ret, fcp_task_attr, data_dir, bidi = 0;
@@ -4136,7 +4151,6 @@ static void __qlt_do_work(struct qla_tgt_cmd *cmd)
goto out_term;
}
- cdb = &atio->u.isp24.fcp_cmnd.cdb[0];
cmd->se_cmd.tag = le32_to_cpu(atio->u.isp24.exchange_addr);
if (atio->u.isp24.fcp_cmnd.rddata &&
@@ -4154,7 +4168,7 @@ static void __qlt_do_work(struct qla_tgt_cmd *cmd)
atio->u.isp24.fcp_cmnd.task_attr);
data_length = get_datalen_for_atio(atio);
- ret = ha->tgt.tgt_ops->handle_cmd(vha, cmd, cdb, data_length,
+ ret = ha->tgt.tgt_ops->handle_cmd(vha, cmd, cmd->cdb, data_length,
fcp_task_attr, data_dir, bidi);
if (ret != 0)
goto out_term;
@@ -4175,6 +4189,11 @@ static void __qlt_do_work(struct qla_tgt_cmd *cmd)
qlt_send_term_exchange(qpair, NULL, &cmd->atio, 1);
qlt_decr_num_pend_cmds(vha);
+ if (unlikely(cmd->cdb != &cmd->atio.u.isp24.fcp_cmnd.cdb[0])) {
+ kfree(cmd->cdb);
+ cmd->cdb = &cmd->atio.u.isp24.fcp_cmnd.cdb[0];
+ cmd->cdb_len = 16;
+ }
cmd->vha->hw->tgt.tgt_ops->rel_cmd(cmd);
spin_unlock_irqrestore(qpair->qp_lock_ptr, flags);
@@ -4298,18 +4317,43 @@ static void qlt_assign_qpair(struct scsi_qla_host *vha,
cmd->se_cmd.cpuid = h->cpuid;
}
+/*
+ * Safely make a fixed-length copy of a variable-length atio by truncating the
+ * CDB if necessary.
+ */
+static void memcpy_atio(struct atio_from_isp *dst,
+ const struct atio_from_isp *src)
+{
+ int len;
+
+ memcpy(dst, src, sizeof(*dst));
+
+ /*
+ * If the CDB was truncated, prevent get_datalen_for_atio() from
+ * accessing invalid memory.
+ */
+ len = src->u.isp24.fcp_cmnd.add_cdb_len;
+ if (unlikely(len != 0)) {
+ dst->u.isp24.fcp_cmnd.add_cdb_len = 0;
+ memcpy(&dst->u.isp24.fcp_cmnd.add_cdb[0],
+ &src->u.isp24.fcp_cmnd.add_cdb[len * 4],
+ 4);
+ }
+}
+
static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t *vha,
struct fc_port *sess,
struct atio_from_isp *atio)
{
struct qla_tgt_cmd *cmd;
+ int add_cdb_len;
cmd = vha->hw->tgt.tgt_ops->get_cmd(sess);
if (!cmd)
return NULL;
cmd->cmd_type = TYPE_TGT_CMD;
- memcpy(&cmd->atio, atio, sizeof(*atio));
+ memcpy_atio(&cmd->atio, atio);
INIT_LIST_HEAD(&cmd->sess_cmd_list);
cmd->state = QLA_TGT_STATE_NEW;
cmd->tgt = vha->vha_tgt.qla_tgt;
@@ -4329,6 +4373,29 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t *vha,
cmd->vp_idx = vha->vp_idx;
cmd->edif = sess->edif.enable;
+ cmd->cdb = &cmd->atio.u.isp24.fcp_cmnd.cdb[0];
+ cmd->cdb_len = 16;
+
+ /*
+ * NOTE: memcpy_atio() set cmd->atio.u.isp24.fcp_cmnd.add_cdb_len to 0,
+ * so use the original value here.
+ */
+ add_cdb_len = atio->u.isp24.fcp_cmnd.add_cdb_len;
+ if (unlikely(add_cdb_len != 0)) {
+ int cdb_len = 16 + add_cdb_len * 4;
+ u8 *cdb;
+
+ cdb = kmalloc(cdb_len, GFP_ATOMIC);
+ if (unlikely(!cdb)) {
+ vha->hw->tgt.tgt_ops->free_cmd(cmd);
+ return NULL;
+ }
+ /* CAUTION: copy CDB from atio not cmd->atio */
+ memcpy(cdb, atio->u.isp24.fcp_cmnd.cdb, cdb_len);
+ cmd->cdb = cdb;
+ cmd->cdb_len = cdb_len;
+ }
+
return cmd;
}
@@ -5476,13 +5543,15 @@ qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
qlt_incr_num_pend_cmds(vha);
INIT_LIST_HEAD(&cmd->cmd_list);
- memcpy(&cmd->atio, atio, sizeof(*atio));
+ memcpy_atio(&cmd->atio, atio);
cmd->tgt = vha->vha_tgt.qla_tgt;
cmd->vha = vha;
cmd->reset_count = ha->base_qpair->chip_reset;
cmd->q_full = 1;
cmd->qpair = ha->base_qpair;
+ cmd->cdb = &cmd->atio.u.isp24.fcp_cmnd.cdb[0];
+ cmd->cdb_len = 16;
if (qfull) {
cmd->q_full = 1;
diff --git a/drivers/scsi/qla2xxx/qla_target.h b/drivers/scsi/qla2xxx/qla_target.h
index adbc2a05b159..1931e1dade7a 100644
--- a/drivers/scsi/qla2xxx/qla_target.h
+++ b/drivers/scsi/qla2xxx/qla_target.h
@@ -830,11 +830,13 @@ struct qla_tgt {
struct qla_tgt_sess_op {
struct scsi_qla_host *vha;
uint32_t chip_reset;
- struct atio_from_isp atio;
struct work_struct work;
struct list_head cmd_list;
bool aborted;
struct rsp_que *rsp;
+
+ struct atio_from_isp atio;
+ /* DO NOT ADD ANYTHING ELSE HERE - atio must be last member */
};
enum trace_flags {
@@ -926,8 +928,9 @@ struct qla_tgt_cmd {
uint8_t scsi_status, sense_key, asc, ascq;
struct crc_context *ctx;
- const uint8_t *cdb;
+ uint8_t *cdb;
uint64_t lba;
+ int cdb_len;
uint16_t a_guard, e_guard, a_app_tag, e_app_tag;
uint32_t a_ref_tag, e_ref_tag;
#define DIF_BUNDL_DMA_VALID 1
--
2.43.0