iscsi-target: Fix residual count hanlding + remove iscsi_cmd->residual_count
This patch fixes iscsi-target handling of underflow where residual data is
causing an OOPs by using the incorrect iscsi_cmd_t->data_length initially
assigned in iscsit_allocate_se_cmd(). It resets iscsi_cmd_t->data_length
from se_cmd_t->data_length after transport_generic_allocate_tasks()
has been invoked in iscsit_handle_scsi_cmd() RX context, and converts
iscsi_cmd->residual_count usage to access iscsi_cmd->se_cmd.residual_count
to get the proper residual count set by target-core.
Reported-by: <lists@internyc.net>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 4d81e10..26834ef 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1039,6 +1039,8 @@
*/
send_check_condition = 1;
} else {
+ cmd->data_length = cmd->se_cmd.data_length;
+
if (iscsit_decide_list_to_build(cmd, payload_length) < 0)
return iscsit_add_reject_from_cmd(
ISCSI_REASON_BOOKMARK_NO_RESOURCES,
@@ -2508,10 +2510,10 @@
if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
hdr->flags |= ISCSI_FLAG_DATA_OVERFLOW;
- hdr->residual_count = cpu_to_be32(cmd->residual_count);
+ hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
hdr->flags |= ISCSI_FLAG_DATA_UNDERFLOW;
- hdr->residual_count = cpu_to_be32(cmd->residual_count);
+ hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
}
}
hton24(hdr->dlength, datain.length);
@@ -3013,10 +3015,10 @@
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
hdr->flags |= ISCSI_FLAG_CMD_OVERFLOW;
- hdr->residual_count = cpu_to_be32(cmd->residual_count);
+ hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
hdr->flags |= ISCSI_FLAG_CMD_UNDERFLOW;
- hdr->residual_count = cpu_to_be32(cmd->residual_count);
+ hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
}
hdr->response = cmd->iscsi_response;
hdr->cmd_status = cmd->se_cmd.scsi_status;