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>
This commit is contained in:
Nicholas Bellinger 2011-11-15 23:59:00 -08:00
parent fef58a6096
commit 7e46cf0268
2 changed files with 6 additions and 5 deletions

View File

@ -1039,6 +1039,8 @@ static int iscsit_handle_scsi_cmd(
*/
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 @@ static int iscsit_send_data_in(
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 @@ static int iscsit_send_status(
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;

View File

@ -398,7 +398,6 @@ struct iscsi_cmd {
u32 pdu_send_order;
/* Current struct iscsi_pdu in struct iscsi_cmd->pdu_list */
u32 pdu_start;
u32 residual_count;
/* Next struct iscsi_seq to send in struct iscsi_cmd->seq_list */
u32 seq_send_order;
/* Number of struct iscsi_seq in struct iscsi_cmd->seq_list */