From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Cc: <lists@xxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Andy Grover <agrover@xxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/iscsi/iscsi_target.c | 10 ++++++----
drivers/target/iscsi/iscsi_target_core.h | 1 -
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 6a95f3d..e2f3944 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1038,6 +1038,8 @@ done:
*/
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,
@@ -2507,10 +2509,10 @@ 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);
@@ -3012,10 +3014,10 @@ 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;
diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index 3723d90..0e96a6b 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -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 */
--
1.7.2.5
--
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