In newer version of the SBC specs, we have a NDOB bit that indicates there
is no data buffer that gets written out. If this bit is set using commands
like "sg_write_same --ndob" we will crash in target_core_iblock/file's
execute_write_same handlers when we go to access the se_cmd->t_data_sg
because its NULL.
This patch adds a check for the NDOB bit in the common WRITE SAME code
because we don't support it. And, it adds a check for zero SG elements in
each handler in case the initiator tries to send a normal WRITE SAME with
no data buffer.
Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
---
drivers/target/target_core_file.c | 3 +++
drivers/target/target_core_iblock.c | 4 ++++
drivers/target/target_core_sbc.c | 6 ++++++
3 files changed, 13 insertions(+)
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index e68f1cc8ef98..6c8d8b051bfd 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -448,6 +448,9 @@ fd_execute_write_same(struct se_cmd *cmd)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
+ if (!cmd->t_data_nents)
+ return TCM_INVALID_CDB_FIELD;
+
if (cmd->t_data_nents > 1 ||
cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 378c80313a0f..1ed9381751e6 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -494,6 +494,10 @@ iblock_execute_write_same(struct se_cmd *cmd)
" backends not supported\n");
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
+
+ if (!cmd->t_data_nents)
+ return TCM_INVALID_CDB_FIELD;
+
sg = &cmd->t_data_sg[0];
if (cmd->t_data_nents > 1 ||
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index ca1b2312d6e7..f6132836eb38 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -312,6 +312,12 @@ sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *op
pr_warn("WRITE SAME with ANCHOR not supported\n");
return TCM_INVALID_CDB_FIELD;
}
+
+ if (flags & 0x01) {
+ pr_warn("WRITE SAME with NDOB not supported\n");
+ return TCM_INVALID_CDB_FIELD;
+ }
+
/*
* Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
* translated into block discard requests within backend code.
--
2.25.1
