[PATCH 3.13.y-ckt 090/121] target: Don't call TFO->write_pending if data_length == 0
Kamal Mostafa
kamal at canonical.com
Tue Dec 2 19:19:29 UTC 2014
3.13.11-ckt12 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Roland Dreier <roland at purestorage.com>
commit 885e7b0e181c14e4d0ddd26c688bad2b84c1ada9 upstream.
If an initiator sends a zero-length command (e.g. TEST UNIT READY) but
sets the transfer direction in the transport layer to indicate a
data-out phase, we still shouldn't try to transfer data. At best it's
a NOP, and depending on the transport, we might crash on an
uninitialized sg list.
Reported-by: Craig Watson <craig.watson at vanguard-rugged.com>
Signed-off-by: Roland Dreier <roland at purestorage.com>
Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
drivers/target/target_core_transport.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 3acb125..40f171b 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2192,7 +2192,7 @@ transport_generic_new_cmd(struct se_cmd *cmd)
* and let it call back once the write buffers are ready.
*/
target_add_to_state_list(cmd);
- if (cmd->data_direction != DMA_TO_DEVICE) {
+ if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
target_execute_cmd(cmd);
return 0;
}
--
1.9.1
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