From 20a1d763e503d4b54dfebb0d6977d867dadb2103 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Tue, 14 Oct 2014 14:16:24 -0700 Subject: [PATCH] target: Don't call TFO->write_pending if data_length == 0 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 Signed-off-by: Roland Dreier Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- 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 9232c773..e6463ef 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2230,7 +2230,7 @@ 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; } -- 2.7.4