From: Roland Dreier Date: Tue, 14 Oct 2014 21:16:24 +0000 (-0700) Subject: target: Don't call TFO->write_pending if data_length == 0 X-Git-Tag: firefly_0821_release~3679^2~1097 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=adbde413d06062edf380d4aad15caf32492e4872;p=firefly-linux-kernel-4.4.55.git 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 --- diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 12342695ed79..dcc5daa0ff1c 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2128,7 +2128,7 @@ 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; }