[PATCH 4.9 08/41] iscsi-target: fix memory leak in iscsit_setup_text_cmd()

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Varun Prakash <varun@xxxxxxxxxxx>

commit ea8dc5b4cd2195ee582cae28afa4164c6dea1738 upstream.

On receiving text request iscsi-target allocates buffer for
payload in iscsit_handle_text_cmd() and assigns buffer pointer
to cmd->text_in_ptr, this buffer is currently freed in
iscsit_release_cmd(), if iscsi-target sets 'C' bit in text
response then it will receive another text request from the
initiator with ttt != 0xffffffff in this case iscsi-target
will find cmd using itt and call iscsit_setup_text_cmd()
which will set cmd->text_in_ptr to NULL without freeing
previously allocated buffer.

This patch fixes this issue by calling kfree(cmd->text_in_ptr)
in iscsit_setup_text_cmd() before assigning NULL to it.

For the first text request cmd->text_in_ptr is NULL as
cmd is memset to 0 in iscsit_allocate_cmd().

Signed-off-by: Varun Prakash <varun@xxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/target/iscsi/iscsi_target.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -2177,6 +2177,7 @@ iscsit_setup_text_cmd(struct iscsi_conn
 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
 	cmd->data_direction	= DMA_NONE;
+	kfree(cmd->text_in_ptr);
 	cmd->text_in_ptr	= NULL;
 
 	return 0;