[Devel] [PATCH 21/23] iscsi-target: fix memory leak in iscsit_setup_text_cmd()

[Andrei Vagin]

From: Varun Prakash <varun at chelsio.com>

ML: ea8dc5b4cd2195ee582cae28afa4164c6dea1738

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 at chelsio.com>
Cc: <stable at vger.kernel.org> # 4.0+
Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
Signed-off-by: Andrei Vagin <avagin at openvz.org>
---
 drivers/target/iscsi/iscsi_target.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index ea8573e..aeba04a 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -2164,6 +2164,7 @@ iscsit_setup_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
 	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;
-- 
1.8.3.1