4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mike Christie mchristi@redhat.com
commit 26abc916a898d34c5ad159315a2f683def3c5555 upstream.
The problem is that iscsi_login_zero_tsih_s1 sets conn->sess early in iscsi_login_set_conn_values. If the function fails later like when we alloc the idr it does kfree(sess) and leaves the conn->sess pointer set. iscsi_login_zero_tsih_s1 then returns -Exyz and we then call iscsi_target_login_sess_out and access the freed memory.
This patch has iscsi_login_zero_tsih_s1 either completely setup the session or completely tear it down, so later in iscsi_target_login_sess_out we can just check for it being set to the connection.
Cc: stable@vger.kernel.org Fixes: 0957627a9960 ("iscsi-target: Fix sess allocation leak in...") Signed-off-by: Mike Christie mchristi@redhat.com Acked-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Matthew Wilcox willy@infradead.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/target/iscsi/iscsi_target_login.c | 35 ++++++++++++++++++------------ 1 file changed, 21 insertions(+), 14 deletions(-)
--- a/drivers/target/iscsi/iscsi_target_login.c +++ b/drivers/target/iscsi/iscsi_target_login.c @@ -323,8 +323,7 @@ static int iscsi_login_zero_tsih_s1( pr_err("idr_alloc() for sess_idr failed\n"); iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR, ISCSI_LOGIN_STATUS_NO_RESOURCES); - kfree(sess); - return -ENOMEM; + goto free_sess; }
sess->creation_time = get_jiffies_64(); @@ -340,20 +339,28 @@ static int iscsi_login_zero_tsih_s1( ISCSI_LOGIN_STATUS_NO_RESOURCES); pr_err("Unable to allocate memory for" " struct iscsi_sess_ops.\n"); - kfree(sess); - return -ENOMEM; + goto remove_idr; }
sess->se_sess = transport_init_session(TARGET_PROT_NORMAL); if (IS_ERR(sess->se_sess)) { iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR, ISCSI_LOGIN_STATUS_NO_RESOURCES); - kfree(sess->sess_ops); - kfree(sess); - return -ENOMEM; + goto free_ops; }
return 0; + +free_ops: + kfree(sess->sess_ops); +remove_idr: + spin_lock_bh(&sess_idr_lock); + idr_remove(&sess_idr, sess->session_index); + spin_unlock_bh(&sess_idr_lock); +free_sess: + kfree(sess); + conn->sess = NULL; + return -ENOMEM; }
static int iscsi_login_zero_tsih_s2( @@ -1142,13 +1149,13 @@ void iscsi_target_login_sess_out(struct ISCSI_LOGIN_STATUS_INIT_ERR); if (!zero_tsih || !conn->sess) goto old_sess_out; - if (conn->sess->se_sess) - transport_free_session(conn->sess->se_sess); - if (conn->sess->session_index != 0) { - spin_lock_bh(&sess_idr_lock); - idr_remove(&sess_idr, conn->sess->session_index); - spin_unlock_bh(&sess_idr_lock); - } + + transport_free_session(conn->sess->se_sess); + + spin_lock_bh(&sess_idr_lock); + idr_remove(&sess_idr, conn->sess->session_index); + spin_unlock_bh(&sess_idr_lock); + kfree(conn->sess->sess_ops); kfree(conn->sess); conn->sess = NULL;