From: Mike Christie <[email protected]> [ Upstream commit f484a794e4ee2a9ce61f52a78e810ac45f3fe3b3 ]
If during iscsi_sw_tcp_session_create() iscsi_tcp_r2tpool_alloc() fails, userspace could be accessing the host's ipaddress attr. If we then free the session via iscsi_session_teardown() while userspace is still accessing the session we will hit a use after free bug. Set the tcp_sw_host->session after we have completed session creation and can no longer fail. Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Mike Christie <[email protected]> Reviewed-by: Lee Duncan <[email protected]> Acked-by: Ding Hui <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- drivers/scsi/iscsi_tcp.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c index 6485c1aa9e74..252d7881f99c 100644 --- a/drivers/scsi/iscsi_tcp.c +++ b/drivers/scsi/iscsi_tcp.c @@ -802,7 +802,7 @@ static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param, char *buf) { struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost); - struct iscsi_session *session = tcp_sw_host->session; + struct iscsi_session *session; struct iscsi_conn *conn; struct iscsi_tcp_conn *tcp_conn; struct iscsi_sw_tcp_conn *tcp_sw_conn; @@ -812,6 +812,7 @@ static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, switch (param) { case ISCSI_HOST_PARAM_IPADDRESS: + session = tcp_sw_host->session; if (!session) return -ENOTCONN; @@ -906,12 +907,14 @@ iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, if (!cls_session) goto remove_host; session = cls_session->dd_data; - tcp_sw_host = iscsi_host_priv(shost); - tcp_sw_host->session = session; shost->can_queue = session->scsi_cmds_max; if (iscsi_tcp_r2tpool_alloc(session)) goto remove_session; + + /* We are now fully setup so expose the session to sysfs. */ + tcp_sw_host = iscsi_host_priv(shost); + tcp_sw_host->session = session; return cls_session; remove_session: -- 2.39.0 -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/open-iscsi/20230131150100.1250267-3-sashal%40kernel.org.
