[PATCH AUTOSEL 6.4 15/25] scsi: target: iscsi: Fix buffer overflow in lio_target_nacl_info_show()

Sasha Levin
2023-09-09T00:39:01Z

From: Konstantin Shelekhin <k.shelekhin@yadro.com>

[ Upstream commit 801f287c93ff95582b0a2d2163f12870a2f076d4 ]

The function lio_target_nacl_info_show() uses sprintf() in a loop to print
details for every iSCSI connection in a session without checking for the
buffer length. With enough iSCSI connections it's possible to overflow the
buffer provided by configfs and corrupt the memory.

This patch replaces sprintf() with sysfs_emit_at() that checks for buffer
boundries.

Signed-off-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Link: https://lore.kernel.org/r/20230722152657.168859-2-k.shelekhin@yadro.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/target/iscsi/iscsi_target_configfs.c | 54 ++++++++++----------
1 file changed, 27 insertions(+), 27 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c
index 5d0f51822414e..c142a67dc7cc2 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -533,102 +533,102 @@ static ssize_t lio_target_nacl_info_show(struct config_item *item, char *page)
spin_lock_bh(&se_nacl->nacl_sess_lock);
se_sess = se_nacl->nacl_sess;
if (!se_sess) {
- rb += sprintf(page+rb, "No active iSCSI Session for Initiator"
+ rb += sysfs_emit_at(page, rb, "No active iSCSI Session for Initiator"
" Endpoint: %s\n", se_nacl->initiatorname);
} else {
sess = se_sess->fabric_sess_ptr;

- rb += sprintf(page+rb, "InitiatorName: %s\n",
+ rb += sysfs_emit_at(page, rb, "InitiatorName: %s\n",
sess->sess_ops->InitiatorName);
- rb += sprintf(page+rb, "InitiatorAlias: %s\n",
+ rb += sysfs_emit_at(page, rb, "InitiatorAlias: %s\n",
sess->sess_ops->InitiatorAlias);

- rb += sprintf(page+rb,
+ rb += sysfs_emit_at(page, rb,
"LIO Session ID: %u ISID: 0x%6ph TSIH: %hu ",
sess->sid, sess->isid, sess->tsih);
- rb += sprintf(page+rb, "SessionType: %s\n",
+ rb += sysfs_emit_at(page, rb, "SessionType: %s\n",
(sess->sess_ops->SessionType) ?
"Discovery" : "Normal");
- rb += sprintf(page+rb, "Session State: ");
+ rb += sysfs_emit_at(page, rb, "Session State: ");
switch (sess->session_state) {
case TARG_SESS_STATE_FREE:
- rb += sprintf(page+rb, "TARG_SESS_FREE\n");
+ rb += sysfs_emit_at(page, rb, "TARG_SESS_FREE\n");
break;
case TARG_SESS_STATE_ACTIVE:
- rb += sprintf(page+rb, "TARG_SESS_STATE_ACTIVE\n");
+ rb += sysfs_emit_at(page, rb, "TARG_SESS_STATE_ACTIVE\n");
break;
case TARG_SESS_STATE_LOGGED_IN:
- rb += sprintf(page+rb, "TARG_SESS_STATE_LOGGED_IN\n");
+ rb += sysfs_emit_at(page, rb, "TARG_SESS_STATE_LOGGED_IN\n");
break;
case TARG_SESS_STATE_FAILED:
- rb += sprintf(page+rb, "TARG_SESS_STATE_FAILED\n");
+ rb += sysfs_emit_at(page, rb, "TARG_SESS_STATE_FAILED\n");
break;
case TARG_SESS_STATE_IN_CONTINUE:
- rb += sprintf(page+rb, "TARG_SESS_STATE_IN_CONTINUE\n");
+ rb += sysfs_emit_at(page, rb, "TARG_SESS_STATE_IN_CONTINUE\n");
break;
default:
- rb += sprintf(page+rb, "ERROR: Unknown Session"
+ rb += sysfs_emit_at(page, rb, "ERROR: Unknown Session"
" State!\n");
break;
}

- rb += sprintf(page+rb, "---------------------[iSCSI Session"
+ rb += sysfs_emit_at(page, rb, "---------------------[iSCSI Session"
" Values]-----------------------\n");
- rb += sprintf(page+rb, " CmdSN/WR : CmdSN/WC : ExpCmdSN"
+ rb += sysfs_emit_at(page, rb, " CmdSN/WR : CmdSN/WC : ExpCmdSN"
" : MaxCmdSN : ITT : TTT\n");
max_cmd_sn = (u32) atomic_read(&sess->max_cmd_sn);
- rb += sprintf(page+rb, " 0x%08x 0x%08x 0x%08x 0x%08x"
+ rb += sysfs_emit_at(page, rb, " 0x%08x 0x%08x 0x%08x 0x%08x"
" 0x%08x 0x%08x\n",
sess->cmdsn_window,
(max_cmd_sn - sess->exp_cmd_sn) + 1,
sess->exp_cmd_sn, max_cmd_sn,
sess->init_task_tag, sess->targ_xfer_tag);
- rb += sprintf(page+rb, "----------------------[iSCSI"
+ rb += sysfs_emit_at(page, rb, "----------------------[iSCSI"
" Connections]-------------------------\n");

spin_lock(&sess->conn_lock);
list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
- rb += sprintf(page+rb, "CID: %hu Connection"
+ rb += sysfs_emit_at(page, rb, "CID: %hu Connection"
" State: ", conn->cid);
switch (conn->conn_state) {
case TARG_CONN_STATE_FREE:
- rb += sprintf(page+rb,
+ rb += sysfs_emit_at(page, rb,
"TARG_CONN_STATE_FREE\n");
break;
case TARG_CONN_STATE_XPT_UP:
- rb += sprintf(page+rb,
+ rb += sysfs_emit_at(page, rb,
"TARG_CONN_STATE_XPT_UP\n");
break;
case TARG_CONN_STATE_IN_LOGIN:
- rb += sprintf(page+rb,
+ rb += sysfs_emit_at(page, rb,
"TARG_CONN_STATE_IN_LOGIN\n");
break;
case TARG_CONN_STATE_LOGGED_IN:
- rb += sprintf(page+rb,
+ rb += sysfs_emit_at(page, rb,
"TARG_CONN_STATE_LOGGED_IN\n");
break;
case TARG_CONN_STATE_IN_LOGOUT:
- rb += sprintf(page+rb,
+ rb += sysfs_emit_at(page, rb,
"TARG_CONN_STATE_IN_LOGOUT\n");
break;
case TARG_CONN_STATE_LOGOUT_REQUESTED:
- rb += sprintf(page+rb,
+ rb += sysfs_emit_at(page, rb,
"TARG_CONN_STATE_LOGOUT_REQUESTED\n");
break;
case TARG_CONN_STATE_CLEANUP_WAIT:
- rb += sprintf(page+rb,
+ rb += sysfs_emit_at(page, rb,
"TARG_CONN_STATE_CLEANUP_WAIT\n");
break;
default:
- rb += sprintf(page+rb,
+ rb += sysfs_emit_at(page, rb,
"ERROR: Unknown Connection State!\n");
break;
}

- rb += sprintf(page+rb, " Address %pISc %s", &conn->login_sockaddr,
+ rb += sysfs_emit_at(page, rb, " Address %pISc %s", &conn->login_sockaddr,
(conn->network_transport == ISCSI_TCP) ?
"TCP" : "SCTP");
- rb += sprintf(page+rb, " StatSN: 0x%08x\n",
+ rb += sysfs_emit_at(page, rb, " StatSN: 0x%08x\n",
conn->stat_sn);
}
spin_unlock(&sess->conn_lock);
--
2.40.1