From 8ee2a09a1dbb257c9e828ad2497f8e4832dfb142 Mon Sep 17 00:00:00 2001 From: Yehyeong Lee Date: Wed, 7 Oct 2026 10:58:40 +0900 Subject: [PATCH] scsi: libiscsi: Reject a negative task index from parse_pdu_itt A transport that implements parse_pdu_itt hands libiscsi an index taken from the PDU, and both lookups bound it from above only: if (i >= session->cmds_max) i and cmds_max are both int, so a negative index passes and session->cmds[i] is read from before the array. be2iscsi produces one. beiscsi_parse_pdu() assigns the raw tag, *index = (int)itt; and beiscsi_complete_pdu() forwards an unsolicited NOP-In from the hardware async ring without replacing its ITT, so the value is the target's. It also reports the session's own age rather than the one in the tag, which leaves the age comparison in iscsi_verify_itt() with nothing to reject. Bound the index from below in both lookups. Fixes: bfead3b2cb46 ("[SCSI] be2iscsi: Adding msix and mcc_rings V3") Cc: stable@vger.kernel.org Reviewed-by: Mike Christie Signed-off-by: Yehyeong Lee Link: https://patch.msgid.link/20261007015842.634893-2-yhlee@isslab.korea.ac.kr Signed-off-by: Martin K. Petersen (Oracle) --- drivers/scsi/libiscsi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 5cbc51899de0..d73e506e9ba5 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -1191,7 +1191,7 @@ struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt) session->tt->parse_pdu_itt(conn, itt, &i, NULL); else i = get_itt(itt); - if (i >= session->cmds_max) + if (i < 0 || i >= session->cmds_max) return NULL; return session->cmds[i]; @@ -1384,7 +1384,7 @@ int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt) return ISCSI_ERR_BAD_ITT; } - if (i >= session->cmds_max) { + if (i < 0 || i >= session->cmds_max) { iscsi_conn_printk(KERN_ERR, conn, "received invalid itt index %u (max cmds " "%u.\n", i, session->cmds_max);