Merge tag 'ceph-for-6.5-rc2' of https://github.com/ceph/ceph-client

Pull ceph fix from Ilya Dryomov:
 "A fix to prevent a potential buffer overrun in the messenger, marked
  for stable"

* tag 'ceph-for-6.5-rc2' of https://github.com/ceph/ceph-client:
  libceph: harden msgr2.1 frame segment length checks

Author: torvalds

net/ceph/messenger_v2.c

@@ -390,6 +390,8 @@ static int head_onwire_len(int ctrl_len, bool secure)
 	int head_len;
 	int rem_len;
 
+	BUG_ON(ctrl_len < 0 || ctrl_len > CEPH_MSG_MAX_CONTROL_LEN);
+
 	if (secure) {
 		head_len = CEPH_PREAMBLE_SECURE_LEN;
 		if (ctrl_len > CEPH_PREAMBLE_INLINE_LEN) {
@@ -408,6 +410,10 @@ static int head_onwire_len(int ctrl_len, bool secure)
 static int __tail_onwire_len(int front_len, int middle_len, int data_len,
 			     bool secure)
 {
+	BUG_ON(front_len < 0 || front_len > CEPH_MSG_MAX_FRONT_LEN ||
+	       middle_len < 0 || middle_len > CEPH_MSG_MAX_MIDDLE_LEN ||
+	       data_len < 0 || data_len > CEPH_MSG_MAX_DATA_LEN);
+
 	if (!front_len && !middle_len && !data_len)
 		return 0;
 
@@ -520,29 +526,34 @@ static int decode_preamble(void *p, struct ceph_frame_desc *desc)
 		desc->fd_aligns[i] = ceph_decode_16(&p);
 	}
 
-	/*
-	 * This would fire for FRAME_TAG_WAIT (it has one empty
-	 * segment), but we should never get it as client.
-	 */
-	if (!desc->fd_lens[desc->fd_seg_cnt - 1]) {
-		pr_err("last segment empty\n");
+	if (desc->fd_lens[0] < 0 ||
+	    desc->fd_lens[0] > CEPH_MSG_MAX_CONTROL_LEN) {
+		pr_err("bad control segment length %d\n", desc->fd_lens[0]);
 		return -EINVAL;
 	}
-
-	if (desc->fd_lens[0] > CEPH_MSG_MAX_CONTROL_LEN) {
-		pr_err("control segment too big %d\n", desc->fd_lens[0]);
+	if (desc->fd_lens[1] < 0 ||
+	    desc->fd_lens[1] > CEPH_MSG_MAX_FRONT_LEN) {
+		pr_err("bad front segment length %d\n", desc->fd_lens[1]);
 		return -EINVAL;
 	}
-	if (desc->fd_lens[1] > CEPH_MSG_MAX_FRONT_LEN) {
-		pr_err("front segment too big %d\n", desc->fd_lens[1]);
+	if (desc->fd_lens[2] < 0 ||
+	    desc->fd_lens[2] > CEPH_MSG_MAX_MIDDLE_LEN) {
+		pr_err("bad middle segment length %d\n", desc->fd_lens[2]);
 		return -EINVAL;
 	}
-	if (desc->fd_lens[2] > CEPH_MSG_MAX_MIDDLE_LEN) {
-		pr_err("middle segment too big %d\n", desc->fd_lens[2]);
+	if (desc->fd_lens[3] < 0 ||
+	    desc->fd_lens[3] > CEPH_MSG_MAX_DATA_LEN) {
+		pr_err("bad data segment length %d\n", desc->fd_lens[3]);
 		return -EINVAL;
 	}
-	if (desc->fd_lens[3] > CEPH_MSG_MAX_DATA_LEN) {
-		pr_err("data segment too big %d\n", desc->fd_lens[3]);
+
+	/*
+	 * This would fire for FRAME_TAG_WAIT (it has one empty
+	 * segment), but we should never get it as client.
+	 */
+	if (!desc->fd_lens[desc->fd_seg_cnt - 1]) {
+		pr_err("last segment empty, segment count %d\n",
+		       desc->fd_seg_cnt);
 		return -EINVAL;
 	}