Merge branch 'atlantic-fixes'

Grant Grundler says:

====================
net: atlantic: more fuzzing fixes

It essentially describes four problems:
1) validate rxd_wb->next_desc_ptr before populating buff->next
2) "frag[0] not initialized" case in aq_ring_rx_clean()
3) limit iterations handling fragments in aq_ring_rx_clean()
4) validate hw_head_ in hw_atl_b0_hw_ring_tx_head_update()

(1) was fixed by Zekun Shen <bruceshenzk@gmail.com> around the same time with
"atlantic: Fix buff_ring OOB in aq_ring_rx_clean" (SHA1 5f50153288452e10).

I've added one "clean up" contribution:
    "net: atlantic: reduce scope of is_rsc_complete"

I tested the "original" patches using chromeos-v5.4 kernel branch:
    https://chromium-review.googlesource.com/q/hashtag:pcinet-atlantic-2022q1+(status:open%20OR%20status:merged)

I've forward ported those patches to 5.18-rc2 and compiled them but am
unable to test them on 5.18-rc2 kernel (logistics problems).

Credit largely goes to ChromeOS Fuzzing team members:
    Aashay Shringarpure, Yi Chou, Shervin Oloumi

V2 changes:
o drop first patch - was already fixed upstream differently
o reduce (4) "validate hw_head_" to simple bounds checking.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 18 insertions, 9 deletions

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
index 77e76c9efd32..8201ce7adb77 100644
--- a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
@@ -346,7 +346,6 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
 		     int budget)
 {
 	struct net_device *ndev = aq_nic_get_ndev(self->aq_nic);
-	bool is_rsc_completed = true;
 	int err = 0;
 
 	for (; (self->sw_head != self->hw_head) && budget;
@@ -364,12 +363,17 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
 			continue;
 
 		if (!buff->is_eop) {
+			unsigned int frag_cnt = 0U;
 			buff_ = buff;
 			do {
+				bool is_rsc_completed = true;
+
 				if (buff_->next >= self->size) {
 					err = -EIO;
 					goto err_exit;
 				}
+
+				frag_cnt++;
 				next_ = buff_->next,
 				buff_ = &self->buff_ring[next_];
 				is_rsc_completed =
@@ -377,18 +381,17 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
 							    next_,
 							    self->hw_head);
 
-				if (unlikely(!is_rsc_completed))
-					break;
+				if (unlikely(!is_rsc_completed) ||
+						frag_cnt > MAX_SKB_FRAGS) {
+					err = 0;
+					goto err_exit;
+				}
 
 				buff->is_error |= buff_->is_error;
 				buff->is_cso_err |= buff_->is_cso_err;
 
 			} while (!buff_->is_eop);
 
-			if (!is_rsc_completed) {
-				err = 0;
-				goto err_exit;
-			}
 			if (buff->is_error ||
 			    (buff->is_lro && buff->is_cso_err)) {
 				buff_ = buff;
@@ -446,7 +449,7 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
 		       ALIGN(hdr_len, sizeof(long)));
 
 		if (buff->len - hdr_len > 0) {
-			skb_add_rx_frag(skb, 0, buff->rxdata.page,
+			skb_add_rx_frag(skb, i++, buff->rxdata.page,
 					buff->rxdata.pg_off + hdr_len,
 					buff->len - hdr_len,
 					AQ_CFG_RX_FRAME_MAX);
@@ -455,7 +458,6 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
 
 		if (!buff->is_eop) {
 			buff_ = buff;
-			i = 1U;
 			do {
 				next_ = buff_->next;
 				buff_ = &self->buff_ring[next_];
diff --git a/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0.c b/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0.c
index d875ce3ec759..15ede7285fb5 100644
--- a/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0.c
+++ b/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0.c
@@ -889,6 +889,13 @@ int hw_atl_b0_hw_ring_tx_head_update(struct aq_hw_s *self,
 		err = -ENXIO;
 		goto err_exit;
 	}
+
+	/* Validate that the new hw_head_ is reasonable. */
+	if (hw_head_ >= ring->size) {
+		err = -ENXIO;
+		goto err_exit;
+	}
+
 	ring->hw_head = hw_head_;
 	err = aq_hw_err_from_flags(self);