diff mbox series

[V1,net,1/3] net: ena: Fix undefined state when tx request id is out of bounds

Message ID 20211229140021.8053-2-akiyano@amazon.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series ENA driver bug fixes | expand

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netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers fail 1 blamed authors not CCed: sameehj@amazon.com; 6 maintainers not CCed: hawk@kernel.org daniel@iogearbox.net john.fastabend@gmail.com sameehj@amazon.com bpf@vger.kernel.org ast@kernel.org
netdev/build_clang success Errors and warnings before: 2 this patch: 2
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 64 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Kiyanovski, Arthur Dec. 29, 2021, 2 p.m. UTC
ena_com_tx_comp_req_id_get() checks the req_id of a received completion,
and if it is out of bounds returns -EINVAL. This is a sign that
something is wrong with the device and it needs to be reset.

The current code does not reset the device in this case, which leaves
the driver in an undefined state, where this completion is not properly
handled.

This commit adds a call to handle_invalid_req_id() in ena_clean_tx_irq()
and ena_clean_xdp_irq() which resets the device to fix the issue.

This commit also removes unnecessary request id checks from
validate_tx_req_id() and validate_xdp_req_id(). This check is unneeded
because it was already performed in ena_com_tx_comp_req_id_get(), which
is called right before these functions.

Fixes: 548c4940b9f1 ("net: ena: Implement XDP_TX action")
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_netdev.c | 34 ++++++++++++--------
 1 file changed, 20 insertions(+), 14 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 7d5d885d85d5..2274063e34cc 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -1288,26 +1288,22 @@  static int handle_invalid_req_id(struct ena_ring *ring, u16 req_id,
 
 static int validate_tx_req_id(struct ena_ring *tx_ring, u16 req_id)
 {
-	struct ena_tx_buffer *tx_info = NULL;
+	struct ena_tx_buffer *tx_info;
 
-	if (likely(req_id < tx_ring->ring_size)) {
-		tx_info = &tx_ring->tx_buffer_info[req_id];
-		if (likely(tx_info->skb))
-			return 0;
-	}
+	tx_info = &tx_ring->tx_buffer_info[req_id];
+	if (likely(tx_info->skb))
+		return 0;
 
 	return handle_invalid_req_id(tx_ring, req_id, tx_info, false);
 }
 
 static int validate_xdp_req_id(struct ena_ring *xdp_ring, u16 req_id)
 {
-	struct ena_tx_buffer *tx_info = NULL;
+	struct ena_tx_buffer *tx_info;
 
-	if (likely(req_id < xdp_ring->ring_size)) {
-		tx_info = &xdp_ring->tx_buffer_info[req_id];
-		if (likely(tx_info->xdpf))
-			return 0;
-	}
+	tx_info = &xdp_ring->tx_buffer_info[req_id];
+	if (likely(tx_info->xdpf))
+		return 0;
 
 	return handle_invalid_req_id(xdp_ring, req_id, tx_info, true);
 }
@@ -1332,9 +1328,14 @@  static int ena_clean_tx_irq(struct ena_ring *tx_ring, u32 budget)
 
 		rc = ena_com_tx_comp_req_id_get(tx_ring->ena_com_io_cq,
 						&req_id);
-		if (rc)
+		if (rc) {
+			if (unlikely(rc == -EINVAL))
+				handle_invalid_req_id(tx_ring, req_id, NULL,
+						      false);
 			break;
+		}
 
+		/* validate that the request id points to a valid skb */
 		rc = validate_tx_req_id(tx_ring, req_id);
 		if (rc)
 			break;
@@ -1896,9 +1897,14 @@  static int ena_clean_xdp_irq(struct ena_ring *xdp_ring, u32 budget)
 
 		rc = ena_com_tx_comp_req_id_get(xdp_ring->ena_com_io_cq,
 						&req_id);
-		if (rc)
+		if (rc) {
+			if (unlikely(rc == -EINVAL))
+				handle_invalid_req_id(xdp_ring, req_id, NULL,
+						      true);
 			break;
+		}
 
+		/* validate that the request id points to a valid xdp_frame */
 		rc = validate_xdp_req_id(xdp_ring, req_id);
 		if (rc)
 			break;