FAILED: patch "[PATCH] gve: fix incorrect buffer cleanup in" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] gve: fix incorrect buffer cleanup in" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x fb868db5f4bccd7a78219313ab2917429f715cea
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026030918-unflawed-unmasking-3b8d@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From fb868db5f4bccd7a78219313ab2917429f715cea Mon Sep 17 00:00:00 2001
From: Ankit Garg <nktgrg@google.com>
Date: Fri, 20 Feb 2026 13:53:24 -0800
Subject: [PATCH] gve: fix incorrect buffer cleanup in
 gve_tx_clean_pending_packets for QPL

In DQ-QPL mode, gve_tx_clean_pending_packets() incorrectly uses the RDA
buffer cleanup path. It iterates num_bufs times and attempts to unmap
entries in the dma array.

This leads to two issues:
1. The dma array shares storage with tx_qpl_buf_ids (union).
 Interpreting buffer IDs as DMA addresses results in attempting to
 unmap incorrect memory locations.
2. num_bufs in QPL mode (counting 2K chunks) can significantly exceed
 the size of the dma array, causing out-of-bounds access warnings
(trace below is how we noticed this issue).

UBSAN: array-index-out-of-bounds in
drivers/net/ethernet/drivers/net/ethernet/google/gve/gve_tx_dqo.c:178:5 index 18 is out of
range for type 'dma_addr_t[18]' (aka 'unsigned long long[18]')
Workqueue: gve gve_service_task [gve]
Call Trace:
<TASK>
dump_stack_lvl+0x33/0xa0
__ubsan_handle_out_of_bounds+0xdc/0x110
gve_tx_stop_ring_dqo+0x182/0x200 [gve]
gve_close+0x1be/0x450 [gve]
gve_reset+0x99/0x120 [gve]
gve_service_task+0x61/0x100 [gve]
process_scheduled_works+0x1e9/0x380

Fix this by properly checking for QPL mode and delegating to
gve_free_tx_qpl_bufs() to reclaim the buffers.

Cc: stable@vger.kernel.org
Fixes: a6fb8d5a8b69 ("gve: Tx path for DQO-QPL")
Signed-off-by: Ankit Garg <nktgrg@google.com>
Reviewed-by: Jordan Rhee <jordanrhee@google.com>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
Signed-off-by: Joshua Washington <joshwash@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260220215324.1631350-1-joshwash@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/google/gve/gve_tx_dqo.c b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
index 28e85730f785..b57e8f13cb51 100644
--- a/drivers/net/ethernet/google/gve/gve_tx_dqo.c
+++ b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
@@ -167,6 +167,25 @@ gve_free_pending_packet(struct gve_tx_ring *tx,
 	}
 }
 
+static void gve_unmap_packet(struct device *dev,
+			     struct gve_tx_pending_packet_dqo *pkt)
+{
+	int i;
+
+	if (!pkt->num_bufs)
+		return;
+
+	/* SKB linear portion is guaranteed to be mapped */
+	dma_unmap_single(dev, dma_unmap_addr(pkt, dma[0]),
+			 dma_unmap_len(pkt, len[0]), DMA_TO_DEVICE);
+	for (i = 1; i < pkt->num_bufs; i++) {
+		netmem_dma_unmap_page_attrs(dev, dma_unmap_addr(pkt, dma[i]),
+					    dma_unmap_len(pkt, len[i]),
+					    DMA_TO_DEVICE, 0);
+	}
+	pkt->num_bufs = 0;
+}
+
 /* gve_tx_free_desc - Cleans up all pending tx requests and buffers.
  */
 static void gve_tx_clean_pending_packets(struct gve_tx_ring *tx)
@@ -176,21 +195,12 @@ static void gve_tx_clean_pending_packets(struct gve_tx_ring *tx)
 	for (i = 0; i < tx->dqo.num_pending_packets; i++) {
 		struct gve_tx_pending_packet_dqo *cur_state =
 			&tx->dqo.pending_packets[i];
-		int j;
 
-		for (j = 0; j < cur_state->num_bufs; j++) {
-			if (j == 0) {
-				dma_unmap_single(tx->dev,
-					dma_unmap_addr(cur_state, dma[j]),
-					dma_unmap_len(cur_state, len[j]),
-					DMA_TO_DEVICE);
-			} else {
-				dma_unmap_page(tx->dev,
-					dma_unmap_addr(cur_state, dma[j]),
-					dma_unmap_len(cur_state, len[j]),
-					DMA_TO_DEVICE);
-			}
-		}
+		if (tx->dqo.qpl)
+			gve_free_tx_qpl_bufs(tx, cur_state);
+		else
+			gve_unmap_packet(tx->dev, cur_state);
+
 		if (cur_state->skb) {
 			dev_consume_skb_any(cur_state->skb);
 			cur_state->skb = NULL;
@@ -1157,22 +1167,6 @@ static void remove_from_list(struct gve_tx_ring *tx,
 	}
 }
 
-static void gve_unmap_packet(struct device *dev,
-			     struct gve_tx_pending_packet_dqo *pkt)
-{
-	int i;
-
-	/* SKB linear portion is guaranteed to be mapped */
-	dma_unmap_single(dev, dma_unmap_addr(pkt, dma[0]),
-			 dma_unmap_len(pkt, len[0]), DMA_TO_DEVICE);
-	for (i = 1; i < pkt->num_bufs; i++) {
-		netmem_dma_unmap_page_attrs(dev, dma_unmap_addr(pkt, dma[i]),
-					    dma_unmap_len(pkt, len[i]),
-					    DMA_TO_DEVICE, 0);
-	}
-	pkt->num_bufs = 0;
-}
-
 /* Completion types and expected behavior:
  * No Miss compl + Packet compl = Packet completed normally.
  * Miss compl + Re-inject compl = Packet completed normally.

[PATCH 6.6.y] gve: fix incorrect buffer cleanup in gve_tx_clean_pending_packets for QPL

[Sasha Levin]

From: Ankit Garg <nktgrg@google.com>

[ Upstream commit fb868db5f4bccd7a78219313ab2917429f715cea ]

In DQ-QPL mode, gve_tx_clean_pending_packets() incorrectly uses the RDA
buffer cleanup path. It iterates num_bufs times and attempts to unmap
entries in the dma array.

This leads to two issues:
1. The dma array shares storage with tx_qpl_buf_ids (union).
 Interpreting buffer IDs as DMA addresses results in attempting to
 unmap incorrect memory locations.
2. num_bufs in QPL mode (counting 2K chunks) can significantly exceed
 the size of the dma array, causing out-of-bounds access warnings
(trace below is how we noticed this issue).

UBSAN: array-index-out-of-bounds in
drivers/net/ethernet/drivers/net/ethernet/google/gve/gve_tx_dqo.c:178:5 index 18 is out of
range for type 'dma_addr_t[18]' (aka 'unsigned long long[18]')
Workqueue: gve gve_service_task [gve]
Call Trace:
<TASK>
dump_stack_lvl+0x33/0xa0
__ubsan_handle_out_of_bounds+0xdc/0x110
gve_tx_stop_ring_dqo+0x182/0x200 [gve]
gve_close+0x1be/0x450 [gve]
gve_reset+0x99/0x120 [gve]
gve_service_task+0x61/0x100 [gve]
process_scheduled_works+0x1e9/0x380

Fix this by properly checking for QPL mode and delegating to
gve_free_tx_qpl_bufs() to reclaim the buffers.

Cc: stable@vger.kernel.org
Fixes: a6fb8d5a8b69 ("gve: Tx path for DQO-QPL")
Signed-off-by: Ankit Garg <nktgrg@google.com>
Reviewed-by: Jordan Rhee <jordanrhee@google.com>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
Signed-off-by: Joshua Washington <joshwash@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260220215324.1631350-1-joshwash@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ netmem_dma_unmap_page_attrs() => dma_unmap_page() ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/google/gve/gve_tx_dqo.c | 54 +++++++++-----------
 1 file changed, 24 insertions(+), 30 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve_tx_dqo.c b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
index 857749fef37cf..e3c46f791abdc 100644
--- a/drivers/net/ethernet/google/gve/gve_tx_dqo.c
+++ b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
@@ -157,6 +157,24 @@ gve_free_pending_packet(struct gve_tx_ring *tx,
 	}
 }
 
+static void gve_unmap_packet(struct device *dev,
+			     struct gve_tx_pending_packet_dqo *pkt)
+{
+	int i;
+
+	if (!pkt->num_bufs)
+		return;
+
+	/* SKB linear portion is guaranteed to be mapped */
+	dma_unmap_single(dev, dma_unmap_addr(pkt, dma[0]),
+			 dma_unmap_len(pkt, len[0]), DMA_TO_DEVICE);
+	for (i = 1; i < pkt->num_bufs; i++) {
+		dma_unmap_page(dev, dma_unmap_addr(pkt, dma[i]),
+			       dma_unmap_len(pkt, len[i]), DMA_TO_DEVICE);
+	}
+	pkt->num_bufs = 0;
+}
+
 /* gve_tx_free_desc - Cleans up all pending tx requests and buffers.
  */
 static void gve_tx_clean_pending_packets(struct gve_tx_ring *tx)
@@ -166,21 +184,12 @@ static void gve_tx_clean_pending_packets(struct gve_tx_ring *tx)
 	for (i = 0; i < tx->dqo.num_pending_packets; i++) {
 		struct gve_tx_pending_packet_dqo *cur_state =
 			&tx->dqo.pending_packets[i];
-		int j;
-
-		for (j = 0; j < cur_state->num_bufs; j++) {
-			if (j == 0) {
-				dma_unmap_single(tx->dev,
-					dma_unmap_addr(cur_state, dma[j]),
-					dma_unmap_len(cur_state, len[j]),
-					DMA_TO_DEVICE);
-			} else {
-				dma_unmap_page(tx->dev,
-					dma_unmap_addr(cur_state, dma[j]),
-					dma_unmap_len(cur_state, len[j]),
-					DMA_TO_DEVICE);
-			}
-		}
+
+		if (tx->dqo.qpl)
+			gve_free_tx_qpl_bufs(tx, cur_state);
+		else
+			gve_unmap_packet(tx->dev, cur_state);
+
 		if (cur_state->skb) {
 			dev_consume_skb_any(cur_state->skb);
 			cur_state->skb = NULL;
@@ -992,21 +1001,6 @@ static void remove_from_list(struct gve_tx_ring *tx,
 	}
 }
 
-static void gve_unmap_packet(struct device *dev,
-			     struct gve_tx_pending_packet_dqo *pkt)
-{
-	int i;
-
-	/* SKB linear portion is guaranteed to be mapped */
-	dma_unmap_single(dev, dma_unmap_addr(pkt, dma[0]),
-			 dma_unmap_len(pkt, len[0]), DMA_TO_DEVICE);
-	for (i = 1; i < pkt->num_bufs; i++) {
-		dma_unmap_page(dev, dma_unmap_addr(pkt, dma[i]),
-			       dma_unmap_len(pkt, len[i]), DMA_TO_DEVICE);
-	}
-	pkt->num_bufs = 0;
-}
-
 /* Completion types and expected behavior:
  * No Miss compl + Packet compl = Packet completed normally.
  * Miss compl + Re-inject compl = Packet completed normally.
-- 
2.51.0

Re: [PATCH 6.6.y] gve: fix incorrect buffer cleanup in gve_tx_clean_pending_packets for QPL

[Ankit Garg]

On Mon, Mar 9, 2026 at 6:00 AM Sasha Levin <sashal@kernel.org> wrote:
>
> From: Ankit Garg <nktgrg@google.com>
>
> [ Upstream commit fb868db5f4bccd7a78219313ab2917429f715cea ]
>
> In DQ-QPL mode, gve_tx_clean_pending_packets() incorrectly uses the RDA
> buffer cleanup path. It iterates num_bufs times and attempts to unmap
> entries in the dma array.
>
> This leads to two issues:
> 1. The dma array shares storage with tx_qpl_buf_ids (union).
>  Interpreting buffer IDs as DMA addresses results in attempting to
>  unmap incorrect memory locations.
> 2. num_bufs in QPL mode (counting 2K chunks) can significantly exceed
>  the size of the dma array, causing out-of-bounds access warnings
> (trace below is how we noticed this issue).
>
> UBSAN: array-index-out-of-bounds in
> drivers/net/ethernet/drivers/net/ethernet/google/gve/gve_tx_dqo.c:178:5 index 18 is out of
> range for type 'dma_addr_t[18]' (aka 'unsigned long long[18]')
> Workqueue: gve gve_service_task [gve]
> Call Trace:
> <TASK>
> dump_stack_lvl+0x33/0xa0
> __ubsan_handle_out_of_bounds+0xdc/0x110
> gve_tx_stop_ring_dqo+0x182/0x200 [gve]
> gve_close+0x1be/0x450 [gve]
> gve_reset+0x99/0x120 [gve]
> gve_service_task+0x61/0x100 [gve]
> process_scheduled_works+0x1e9/0x380
>
> Fix this by properly checking for QPL mode and delegating to
> gve_free_tx_qpl_bufs() to reclaim the buffers.
>
> Cc: stable@vger.kernel.org
> Fixes: a6fb8d5a8b69 ("gve: Tx path for DQO-QPL")
> Signed-off-by: Ankit Garg <nktgrg@google.com>
> Reviewed-by: Jordan Rhee <jordanrhee@google.com>
> Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
> Signed-off-by: Joshua Washington <joshwash@google.com>
> Reviewed-by: Simon Horman <horms@kernel.org>
> Link: https://patch.msgid.link/20260220215324.1631350-1-joshwash@google.com
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> [ netmem_dma_unmap_page_attrs() => dma_unmap_page() ]
> Signed-off-by: Sasha Levin <sashal@kernel.org>

Reviewed-by: Ankit Garg <nktgrg@google.com>

Thank you very much!
> ---
>  drivers/net/ethernet/google/gve/gve_tx_dqo.c | 54 +++++++++-----------
>  1 file changed, 24 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/net/ethernet/google/gve/gve_tx_dqo.c b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
> index 857749fef37cf..e3c46f791abdc 100644
> --- a/drivers/net/ethernet/google/gve/gve_tx_dqo.c
> +++ b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
> @@ -157,6 +157,24 @@ gve_free_pending_packet(struct gve_tx_ring *tx,
>         }
>  }
>
> +static void gve_unmap_packet(struct device *dev,
> +                            struct gve_tx_pending_packet_dqo *pkt)
> +{
> +       int i;
> +
> +       if (!pkt->num_bufs)
> +               return;
> +
> +       /* SKB linear portion is guaranteed to be mapped */
> +       dma_unmap_single(dev, dma_unmap_addr(pkt, dma[0]),
> +                        dma_unmap_len(pkt, len[0]), DMA_TO_DEVICE);
> +       for (i = 1; i < pkt->num_bufs; i++) {
> +               dma_unmap_page(dev, dma_unmap_addr(pkt, dma[i]),
> +                              dma_unmap_len(pkt, len[i]), DMA_TO_DEVICE);
> +       }
> +       pkt->num_bufs = 0;
> +}
> +
>  /* gve_tx_free_desc - Cleans up all pending tx requests and buffers.
>   */
>  static void gve_tx_clean_pending_packets(struct gve_tx_ring *tx)
> @@ -166,21 +184,12 @@ static void gve_tx_clean_pending_packets(struct gve_tx_ring *tx)
>         for (i = 0; i < tx->dqo.num_pending_packets; i++) {
>                 struct gve_tx_pending_packet_dqo *cur_state =
>                         &tx->dqo.pending_packets[i];
> -               int j;
> -
> -               for (j = 0; j < cur_state->num_bufs; j++) {
> -                       if (j == 0) {
> -                               dma_unmap_single(tx->dev,
> -                                       dma_unmap_addr(cur_state, dma[j]),
> -                                       dma_unmap_len(cur_state, len[j]),
> -                                       DMA_TO_DEVICE);
> -                       } else {
> -                               dma_unmap_page(tx->dev,
> -                                       dma_unmap_addr(cur_state, dma[j]),
> -                                       dma_unmap_len(cur_state, len[j]),
> -                                       DMA_TO_DEVICE);
> -                       }
> -               }
> +
> +               if (tx->dqo.qpl)
> +                       gve_free_tx_qpl_bufs(tx, cur_state);
> +               else
> +                       gve_unmap_packet(tx->dev, cur_state);
> +
>                 if (cur_state->skb) {
>                         dev_consume_skb_any(cur_state->skb);
>                         cur_state->skb = NULL;
> @@ -992,21 +1001,6 @@ static void remove_from_list(struct gve_tx_ring *tx,
>         }
>  }
>
> -static void gve_unmap_packet(struct device *dev,
> -                            struct gve_tx_pending_packet_dqo *pkt)
> -{
> -       int i;
> -
> -       /* SKB linear portion is guaranteed to be mapped */
> -       dma_unmap_single(dev, dma_unmap_addr(pkt, dma[0]),
> -                        dma_unmap_len(pkt, len[0]), DMA_TO_DEVICE);
> -       for (i = 1; i < pkt->num_bufs; i++) {
> -               dma_unmap_page(dev, dma_unmap_addr(pkt, dma[i]),
> -                              dma_unmap_len(pkt, len[i]), DMA_TO_DEVICE);
> -       }
> -       pkt->num_bufs = 0;
> -}
> -
>  /* Completion types and expected behavior:
>   * No Miss compl + Packet compl = Packet completed normally.
>   * Miss compl + Re-inject compl = Packet completed normally.
> --
> 2.51.0
>