6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ziwei Xiao ziweixiao@google.com
commit 6f4d93b78ade0a4c2cafd587f7b429ce95abb02e upstream.
gve_rx_free_skb incorrectly leaves napi->skb referencing an skb after it is freed with dev_kfree_skb_any(). This can result in a subsequent call to napi_get_frags returning a dangling pointer.
Fix this by clearing napi->skb before the skb is freed.
Fixes: 9b8dd5e5ea48 ("gve: DQO: Add RX path") Cc: stable@vger.kernel.org Reported-by: Shailend Chand shailend@google.com Signed-off-by: Ziwei Xiao ziweixiao@google.com Reviewed-by: Harshitha Ramamurthy hramamurthy@google.com Reviewed-by: Shailend Chand shailend@google.com Reviewed-by: Praveen Kaligineedi pkaligineedi@google.com Link: https://lore.kernel.org/r/20240612001654.923887-1-ziweixiao@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/google/gve/gve_rx_dqo.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
--- a/drivers/net/ethernet/google/gve/gve_rx_dqo.c +++ b/drivers/net/ethernet/google/gve/gve_rx_dqo.c @@ -506,11 +506,13 @@ static void gve_rx_skb_hash(struct sk_bu skb_set_hash(skb, le32_to_cpu(compl_desc->hash), hash_type); }
-static void gve_rx_free_skb(struct gve_rx_ring *rx) +static void gve_rx_free_skb(struct napi_struct *napi, struct gve_rx_ring *rx) { if (!rx->ctx.skb_head) return;
+ if (rx->ctx.skb_head == napi->skb) + napi->skb = NULL; dev_kfree_skb_any(rx->ctx.skb_head); rx->ctx.skb_head = NULL; rx->ctx.skb_tail = NULL; @@ -783,7 +785,7 @@ int gve_rx_poll_dqo(struct gve_notify_bl
err = gve_rx_dqo(napi, rx, compl_desc, rx->q_num); if (err < 0) { - gve_rx_free_skb(rx); + gve_rx_free_skb(napi, rx); u64_stats_update_begin(&rx->statss); if (err == -ENOMEM) rx->rx_skb_alloc_fail++; @@ -826,7 +828,7 @@ int gve_rx_poll_dqo(struct gve_notify_bl
/* gve_rx_complete_skb() will consume skb if successful */ if (gve_rx_complete_skb(rx, napi, compl_desc, feat) != 0) { - gve_rx_free_skb(rx); + gve_rx_free_skb(napi, rx); u64_stats_update_begin(&rx->statss); rx->rx_desc_err_dropped_pkt++; u64_stats_update_end(&rx->statss);