5.4-stable review patch. If anyone has any objections, please let me know.
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From: Dragos Tatulea dtatulea@nvidia.com
[ Upstream commit dd6e972cc5890d91d6749bb48e3912721c4e4b25 ]
The kTLS tx handling code is using a mix of get_page() and page_ref_inc() APIs to increment the page reference. But on the release path (mlx5e_ktls_tx_handle_resync_dump_comp()), only put_page() is used.
This is an issue when using pages from large folios: the get_page() references are stored on the folio page while the page_ref_inc() references are stored directly in the given page. On release the folio page will be dereferenced too many times.
This was found while doing kTLS testing with sendfile() + ZC when the served file was read from NFS on a kernel with NFS large folios support (commit 49b29a573da8 ("nfs: add support for large folios")).
Fixes: 84d1bb2b139e ("net/mlx5e: kTLS, Limit DUMP wqe size") Signed-off-by: Dragos Tatulea dtatulea@nvidia.com Signed-off-by: Tariq Toukan tariqt@nvidia.com Link: https://patch.msgid.link/20241107183527.676877-5-tariqt@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c @@ -233,7 +233,7 @@ tx_sync_info_get(struct mlx5e_ktls_offlo while (remaining > 0) { skb_frag_t *frag = &record->frags[i];
- get_page(skb_frag_page(frag)); + page_ref_inc(skb_frag_page(frag)); remaining -= skb_frag_size(frag); info->frags[i++] = *frag; } @@ -321,7 +321,7 @@ void mlx5e_ktls_tx_handle_resync_dump_co stats = sq->stats;
mlx5e_tx_dma_unmap(sq->pdev, dma); - put_page(wi->resync_dump_frag_page); + page_ref_dec(wi->resync_dump_frag_page); stats->tls_dump_packets++; stats->tls_dump_bytes += wi->num_bytes; } @@ -412,12 +412,12 @@ mlx5e_ktls_tx_handle_ooo(struct mlx5e_kt
err_out: for (; i < info.nr_frags; i++) - /* The put_page() here undoes the page ref obtained in tx_sync_info_get(). + /* The page_ref_dec() here undoes the page ref obtained in tx_sync_info_get(). * Page refs obtained for the DUMP WQEs above (by page_ref_add) will be * released only upon their completions (or in mlx5e_free_txqsq_descs, * if channel closes). */ - put_page(skb_frag_page(&info.frags[i])); + page_ref_dec(skb_frag_page(&info.frags[i]));
return MLX5E_KTLS_SYNC_FAIL; }