From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CBFDC46E005; Tue, 21 Jul 2026 19:48:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784663295; cv=none; b=MJaqa9+hsrAIsRRAQhVP+mtd6iou+PhlLyjRWd9yo7zN1EA06ZO8PbMMl+6jZdoOaiPSF9NTYnq2H8ky2NwR5wCQx8ZdqcZnRWDjYfN5mvO+ooahZvPVngegl8n+KOFHpNKLo4N12UL7XRwNZ2JGbSdZSTNc+O/rtZFkDfs9eYQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784663295; c=relaxed/simple; bh=TconcYdGEkRLrYQl0cE/qz0lt9CqnZbHe5fNzbzi7po=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=t88NuOSGF2wHMgIdHR4Jo+KkQSqI92aXnvcm4VoUJlI8vl08qfRV+BGRCS0osAnyo5al3OIMEuED3Ti977sU1C+KOF07YLTAJOqLfNtQauvbvDluXgLQ51TtSlqhn2o40+qjeoZAXxTsyT8dcCXGW3bY8JUgCG+pAioGot+hzuM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gmpNUhS4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gmpNUhS4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B8CE1F00A3A; Tue, 21 Jul 2026 19:48:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784663289; bh=4nNefw1vWQO9qmYGvcOTp3gcpLMcnhCpzMrITJSJOu0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gmpNUhS4Q2gwNzKA8SZ3AEsFRF9m5e4pXBxDpn1yz5JhIySksql6ZYTFXWYB3BEcq a0Djr6Cjg5dJPZeeX8FY3E/tf9d1amCmJYCuyWQ9oYywMLNSQ3QOjiiq5uzQGuuxP0 9RmRxUZVZSg8AP5gj0tV+1DDkBFvTtGCm/Xfd+u0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Feng Liu , Eran Ben Elisha , Tariq Toukan , Paolo Abeni , Sasha Levin Subject: [PATCH 6.12 0766/1276] net/mlx5e: Fix HV VHCA stats zero-sized buffer allocation Date: Tue, 21 Jul 2026 17:20:09 +0200 Message-ID: <20260721152503.216490333@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152446.065700225@linuxfoundation.org> References: <20260721152446.065700225@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Feng Liu [ Upstream commit 25f6b929c7e379cbea7cb8caa67b49b2d1efae17 ] mlx5e_hv_vhca_stats_create() is called from mlx5e_nic_enable(), before mlx5e_open(). At that point priv->stats_nch is still zero, because it is only ever incremented in mlx5e_channel_stats_alloc(), which is reached only from mlx5e_open_channel(). mlx5e_hv_vhca_stats_buf_size() therefore returns 0, and kvzalloc(0, GFP_KERNEL) returns ZERO_SIZE_PTR ((void *)16) rather than NULL. The "if (!buf)" guard does not catch this, and mlx5e_hv_vhca_stats_create() completes "successfully" with priv->stats_agent.buf set to ZERO_SIZE_PTR. Once channels are opened (priv->stats_nch > 0) and the hypervisor enables stats reporting, mlx5e_hv_vhca_stats_work() recomputes buf_len using the new non-zero stats_nch and calls memset(buf, 0, buf_len) on ZERO_SIZE_PTR, faulting at address 0x10. Allocate the buffer based on priv->max_nch, which is set in mlx5e_priv_init() and is the upper bound on stats_nch: - Add a separate helper mlx5e_hv_vhca_stats_buf_max_size() that returns sizeof(per_ring_stats) * max(max_nch, stats_nch), and use it for the kvzalloc() in mlx5e_hv_vhca_stats_create(). - Keep mlx5e_hv_vhca_stats_buf_size() (which returns based on stats_nch) for the worker's active payload size, so the wire format (block->rings = stats_nch) and the amount of data filled by mlx5e_hv_vhca_fill_stats() are unchanged. The max(max_nch, stats_nch) guard handles the rare case where mlx5e_attach_netdev() recomputes max_nch downward across a detach/resume cycle while priv->stats_nch persists (mlx5e_detach_netdev does not call mlx5e_priv_cleanup, so stats_nch is only reset when the netdev is destroyed). Without the guard, the worker could compute buf_len from stats_nch and overrun the smaller buffer allocated based on the reduced max_nch. Allocating a non-zero buffer also makes the kvzalloc() failure path in mlx5e_hv_vhca_stats_create() reachable for the first time: it returns early without (re)creating the agent. Clear priv->stats_agent.{agent,buf} in mlx5e_hv_vhca_stats_destroy() after freeing them, so that if a later create() bails out on this path, a subsequent teardown does not double-free the stale agent/buffer left from a previous enable/disable cycle. This mirrors the existing mlx5e pattern of preallocating arrays of size max_nch (e.g. priv->channel_stats) and lazily populating entries up to stats_nch on demand. Fixes: fa691d0c9c08 ("net/mlx5e: Allocate per-channel stats dynamically at first usage") Signed-off-by: Feng Liu Reviewed-by: Eran Ben Elisha Signed-off-by: Tariq Toukan Link: https://patch.msgid.link/20260630115151.729219-2-tariqt@nvidia.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- .../net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c b/drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c index b4f3bd7d346e43..41a662d47be6f4 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c @@ -54,6 +54,12 @@ static int mlx5e_hv_vhca_stats_buf_size(struct mlx5e_priv *priv) priv->stats_nch); } +static int mlx5e_hv_vhca_stats_buf_max_size(struct mlx5e_priv *priv) +{ + return (sizeof(struct mlx5e_hv_vhca_per_ring_stats) * + max(priv->max_nch, priv->stats_nch)); +} + static void mlx5e_hv_vhca_stats_work(struct work_struct *work) { struct mlx5e_hv_vhca_stats_agent *sagent; @@ -122,7 +128,7 @@ static void mlx5e_hv_vhca_stats_cleanup(struct mlx5_hv_vhca_agent *agent) void mlx5e_hv_vhca_stats_create(struct mlx5e_priv *priv) { - int buf_len = mlx5e_hv_vhca_stats_buf_size(priv); + int buf_len = mlx5e_hv_vhca_stats_buf_max_size(priv); struct mlx5_hv_vhca_agent *agent; priv->stats_agent.buf = kvzalloc(buf_len, GFP_KERNEL); @@ -155,5 +161,7 @@ void mlx5e_hv_vhca_stats_destroy(struct mlx5e_priv *priv) return; mlx5_hv_vhca_agent_destroy(priv->stats_agent.agent); + priv->stats_agent.agent = NULL; kvfree(priv->stats_agent.buf); + priv->stats_agent.buf = NULL; } -- 2.53.0