From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 36B46225A38; Mon, 13 Apr 2026 16:30:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776097806; cv=none; b=qJnzjElJcPt6shV/wlWIY0Fgp+YKGgB+TI/M3iLqbdLa6gfZnIPujt3LhiNJXuy9S2+sDQAsUfDxd3jAC+wiONHkvssaeuKJyIjxZSZ+lgd7P1rZEkTYykoRqzvU9546O5fwkSnPAC1PsT+OBOwAzWgoOfRDP29ioLqS4TomJXc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776097806; c=relaxed/simple; bh=lJmQHyxpVXxuRn613MJn6lHoRlLE7HpLjncFwTQlmb0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ndleGqqDox90J2wZHQfEmMa9BUmhZ5TrXbzgNlNsEd1ryrIcRub8sjsQMdaSAJhq+4H2IGmT1wM8klATfw++7289NTBMu/QNgCnVwXauCsC8LpGmumVfdLkAjZwk1j9bhYdkCJ/YMclHQ43RUG+bN4N2f/PMGk1jjxaMOOm7PHk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XH2PwOtw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="XH2PwOtw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0F31C2BCAF; Mon, 13 Apr 2026 16:30:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776097806; bh=lJmQHyxpVXxuRn613MJn6lHoRlLE7HpLjncFwTQlmb0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XH2PwOtw4sHSYHyJRetzH7AXgcmP3km9stciMQZYriBoEsji4qXwPrl5bA/j/ZsmX f5vRaGQWDK3/SfgPV9txuby2iyJhP3glEMKSM/ftknB04LARYOj7zVuYeA+lWqW6IS Er4fzgrEak2Fc3bS+Wr9w7IexoqI3OrFKgNhrfow= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Muhammad Hammad Ijaz , Gunnar Kudrjavets , Paolo Abeni , Sasha Levin Subject: [PATCH 5.15 280/570] net: mvpp2: guard flow control update with global_tx_fc in buffer switching Date: Mon, 13 Apr 2026 17:56:51 +0200 Message-ID: <20260413155840.978704808@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155830.386096114@linuxfoundation.org> References: <20260413155830.386096114@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Muhammad Hammad Ijaz [ Upstream commit 8a63baadf08453f66eb582fdb6dd234f72024723 ] mvpp2_bm_switch_buffers() unconditionally calls mvpp2_bm_pool_update_priv_fc() when switching between per-cpu and shared buffer pool modes. This function programs CM3 flow control registers via mvpp2_cm3_read()/mvpp2_cm3_write(), which dereference priv->cm3_base without any NULL check. When the CM3 SRAM resource is not present in the device tree (the third reg entry added by commit 60523583b07c ("dts: marvell: add CM3 SRAM memory to cp11x ethernet device tree")), priv->cm3_base remains NULL and priv->global_tx_fc is false. Any operation that triggers mvpp2_bm_switch_buffers(), for example an MTU change that crosses the jumbo frame threshold, will crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Mem abort info: ESR = 0x0000000096000006 EC = 0x25: DABT (current EL), IL = 32 bits pc : readl+0x0/0x18 lr : mvpp2_cm3_read.isra.0+0x14/0x20 Call trace: readl+0x0/0x18 mvpp2_bm_pool_update_fc+0x40/0x12c mvpp2_bm_pool_update_priv_fc+0x94/0xd8 mvpp2_bm_switch_buffers.isra.0+0x80/0x1c0 mvpp2_change_mtu+0x140/0x380 __dev_set_mtu+0x1c/0x38 dev_set_mtu_ext+0x78/0x118 dev_set_mtu+0x48/0xa8 dev_ifsioc+0x21c/0x43c dev_ioctl+0x2d8/0x42c sock_ioctl+0x314/0x378 Every other flow control call site in the driver already guards hardware access with either priv->global_tx_fc or port->tx_fc. mvpp2_bm_switch_buffers() is the only place that omits this check. Add the missing priv->global_tx_fc guard to both the disable and re-enable calls in mvpp2_bm_switch_buffers(), consistent with the rest of the driver. Fixes: 3a616b92a9d1 ("net: mvpp2: Add TX flow control support for jumbo frames") Signed-off-by: Muhammad Hammad Ijaz Reviewed-by: Gunnar Kudrjavets Link: https://patch.msgid.link/20260316193157.65748-1-mhijaz@amazon.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 7fa880e62d096..fdfdd55fdb1dc 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -5006,7 +5006,7 @@ static int mvpp2_bm_switch_buffers(struct mvpp2 *priv, bool percpu) if (priv->percpu_pools) numbufs = port->nrxqs * 2; - if (change_percpu) + if (change_percpu && priv->global_tx_fc) mvpp2_bm_pool_update_priv_fc(priv, false); for (i = 0; i < numbufs; i++) @@ -5023,7 +5023,7 @@ static int mvpp2_bm_switch_buffers(struct mvpp2 *priv, bool percpu) mvpp2_open(port->dev); } - if (change_percpu) + if (change_percpu && priv->global_tx_fc) mvpp2_bm_pool_update_priv_fc(priv, true); return 0; -- 2.51.0