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 5471C3568FE; Tue, 26 Aug 2025 14:29:35 +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=1756218575; cv=none; b=RrPNWAawVj4HDk4z34tqx3sxXpwDM4Xh+zgd7n2JnGvDotXkQCnvu5s6j6Qx7Wtfvpi0RHIylFa5+UvZoyHzuFjKIBYmkm16MV+q9i1aBAqPKQEk+cKqrk783ifUtnnBO9FWhwgWiu49OQW4Ia7dGfbq/bltqAL78VCCwCxI2Gg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756218575; c=relaxed/simple; bh=y4Fwbne41NXQZOhSOrf9ddM1uIZjof9v1QRdcNGLhXc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=usVrOw8bCG13/B0iqor8W+hgCjNfewPp9HVDQCynA9FQlvWnCJyK/IOeXLubgls7oW0ZGPPp712wn1uRcJwPXFEv7aknXLwjzF5Y8OWm1QLYWWzh+DGNLztCleqlngHrMWTzv4N4FrEVKPiBny7gQQHcI/G6uIjx0xgpHfyANGE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UocmXRkz; 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="UocmXRkz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9DE22C4CEF1; Tue, 26 Aug 2025 14:29:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756218575; bh=y4Fwbne41NXQZOhSOrf9ddM1uIZjof9v1QRdcNGLhXc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UocmXRkz4rX6OJg7KhGZlvJH313NkWBKO/Soft2bToYbd7JqLZ66sOZwoPZt6JMN8 q1l0tPltKBbs6rKglTJ3he6eL9onzDBty3q9yuyrKJhVJZsgZZd+y3btLqw1M17bz5 Zyfl7adasCCCX3hGtR2BKkLAjsVUbp0llamnyoEg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jean Delvare , Andrew Jeffery Subject: [PATCH 5.4 021/403] soc: aspeed: lpc-snoop: Dont disable channels that arent enabled Date: Tue, 26 Aug 2025 13:05:47 +0200 Message-ID: <20250826110906.353598189@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110905.607690791@linuxfoundation.org> References: <20250826110905.607690791@linuxfoundation.org> User-Agent: quilt/0.68 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 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Jeffery commit 56448e78a6bb4e1a8528a0e2efe94eff0400c247 upstream. Mitigate e.g. the following: # echo 1e789080.lpc-snoop > /sys/bus/platform/drivers/aspeed-lpc-snoop/unbind ... [ 120.363594] Unable to handle kernel NULL pointer dereference at virtual address 00000004 when write [ 120.373866] [00000004] *pgd=00000000 [ 120.377910] Internal error: Oops: 805 [#1] SMP ARM [ 120.383306] CPU: 1 UID: 0 PID: 315 Comm: sh Not tainted 6.15.0-rc1-00009-g926217bc7d7d-dirty #20 NONE ... [ 120.679543] Call trace: [ 120.679559] misc_deregister from aspeed_lpc_snoop_remove+0x84/0xac [ 120.692462] aspeed_lpc_snoop_remove from platform_remove+0x28/0x38 [ 120.700996] platform_remove from device_release_driver_internal+0x188/0x200 ... Fixes: 9f4f9ae81d0a ("drivers/misc: add Aspeed LPC snoop driver") Cc: stable@vger.kernel.org Cc: Jean Delvare Acked-by: Jean Delvare Link: https://patch.msgid.link/20250616-aspeed-lpc-snoop-fixes-v2-2-3cdd59c934d3@codeconstruct.com.au Signed-off-by: Andrew Jeffery Signed-off-by: Greg Kroah-Hartman --- drivers/soc/aspeed/aspeed-lpc-snoop.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c @@ -60,6 +60,7 @@ struct aspeed_lpc_snoop_model_data { }; struct aspeed_lpc_snoop_channel { + bool enabled; struct kfifo fifo; wait_queue_head_t wq; struct miscdevice miscdev; @@ -192,6 +193,9 @@ static int aspeed_lpc_enable_snoop(struc const struct aspeed_lpc_snoop_model_data *model_data = of_device_get_match_data(dev); + if (WARN_ON(lpc_snoop->chan[channel].enabled)) + return -EBUSY; + init_waitqueue_head(&lpc_snoop->chan[channel].wq); /* Create FIFO datastructure */ rc = kfifo_alloc(&lpc_snoop->chan[channel].fifo, @@ -238,6 +242,8 @@ static int aspeed_lpc_enable_snoop(struc regmap_update_bits(lpc_snoop->regmap, HICRB, hicrb_en, hicrb_en); + lpc_snoop->chan[channel].enabled = true; + return 0; err_misc_deregister: @@ -250,6 +256,9 @@ err_free_fifo: static void aspeed_lpc_disable_snoop(struct aspeed_lpc_snoop *lpc_snoop, int channel) { + if (!lpc_snoop->chan[channel].enabled) + return; + switch (channel) { case 0: regmap_update_bits(lpc_snoop->regmap, HICR5, @@ -265,6 +274,8 @@ static void aspeed_lpc_disable_snoop(str return; } + lpc_snoop->chan[channel].enabled = false; + /* Consider improving safety wrt concurrent reader(s) */ misc_deregister(&lpc_snoop->chan[channel].miscdev); kfifo_free(&lpc_snoop->chan[channel].fifo); }