DivestOS/Patches/Linux_CVEs/CVE-2014-9784/ANY/0.patch

From 36503d639cedcc73880974ed92132247576e72ba Mon Sep 17 00:00:00 2001
From: Sreelakshmi Gownipalli <sgownipa@codeaurora.org>
Date: Tue, 14 Jan 2014 16:54:46 -0800
Subject: diag: Fix for diag debugfs buffer overflow

Diag debugfs buffer has potential buffer overflow scenario which can cause
memory corruption. Added safeguard to prevent this.

Crs-fixed: 585147
Change-Id: Ie1f099bb4bb626adff99ae225966aef70c1bc15e
Signed-off-by: Sreelakshmi Gownipalli <sgownipa@codeaurora.org>
---
 drivers/char/diag/diag_debugfs.c | 44 +++++++++++++++++++++++++---------------
 1 file changed, 28 insertions(+), 16 deletions(-)

diff --git a/drivers/char/diag/diag_debugfs.c b/drivers/char/diag/diag_debugfs.c
index d63d34b..96c0fa0 100644
--- a/drivers/char/diag/diag_debugfs.c
+++ b/drivers/char/diag/diag_debugfs.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -33,14 +33,14 @@ static ssize_t diag_dbgfs_read_status(struct file *file, char __user *ubuf,
 {
 	char *buf;
 	int ret;
-
+	unsigned int buf_size;
 	buf = kzalloc(sizeof(char) * DEBUG_BUF_SIZE, GFP_KERNEL);
 	if (!buf) {
 		pr_err("diag: %s, Error allocating memory\n", __func__);
 		return -ENOMEM;
 	}
-
-	ret = scnprintf(buf, DEBUG_BUF_SIZE,
+	buf_size = ksize(buf);
+	ret = scnprintf(buf, buf_size,
 		"modem ch: 0x%p\n"
 		"lpass ch: 0x%p\n"
 		"riva ch: 0x%p\n"
@@ -183,7 +183,7 @@ static ssize_t diag_dbgfs_read_status(struct file *file, char __user *ubuf,
 		driver->real_time_mode);
 
 #ifdef CONFIG_DIAG_OVER_USB
-	ret += scnprintf(buf+ret, DEBUG_BUF_SIZE,
+	ret += scnprintf(buf+ret, buf_size-ret,
 		"usb_connected: %d\n",
 		driver->usb_connected);
 #endif
@@ -200,7 +200,8 @@ static ssize_t diag_dbgfs_read_dcistats(struct file *file,
 	unsigned int bytes_remaining, bytes_written = 0;
 	unsigned int bytes_in_buf = 0, i = 0;
 	struct diag_dci_data_info *temp_data = dci_data_smd;
-	int buf_size = (DEBUG_BUF_SIZE < count) ? DEBUG_BUF_SIZE : count;
+	unsigned int buf_size;
+	buf_size = (DEBUG_BUF_SIZE < count) ? DEBUG_BUF_SIZE : count;
 
 	if (diag_dbgfs_dci_finished) {
 		diag_dbgfs_dci_finished = 0;
@@ -213,6 +214,7 @@ static ssize_t diag_dbgfs_read_dcistats(struct file *file,
 		return -ENOMEM;
 	}
 
+	buf_size = ksize(buf);
 	bytes_remaining = buf_size;
 
 	if (diag_dbgfs_dci_data_index == 0) {
@@ -281,6 +283,7 @@ static ssize_t diag_dbgfs_read_workpending(struct file *file,
 {
 	char *buf;
 	int ret;
+	unsigned int buf_size;
 
 	buf = kzalloc(sizeof(char) * DEBUG_BUF_SIZE, GFP_KERNEL);
 	if (!buf) {
@@ -288,7 +291,8 @@ static ssize_t diag_dbgfs_read_workpending(struct file *file,
 		return -ENOMEM;
 	}
 
-	ret = scnprintf(buf, DEBUG_BUF_SIZE,
+	buf_size = ksize(buf);
+	ret = scnprintf(buf, buf_size,
 		"Pending status for work_stucts:\n"
 		"diag_drain_work: %d\n"
 		"Modem data diag_read_smd_work: %d\n"
@@ -336,7 +340,7 @@ static ssize_t diag_dbgfs_read_workpending(struct file *file,
 						diag_notify_update_smd_work)));
 
 #ifdef CONFIG_DIAG_OVER_USB
-	ret += scnprintf(buf+ret, DEBUG_BUF_SIZE,
+	ret += scnprintf(buf+ret, buf_size-ret,
 		"diag_proc_hdlc_work: %d\n"
 		"diag_read_work: %d\n",
 		work_pending(&(driver->diag_proc_hdlc_work)),
@@ -357,7 +361,8 @@ static ssize_t diag_dbgfs_read_table(struct file *file, char __user *ubuf,
 	unsigned int bytes_remaining;
 	unsigned int bytes_in_buffer = 0;
 	unsigned int bytes_written;
-	int buf_size = (DEBUG_BUF_SIZE < count) ? DEBUG_BUF_SIZE : count;
+	unsigned int buf_size;
+	buf_size = (DEBUG_BUF_SIZE < count) ? DEBUG_BUF_SIZE : count;
 
 	if (diag_dbgfs_table_index >= diag_max_reg) {
 		/* Done. Reset to prepare for future requests */
@@ -370,7 +375,7 @@ static ssize_t diag_dbgfs_read_table(struct file *file, char __user *ubuf,
 		pr_err("diag: %s, Error allocating memory\n", __func__);
 		return -ENOMEM;
 	}
-
+	buf_size = ksize(buf);
 	bytes_remaining = buf_size;
 
 	if (diag_dbgfs_table_index == 0) {
@@ -379,6 +384,7 @@ static ssize_t diag_dbgfs_read_table(struct file *file, char __user *ubuf,
 			"WCNSS: %d, APPS: %d\n",
 			MODEM_DATA, LPASS_DATA, WCNSS_DATA, APPS_DATA);
 		bytes_in_buffer += bytes_written;
+		bytes_remaining -= bytes_written;
 	}
 
 	for (i = diag_dbgfs_table_index; i < diag_max_reg; i++) {
@@ -422,14 +428,15 @@ static ssize_t diag_dbgfs_read_mempool(struct file *file, char __user *ubuf,
 {
 	char *buf = NULL;
 	int ret = 0, i = 0;
-
+	unsigned int buf_size;
 	buf = kzalloc(sizeof(char) * DEBUG_BUF_SIZE, GFP_KERNEL);
 	if (ZERO_OR_NULL_PTR(buf)) {
 		pr_err("diag: %s, Error allocating memory\n", __func__);
 		return -ENOMEM;
 	}
+	buf_size = ksize(buf);
 
-	ret = scnprintf(buf, DEBUG_BUF_SIZE,
+	ret = scnprintf(buf, buf_size,
 		"POOL_TYPE_COPY: [0x%p : 0x%p] count = %d\n"
 		"POOL_TYPE_HDLC: [0x%p : 0x%p] count = %d\n"
 		"POOL_TYPE_USER: [0x%p : 0x%p] count = %d\n"
@@ -454,7 +461,7 @@ static ssize_t diag_dbgfs_read_mempool(struct file *file, char __user *ubuf,
 	for (i = 0; i < MAX_HSIC_CH; i++) {
 		if (!diag_hsic[i].hsic_inited)
 			continue;
-		ret += scnprintf(buf+ret, DEBUG_BUF_SIZE-ret,
+		ret += scnprintf(buf+ret, buf_size-ret,
 				"POOL_TYPE_HSIC_%d: [0x%p : 0x%p] count = %d\n",
 				i+1,
 				diag_hsic[i].diag_hsic_pool,
@@ -465,7 +472,7 @@ static ssize_t diag_dbgfs_read_mempool(struct file *file, char __user *ubuf,
 	for (i = 0; i < MAX_HSIC_CH; i++) {
 		if (!diag_hsic[i].hsic_inited)
 			continue;
-		ret += scnprintf(buf+ret, DEBUG_BUF_SIZE-ret,
+		ret += scnprintf(buf+ret, buf_size-ret,
 				"POOL_TYPE_HSIC_%d_WRITE: [0x%p : 0x%p] count = %d\n",
 				i+1,
 				diag_hsic[i].diag_hsic_write_pool,
@@ -484,6 +491,7 @@ static ssize_t diag_dbgfs_read_mempool(struct file *file, char __user *ubuf,
 {
 	char *buf = NULL;
 	int ret = 0;
+	unsigned int buf_size;
 
 	buf = kzalloc(sizeof(char) * DEBUG_BUF_SIZE, GFP_KERNEL);
 	if (ZERO_OR_NULL_PTR(buf)) {
@@ -491,7 +499,8 @@ static ssize_t diag_dbgfs_read_mempool(struct file *file, char __user *ubuf,
 		return -ENOMEM;
 	}
 
-	ret = scnprintf(buf, DEBUG_BUF_SIZE,
+	buf_size = ksize(buf);
+	ret = scnprintf(buf, buf_size,
 		"POOL_TYPE_COPY: [0x%p : 0x%p] count = %d\n"
 		"POOL_TYPE_HDLC: [0x%p : 0x%p] count = %d\n"
 		"POOL_TYPE_USER: [0x%p : 0x%p] count = %d\n"
@@ -530,10 +539,12 @@ static ssize_t diag_dbgfs_read_bridge(struct file *file, char __user *ubuf,
 	unsigned int bytes_remaining;
 	unsigned int bytes_in_buffer = 0;
 	unsigned int bytes_written;
-	int buf_size = (DEBUG_BUF_SIZE < count) ? DEBUG_BUF_SIZE : count;
+	unsigned int buf_size;
 	int bytes_hsic_inited = 45;
 	int bytes_hsic_not_inited = 410;
 
+	buf_size = (DEBUG_BUF_SIZE < count) ? DEBUG_BUF_SIZE : count;
+
 	if (diag_dbgfs_finished) {
 		diag_dbgfs_finished = 0;
 		return 0;
@@ -545,6 +556,7 @@ static ssize_t diag_dbgfs_read_bridge(struct file *file, char __user *ubuf,
 		return -ENOMEM;
 	}
 
+	buf_size = ksize(buf);
 	bytes_remaining = buf_size;
 
 	/* Only one smux for now */
-- 
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