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linux-next/sound/firewire/packets-buffer.c
Wenwen Wang 1be3c1fae6 ALSA: firewire: fix a memory leak bug
In iso_packets_buffer_init(), 'b->packets' is allocated through
kmalloc_array(). Then, the aligned packet size is checked. If it is
larger than PAGE_SIZE, -EINVAL will be returned to indicate the error.
However, the allocated 'b->packets' is not deallocated on this path,
leading to a memory leak.

To fix the above issue, free 'b->packets' before returning the error code.

Fixes: 31ef9134eb ("ALSA: add LaCie FireWire Speakers/Griffin FireWave Surround driver")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: <stable@vger.kernel.org> # v2.6.39+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-08-08 11:12:26 +02:00

78 lines
2.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* helpers for managing a buffer for many packets
*
* Copyright (c) Clemens Ladisch <clemens@ladisch.de>
*/
#include <linux/firewire.h>
#include <linux/export.h>
#include <linux/slab.h>
#include "packets-buffer.h"
/**
* iso_packets_buffer_init - allocates the memory for packets
* @b: the buffer structure to initialize
* @unit: the device at the other end of the stream
* @count: the number of packets
* @packet_size: the (maximum) size of a packet, in bytes
* @direction: %DMA_TO_DEVICE or %DMA_FROM_DEVICE
*/
int iso_packets_buffer_init(struct iso_packets_buffer *b, struct fw_unit *unit,
unsigned int count, unsigned int packet_size,
enum dma_data_direction direction)
{
unsigned int packets_per_page, pages;
unsigned int i, page_index, offset_in_page;
void *p;
int err;
b->packets = kmalloc_array(count, sizeof(*b->packets), GFP_KERNEL);
if (!b->packets) {
err = -ENOMEM;
goto error;
}
packet_size = L1_CACHE_ALIGN(packet_size);
packets_per_page = PAGE_SIZE / packet_size;
if (WARN_ON(!packets_per_page)) {
err = -EINVAL;
goto err_packets;
}
pages = DIV_ROUND_UP(count, packets_per_page);
err = fw_iso_buffer_init(&b->iso_buffer, fw_parent_device(unit)->card,
pages, direction);
if (err < 0)
goto err_packets;
for (i = 0; i < count; ++i) {
page_index = i / packets_per_page;
p = page_address(b->iso_buffer.pages[page_index]);
offset_in_page = (i % packets_per_page) * packet_size;
b->packets[i].buffer = p + offset_in_page;
b->packets[i].offset = page_index * PAGE_SIZE + offset_in_page;
}
return 0;
err_packets:
kfree(b->packets);
error:
return err;
}
EXPORT_SYMBOL(iso_packets_buffer_init);
/**
* iso_packets_buffer_destroy - frees packet buffer resources
* @b: the buffer structure to free
* @unit: the device at the other end of the stream
*/
void iso_packets_buffer_destroy(struct iso_packets_buffer *b,
struct fw_unit *unit)
{
fw_iso_buffer_destroy(&b->iso_buffer, fw_parent_device(unit)->card);
kfree(b->packets);
}
EXPORT_SYMBOL(iso_packets_buffer_destroy);