linux/sound/pci/ctxfi/ctresource.c
Takashi Iwai 76c4718322 ALSA: ctxfi: Fix out-of-range access
The master and next_conj of rcs_ops are used for iterating the
resource list entries, and currently those are supposed to return the
current value.  The problem is that next_conf may go over the last
entry before the loop abort condition is evaluated, and it may return
the "current" value that is beyond the array size.  It was caught
recently as a GPF, for example.

Those return values are, however, never actually evaluated, hence
basically we don't have to consider the current value as the return at
all.  By dropping those return values, the potential out-of-range
access above is also fixed automatically.

This patch changes the return type of master and next_conj callbacks
to void and drop the superfluous code accordingly.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=214985
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211118215729.26257-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-11-18 22:57:55 +01:00

290 lines
5.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved.
*
* @File ctresource.c
*
* @Brief
* This file contains the implementation of some generic helper functions.
*
* @Author Liu Chun
* @Date May 15 2008
*/
#include "ctresource.h"
#include "cthardware.h"
#include <linux/err.h>
#include <linux/slab.h>
#define AUDIO_SLOT_BLOCK_NUM 256
/* Resource allocation based on bit-map management mechanism */
static int
get_resource(u8 *rscs, unsigned int amount,
unsigned int multi, unsigned int *ridx)
{
int i, j, k, n;
/* Check whether there are sufficient resources to meet request. */
for (i = 0, n = multi; i < amount; i++) {
j = i / 8;
k = i % 8;
if (rscs[j] & ((u8)1 << k)) {
n = multi;
continue;
}
if (!(--n))
break; /* found sufficient contiguous resources */
}
if (i >= amount) {
/* Can not find sufficient contiguous resources */
return -ENOENT;
}
/* Mark the contiguous bits in resource bit-map as used */
for (n = multi; n > 0; n--) {
j = i / 8;
k = i % 8;
rscs[j] |= ((u8)1 << k);
i--;
}
*ridx = i + 1;
return 0;
}
static int put_resource(u8 *rscs, unsigned int multi, unsigned int idx)
{
unsigned int i, j, k, n;
/* Mark the contiguous bits in resource bit-map as used */
for (n = multi, i = idx; n > 0; n--) {
j = i / 8;
k = i % 8;
rscs[j] &= ~((u8)1 << k);
i++;
}
return 0;
}
int mgr_get_resource(struct rsc_mgr *mgr, unsigned int n, unsigned int *ridx)
{
int err;
if (n > mgr->avail)
return -ENOENT;
err = get_resource(mgr->rscs, mgr->amount, n, ridx);
if (!err)
mgr->avail -= n;
return err;
}
int mgr_put_resource(struct rsc_mgr *mgr, unsigned int n, unsigned int idx)
{
put_resource(mgr->rscs, n, idx);
mgr->avail += n;
return 0;
}
static const unsigned char offset_in_audio_slot_block[NUM_RSCTYP] = {
/* SRC channel is at Audio Ring slot 1 every 16 slots. */
[SRC] = 0x1,
[AMIXER] = 0x4,
[SUM] = 0xc,
};
static int rsc_index(const struct rsc *rsc)
{
return rsc->conj;
}
static int audio_ring_slot(const struct rsc *rsc)
{
return (rsc->conj << 4) + offset_in_audio_slot_block[rsc->type];
}
static void rsc_next_conj(struct rsc *rsc)
{
unsigned int i;
for (i = 0; (i < 8) && (!(rsc->msr & (0x1 << i))); )
i++;
rsc->conj += (AUDIO_SLOT_BLOCK_NUM >> i);
}
static void rsc_master(struct rsc *rsc)
{
rsc->conj = rsc->idx;
}
static const struct rsc_ops rsc_generic_ops = {
.index = rsc_index,
.output_slot = audio_ring_slot,
.master = rsc_master,
.next_conj = rsc_next_conj,
};
int
rsc_init(struct rsc *rsc, u32 idx, enum RSCTYP type, u32 msr, struct hw *hw)
{
int err = 0;
rsc->idx = idx;
rsc->conj = idx;
rsc->type = type;
rsc->msr = msr;
rsc->hw = hw;
rsc->ops = &rsc_generic_ops;
if (!hw) {
rsc->ctrl_blk = NULL;
return 0;
}
switch (type) {
case SRC:
err = hw->src_rsc_get_ctrl_blk(&rsc->ctrl_blk);
break;
case AMIXER:
err = hw->amixer_rsc_get_ctrl_blk(&rsc->ctrl_blk);
break;
case SRCIMP:
case SUM:
case DAIO:
break;
default:
dev_err(((struct hw *)hw)->card->dev,
"Invalid resource type value %d!\n", type);
return -EINVAL;
}
if (err) {
dev_err(((struct hw *)hw)->card->dev,
"Failed to get resource control block!\n");
return err;
}
return 0;
}
int rsc_uninit(struct rsc *rsc)
{
if ((NULL != rsc->hw) && (NULL != rsc->ctrl_blk)) {
switch (rsc->type) {
case SRC:
rsc->hw->src_rsc_put_ctrl_blk(rsc->ctrl_blk);
break;
case AMIXER:
rsc->hw->amixer_rsc_put_ctrl_blk(rsc->ctrl_blk);
break;
case SUM:
case DAIO:
break;
default:
dev_err(((struct hw *)rsc->hw)->card->dev,
"Invalid resource type value %d!\n",
rsc->type);
break;
}
rsc->hw = rsc->ctrl_blk = NULL;
}
rsc->idx = rsc->conj = 0;
rsc->type = NUM_RSCTYP;
rsc->msr = 0;
return 0;
}
int rsc_mgr_init(struct rsc_mgr *mgr, enum RSCTYP type,
unsigned int amount, struct hw *hw)
{
int err = 0;
mgr->type = NUM_RSCTYP;
mgr->rscs = kzalloc(DIV_ROUND_UP(amount, 8), GFP_KERNEL);
if (!mgr->rscs)
return -ENOMEM;
switch (type) {
case SRC:
err = hw->src_mgr_get_ctrl_blk(&mgr->ctrl_blk);
break;
case SRCIMP:
err = hw->srcimp_mgr_get_ctrl_blk(&mgr->ctrl_blk);
break;
case AMIXER:
err = hw->amixer_mgr_get_ctrl_blk(&mgr->ctrl_blk);
break;
case DAIO:
err = hw->daio_mgr_get_ctrl_blk(hw, &mgr->ctrl_blk);
break;
case SUM:
break;
default:
dev_err(hw->card->dev,
"Invalid resource type value %d!\n", type);
err = -EINVAL;
goto error;
}
if (err) {
dev_err(hw->card->dev,
"Failed to get manager control block!\n");
goto error;
}
mgr->type = type;
mgr->avail = mgr->amount = amount;
mgr->hw = hw;
return 0;
error:
kfree(mgr->rscs);
return err;
}
int rsc_mgr_uninit(struct rsc_mgr *mgr)
{
kfree(mgr->rscs);
mgr->rscs = NULL;
if ((NULL != mgr->hw) && (NULL != mgr->ctrl_blk)) {
switch (mgr->type) {
case SRC:
mgr->hw->src_mgr_put_ctrl_blk(mgr->ctrl_blk);
break;
case SRCIMP:
mgr->hw->srcimp_mgr_put_ctrl_blk(mgr->ctrl_blk);
break;
case AMIXER:
mgr->hw->amixer_mgr_put_ctrl_blk(mgr->ctrl_blk);
break;
case DAIO:
mgr->hw->daio_mgr_put_ctrl_blk(mgr->ctrl_blk);
break;
case SUM:
break;
default:
dev_err(((struct hw *)mgr->hw)->card->dev,
"Invalid resource type value %d!\n",
mgr->type);
break;
}
mgr->hw = mgr->ctrl_blk = NULL;
}
mgr->type = NUM_RSCTYP;
mgr->avail = mgr->amount = 0;
return 0;
}