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linux/sound/pci/ctxfi/ctresource.h
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

70 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved.
*
* @File ctresource.h
*
* @Brief
* This file contains the definition of generic hardware resources for
* resource management.
*
* @Author Liu Chun
* @Date May 13 2008
*/
#ifndef CTRESOURCE_H
#define CTRESOURCE_H
#include <linux/types.h>
enum RSCTYP {
SRC,
SRCIMP,
AMIXER,
SUM,
DAIO,
NUM_RSCTYP /* This must be the last one and less than 16 */
};
struct rsc_ops;
struct rsc {
u32 idx:12; /* The index of a resource */
u32 type:4; /* The type (RSCTYP) of a resource */
u32 conj:12; /* Current conjugate index */
u32 msr:4; /* The Master Sample Rate a resource working on */
void *ctrl_blk; /* Chip specific control info block for a resource */
struct hw *hw; /* Chip specific object for hardware access means */
const struct rsc_ops *ops; /* Generic resource operations */
};
struct rsc_ops {
void (*master)(struct rsc *rsc); /* Move to master resource */
void (*next_conj)(struct rsc *rsc); /* Move to next conjugate resource */
int (*index)(const struct rsc *rsc); /* Return the index of resource */
/* Return the output slot number */
int (*output_slot)(const struct rsc *rsc);
};
int
rsc_init(struct rsc *rsc, u32 idx, enum RSCTYP type, u32 msr, struct hw *hw);
int rsc_uninit(struct rsc *rsc);
struct rsc_mgr {
enum RSCTYP type; /* The type (RSCTYP) of resource to manage */
unsigned int amount; /* The total amount of a kind of resource */
unsigned int avail; /* The amount of currently available resources */
unsigned char *rscs; /* The bit-map for resource allocation */
void *ctrl_blk; /* Chip specific control info block */
struct hw *hw; /* Chip specific object for hardware access */
};
/* Resource management is based on bit-map mechanism */
int rsc_mgr_init(struct rsc_mgr *mgr, enum RSCTYP type,
unsigned int amount, struct hw *hw);
int rsc_mgr_uninit(struct rsc_mgr *mgr);
int mgr_get_resource(struct rsc_mgr *mgr, unsigned int n, unsigned int *ridx);
int mgr_put_resource(struct rsc_mgr *mgr, unsigned int n, unsigned int idx);
#endif /* CTRESOURCE_H */