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Revision 9c1c2b35f1d94de8325344c2777d7ee67492db3b authored by Jeff Layton on 03 April 2019, 17:16:01 UTC, committed by Ilya Dryomov on 21 January 2020, 18:02:37 UTC 
ceph: hold extra reference to r_parent over life of request
 
Currently, we just assume that it will stick around by virtue of the
submitter's reference, but later patches will allow the syscall to
return early and we can't rely on that reference at that point.

While I'm not aware of any reports of it, Xiubo pointed out that this
may fix a use-after-free.  If the wait for a reply times out or is
canceled via signal, and then the reply comes in after the syscall
returns, the client can end up trying to access r_parent without a
reference.

Take an extra reference to the inode when setting r_parent and release
it when releasing the request.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
1 parent def9d27
Raw File
internal.h 
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Cryptographic API.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
 */
#ifndef _CRYPTO_INTERNAL_H
#define _CRYPTO_INTERNAL_H

#include <crypto/algapi.h>
#include <linux/completion.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/notifier.h>
#include <linux/rwsem.h>
#include <linux/slab.h>

struct crypto_instance;
struct crypto_template;

struct crypto_larval {
	struct crypto_alg alg;
	struct crypto_alg *adult;
	struct completion completion;
	u32 mask;
};

extern struct list_head crypto_alg_list;
extern struct rw_semaphore crypto_alg_sem;
extern struct blocking_notifier_head crypto_chain;

#ifdef CONFIG_PROC_FS
void __init crypto_init_proc(void);
void __exit crypto_exit_proc(void);
#else
static inline void crypto_init_proc(void)
{ }
static inline void crypto_exit_proc(void)
{ }
#endif

static inline unsigned int crypto_cipher_ctxsize(struct crypto_alg *alg)
{
	return alg->cra_ctxsize;
}

static inline unsigned int crypto_compress_ctxsize(struct crypto_alg *alg)
{
	return alg->cra_ctxsize;
}

struct crypto_alg *crypto_mod_get(struct crypto_alg *alg);
struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask);

int crypto_init_cipher_ops(struct crypto_tfm *tfm);
int crypto_init_compress_ops(struct crypto_tfm *tfm);

struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask);
void crypto_larval_kill(struct crypto_alg *alg);
void crypto_alg_tested(const char *name, int err);

void crypto_remove_spawns(struct crypto_alg *alg, struct list_head *list,
			  struct crypto_alg *nalg);
void crypto_remove_final(struct list_head *list);
void crypto_shoot_alg(struct crypto_alg *alg);
struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
				      u32 mask);
void *crypto_create_tfm(struct crypto_alg *alg,
			const struct crypto_type *frontend);
struct crypto_alg *crypto_find_alg(const char *alg_name,
				   const struct crypto_type *frontend,
				   u32 type, u32 mask);
void *crypto_alloc_tfm(const char *alg_name,
		       const struct crypto_type *frontend, u32 type, u32 mask);

int crypto_probing_notify(unsigned long val, void *v);

unsigned int crypto_alg_extsize(struct crypto_alg *alg);

int crypto_type_has_alg(const char *name, const struct crypto_type *frontend,
			u32 type, u32 mask);

static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
{
	refcount_inc(&alg->cra_refcnt);
	return alg;
}

static inline void crypto_alg_put(struct crypto_alg *alg)
{
	if (refcount_dec_and_test(&alg->cra_refcnt) && alg->cra_destroy)
		alg->cra_destroy(alg);
}

static inline int crypto_tmpl_get(struct crypto_template *tmpl)
{
	return try_module_get(tmpl->module);
}

static inline void crypto_tmpl_put(struct crypto_template *tmpl)
{
	module_put(tmpl->module);
}

static inline int crypto_is_larval(struct crypto_alg *alg)
{
	return alg->cra_flags & CRYPTO_ALG_LARVAL;
}

static inline int crypto_is_dead(struct crypto_alg *alg)
{
	return alg->cra_flags & CRYPTO_ALG_DEAD;
}

static inline int crypto_is_moribund(struct crypto_alg *alg)
{
	return alg->cra_flags & (CRYPTO_ALG_DEAD | CRYPTO_ALG_DYING);
}

static inline void crypto_notify(unsigned long val, void *v)
{
	blocking_notifier_call_chain(&crypto_chain, val, v);
}

#endif	/* _CRYPTO_INTERNAL_H */
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