Commit 0fa10472 authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

net, sunrpc: convert gss_cl_ctx.count from atomic_t to refcount_t



refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: default avatarElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: default avatarHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarDavid Windsor <dwindsor@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 156be7ed
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+2 −1
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@
#define _LINUX_SUNRPC_AUTH_GSS_H

#ifdef __KERNEL__
#include <linux/refcount.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/gss_api.h>
@@ -65,7 +66,7 @@ struct rpc_gss_init_res {
 * the wire when communicating with a server. */

struct gss_cl_ctx {
	atomic_t		count;
	refcount_t		count;
	enum rpc_gss_proc	gc_proc;
	u32			gc_seq;
	spinlock_t		gc_seq_lock;
+3 −3
Original line number Diff line number Diff line
@@ -117,14 +117,14 @@ static const struct rpc_pipe_ops gss_upcall_ops_v1;
static inline struct gss_cl_ctx *
gss_get_ctx(struct gss_cl_ctx *ctx)
{
	atomic_inc(&ctx->count);
	refcount_inc(&ctx->count);
	return ctx;
}

static inline void
gss_put_ctx(struct gss_cl_ctx *ctx)
{
	if (atomic_dec_and_test(&ctx->count))
	if (refcount_dec_and_test(&ctx->count))
		gss_free_ctx(ctx);
}

@@ -200,7 +200,7 @@ gss_alloc_context(void)
		ctx->gc_proc = RPC_GSS_PROC_DATA;
		ctx->gc_seq = 1;	/* NetApp 6.4R1 doesn't accept seq. no. 0 */
		spin_lock_init(&ctx->gc_seq_lock);
		atomic_set(&ctx->count,1);
		refcount_set(&ctx->count,1);
	}
	return ctx;
}