sunrpc: convert to time64_t for expiry

mainline inclusion
from mainline-v5.6-rc1
commit 294ec5b8
category: bugfix
bugzilla: 51810
CVE: NA

-------------------------------------------------

Using signed 32-bit types for UTC time leads to the y2038 overflow,
which is what happens in the sunrpc code at the moment.

This changes the sunrpc code over to use time64_t where possible.
The one exception is the gss_import_v{1,2}_context() function for
kerberos5, which uses 32-bit timestamps in the protocol. Here,
we can at least treat the numbers as 'unsigned', which extends the
range from 2038 to 2106.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLu Wei <luwei32@huawei.com>
Reviewed-by: NYue Haibing <yuehaibing@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

include/linux/sunrpc/gss_api.h

@@ -49,7 +49,7 @@ int gss_import_sec_context(
 		size_t			bufsize,
 		struct gss_api_mech	*mech,
 		struct gss_ctx		**ctx_id,
-		time_t			*endtime,
+		time64_t		*endtime,
 		gfp_t			gfp_mask);
 u32 gss_get_mic(
 		struct gss_ctx		*ctx_id,
@@ -110,7 +110,7 @@ struct gss_api_ops {
 			const void		*input_token,
 			size_t			bufsize,
 			struct gss_ctx		*ctx_id,
-			time_t			*endtime,
+			time64_t		*endtime,
 			gfp_t			gfp_mask);
 	u32 (*gss_get_mic)(
 			struct gss_ctx		*ctx_id,

include/linux/sunrpc/gss_krb5.h

@@ -106,7 +106,7 @@ struct krb5_ctx {
 	struct crypto_skcipher *initiator_enc_aux;
 	u8			Ksess[GSS_KRB5_MAX_KEYLEN]; /* session key */
 	u8			cksum[GSS_KRB5_MAX_KEYLEN];
-	s32			endtime;
+	time64_t		endtime;
 	u32			seq_send;
 	u64			seq_send64;
 	struct xdr_netobj	mech_used;

net/sunrpc/auth_gss/gss_krb5_mech.c

@@ -249,6 +249,7 @@ static int
 gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
 {
 	int tmp;
+	u32 time32;
 
 	p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
 	if (IS_ERR(p))
@@ -286,9 +287,11 @@ gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
 		p = ERR_PTR(-ENOSYS);
 		goto out_err;
 	}
-	p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
+	p = simple_get_bytes(p, end, &time32, sizeof(time32));
 	if (IS_ERR(p))
 		goto out_err;
+	/* unsigned 32-bit time overflows in year 2106 */
+	ctx->endtime = (time64_t)time32;
 	p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
 	if (IS_ERR(p))
 		goto out_err;
@@ -584,15 +587,18 @@ gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
 		gfp_t gfp_mask)
 {
 	int keylen;
+	u32 time32;
 
 	p = simple_get_bytes(p, end, &ctx->flags, sizeof(ctx->flags));
 	if (IS_ERR(p))
 		goto out_err;
 	ctx->initiate = ctx->flags & KRB5_CTX_FLAG_INITIATOR;
 
-	p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
+	p = simple_get_bytes(p, end, &time32, sizeof(time32));
 	if (IS_ERR(p))
 		goto out_err;
+	/* unsigned 32-bit time overflows in year 2106 */
+	ctx->endtime = (time64_t)time32;
 	p = simple_get_bytes(p, end, &ctx->seq_send64, sizeof(ctx->seq_send64));
 	if (IS_ERR(p))
 		goto out_err;
@@ -655,7 +661,7 @@ gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
 static int
 gss_import_sec_context_kerberos(const void *p, size_t len,
 				struct gss_ctx *ctx_id,
-				time_t *endtime,
+				time64_t *endtime,
 				gfp_t gfp_mask)
 {
 	const void *end = (const void *)((const char *)p + len);

net/sunrpc/auth_gss/gss_krb5_seal.c

@@ -133,14 +133,14 @@ gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text,
 	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
 					    .data = cksumdata};
 	void			*ptr;
-	s32			now;
+	time64_t		now;
 	u32			seq_send;
 	u8			*cksumkey;
 
 	dprintk("RPC:       %s\n", __func__);
 	BUG_ON(ctx == NULL);
 
-	now = get_seconds();
+	now = ktime_get_real_seconds();
 
 	ptr = setup_token(ctx, token);
 
@@ -174,7 +174,7 @@ gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
 	struct xdr_netobj cksumobj = { .len = sizeof(cksumdata),
 				       .data = cksumdata};
 	void *krb5_hdr;
-	s32 now;
+	time64_t now;
 	u64 seq_send;
 	u8 *cksumkey;
 	unsigned int cksum_usage;
@@ -207,7 +207,7 @@ gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
 
 	memcpy(krb5_hdr + GSS_KRB5_TOK_HDR_LEN, cksumobj.data, cksumobj.len);
 
-	now = get_seconds();
+	now = ktime_get_real_seconds();
 
 	return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
 }

net/sunrpc/auth_gss/gss_krb5_unseal.c

@@ -124,7 +124,7 @@ gss_verify_mic_v1(struct krb5_ctx *ctx,
 
 	/* it got through unscathed.  Make sure the context is unexpired */
 
-	now = get_seconds();
+	now = ktime_get_real_seconds();
 
 	if (now > ctx->endtime)
 		return GSS_S_CONTEXT_EXPIRED;
@@ -149,7 +149,7 @@ gss_verify_mic_v2(struct krb5_ctx *ctx,
 	char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
 	struct xdr_netobj cksumobj = {.len = sizeof(cksumdata),
 				      .data = cksumdata};
-	s32 now;
+	time64_t now;
 	u8 *ptr = read_token->data;
 	u8 *cksumkey;
 	u8 flags;
@@ -194,7 +194,7 @@ gss_verify_mic_v2(struct krb5_ctx *ctx,
 		return GSS_S_BAD_SIG;
 
 	/* it got through unscathed.  Make sure the context is unexpired */
-	now = get_seconds();
+	now = ktime_get_real_seconds();
 	if (now > ctx->endtime)
 		return GSS_S_CONTEXT_EXPIRED;
 

net/sunrpc/auth_gss/gss_krb5_wrap.c

@@ -163,7 +163,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
 					    .data = cksumdata};
 	int			blocksize = 0, plainlen;
 	unsigned char		*ptr, *msg_start;
-	s32			now;
+	time64_t		now;
 	int			headlen;
 	struct page		**tmp_pages;
 	u32			seq_send;
@@ -172,7 +172,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
 
 	dprintk("RPC:       %s\n", __func__);
 
-	now = get_seconds();
+	now = ktime_get_real_seconds();
 
 	blocksize = crypto_skcipher_blocksize(kctx->enc);
 	gss_krb5_add_padding(buf, offset, blocksize);
@@ -270,7 +270,7 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
 	char			cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
 	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
 					    .data = cksumdata};
-	s32			now;
+	time64_t		now;
 	int			direction;
 	s32			seqnum;
 	unsigned char		*ptr;
@@ -361,7 +361,7 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
 
 	/* it got through unscathed.  Make sure the context is unexpired */
 
-	now = get_seconds();
+	now = ktime_get_real_seconds();
 
 	if (now > kctx->endtime)
 		return GSS_S_CONTEXT_EXPIRED;
@@ -441,7 +441,7 @@ gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
 		     struct xdr_buf *buf, struct page **pages)
 {
 	u8		*ptr, *plainhdr;
-	s32		now;
+	time64_t	now;
 	u8		flags = 0x00;
 	__be16		*be16ptr;
 	__be64		*be64ptr;
@@ -485,14 +485,14 @@ gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
 	if (err)
 		return err;
 
-	now = get_seconds();
+	now = ktime_get_real_seconds();
 	return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
 }
 
 static u32
 gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
 {
-	s32		now;
+	time64_t	now;
 	u8		*ptr;
 	u8		flags = 0x00;
 	u16		ec, rrc;
@@ -561,7 +561,7 @@ gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
 	/* do sequencing checks */
 
 	/* it got through unscathed.  Make sure the context is unexpired */
-	now = get_seconds();
+	now = ktime_get_real_seconds();
 	if (now > kctx->endtime)
 		return GSS_S_CONTEXT_EXPIRED;
 

net/sunrpc/auth_gss/gss_mech_switch.c

@@ -405,7 +405,7 @@ int
 gss_import_sec_context(const void *input_token, size_t bufsize,
 		       struct gss_api_mech	*mech,
 		       struct gss_ctx		**ctx_id,
-		       time_t			*endtime,
+		       time64_t			*endtime,
 		       gfp_t gfp_mask)
 {
 	if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))

net/sunrpc/auth_gss/svcauth_gss.c

@@ -423,7 +423,7 @@ static int rsc_parse(struct cache_detail *cd,
 	int id;
 	int len, rv;
 	struct rsc rsci, *rscp = NULL;
-	time_t expiry;
+	time64_t expiry;
 	int status = -EINVAL;
 	struct gss_api_mech *gm = NULL;
 
@@ -1177,7 +1177,7 @@ static int gss_proxy_save_rsc(struct cache_detail *cd,
 	static atomic64_t ctxhctr;
 	long long ctxh;
 	struct gss_api_mech *gm = NULL;
-	time_t expiry;
+	time64_t expiry;
 	int status = -EINVAL;
 
 	memset(&rsci, 0, sizeof(rsci));