linux_dsm_epyc7002/include/net/tls.h
Daniel Borkmann f6fadff33e tls: fix NULL pointer dereference on poll
While hacking on kTLS, I ran into the following panic from an
unprivileged netserver / netperf TCP session:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
  PGD 800000037f378067 P4D 800000037f378067 PUD 3c0e61067 PMD 0
  Oops: 0010 [#1] SMP KASAN PTI
  CPU: 1 PID: 2289 Comm: netserver Not tainted 4.17.0+ #139
  Hardware name: LENOVO 20FBCTO1WW/20FBCTO1WW, BIOS N1FET47W (1.21 ) 11/28/2016
  RIP: 0010:          (null)
  Code: Bad RIP value.
  RSP: 0018:ffff88036abcf740 EFLAGS: 00010246
  RAX: dffffc0000000000 RBX: ffff88036f5f6800 RCX: 1ffff1006debed26
  RDX: ffff88036abcf920 RSI: ffff8803cb1a4f00 RDI: ffff8803c258c280
  RBP: ffff8803c258c280 R08: ffff8803c258c280 R09: ffffed006f559d48
  R10: ffff88037aacea43 R11: ffffed006f559d49 R12: ffff8803c258c280
  R13: ffff8803cb1a4f20 R14: 00000000000000db R15: ffffffffc168a350
  FS:  00007f7e631f4700(0000) GS:ffff8803d1c80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffffffffffffffd6 CR3: 00000003ccf64005 CR4: 00000000003606e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   ? tls_sw_poll+0xa4/0x160 [tls]
   ? sock_poll+0x20a/0x680
   ? do_select+0x77b/0x11a0
   ? poll_schedule_timeout.constprop.12+0x130/0x130
   ? pick_link+0xb00/0xb00
   ? read_word_at_a_time+0x13/0x20
   ? vfs_poll+0x270/0x270
   ? deref_stack_reg+0xad/0xe0
   ? __read_once_size_nocheck.constprop.6+0x10/0x10
  [...]

Debugging further, it turns out that calling into ctx->sk_poll() is
invalid since sk_poll itself is NULL which was saved from the original
TCP socket in order for tls_sw_poll() to invoke it.

Looks like the recent conversion from poll to poll_mask callback started
in 1525242310 ("net: add support for ->poll_mask in proto_ops") missed
to eventually convert kTLS, too: TCP's ->poll was converted over to the
->poll_mask in commit 2c7d3daceb ("net/tcp: convert to ->poll_mask")
and therefore kTLS wrongly saved the ->poll old one which is now NULL.

Convert kTLS over to use ->poll_mask instead. Also instead of POLLIN |
POLLRDNORM use the proper EPOLLIN | EPOLLRDNORM bits as the case in
tcp_poll_mask() as well that is mangled here.

Fixes: 2c7d3daceb ("net/tcp: convert to ->poll_mask")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Watson <davejwatson@fb.com>
Tested-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-11 16:29:54 -07:00

401 lines
12 KiB
C

/*
* Copyright (c) 2016-2017, Mellanox Technologies. All rights reserved.
* Copyright (c) 2016-2017, Dave Watson <davejwatson@fb.com>. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef _TLS_OFFLOAD_H
#define _TLS_OFFLOAD_H
#include <linux/types.h>
#include <asm/byteorder.h>
#include <linux/crypto.h>
#include <linux/socket.h>
#include <linux/tcp.h>
#include <net/tcp.h>
#include <net/strparser.h>
#include <uapi/linux/tls.h>
/* Maximum data size carried in a TLS record */
#define TLS_MAX_PAYLOAD_SIZE ((size_t)1 << 14)
#define TLS_HEADER_SIZE 5
#define TLS_NONCE_OFFSET TLS_HEADER_SIZE
#define TLS_CRYPTO_INFO_READY(info) ((info)->cipher_type)
#define TLS_RECORD_TYPE_DATA 0x17
#define TLS_AAD_SPACE_SIZE 13
#define TLS_DEVICE_NAME_MAX 32
/*
* This structure defines the routines for Inline TLS driver.
* The following routines are optional and filled with a
* null pointer if not defined.
*
* @name: Its the name of registered Inline tls device
* @dev_list: Inline tls device list
* int (*feature)(struct tls_device *device);
* Called to return Inline TLS driver capability
*
* int (*hash)(struct tls_device *device, struct sock *sk);
* This function sets Inline driver for listen and program
* device specific functioanlity as required
*
* void (*unhash)(struct tls_device *device, struct sock *sk);
* This function cleans listen state set by Inline TLS driver
*/
struct tls_device {
char name[TLS_DEVICE_NAME_MAX];
struct list_head dev_list;
int (*feature)(struct tls_device *device);
int (*hash)(struct tls_device *device, struct sock *sk);
void (*unhash)(struct tls_device *device, struct sock *sk);
};
struct tls_sw_context_tx {
struct crypto_aead *aead_send;
struct crypto_wait async_wait;
char aad_space[TLS_AAD_SPACE_SIZE];
unsigned int sg_plaintext_size;
int sg_plaintext_num_elem;
struct scatterlist sg_plaintext_data[MAX_SKB_FRAGS];
unsigned int sg_encrypted_size;
int sg_encrypted_num_elem;
struct scatterlist sg_encrypted_data[MAX_SKB_FRAGS];
/* AAD | sg_plaintext_data | sg_tag */
struct scatterlist sg_aead_in[2];
/* AAD | sg_encrypted_data (data contain overhead for hdr&iv&tag) */
struct scatterlist sg_aead_out[2];
};
struct tls_sw_context_rx {
struct crypto_aead *aead_recv;
struct crypto_wait async_wait;
struct strparser strp;
void (*saved_data_ready)(struct sock *sk);
__poll_t (*sk_poll_mask)(struct socket *sock, __poll_t events);
struct sk_buff *recv_pkt;
u8 control;
bool decrypted;
char rx_aad_ciphertext[TLS_AAD_SPACE_SIZE];
char rx_aad_plaintext[TLS_AAD_SPACE_SIZE];
};
struct tls_record_info {
struct list_head list;
u32 end_seq;
int len;
int num_frags;
skb_frag_t frags[MAX_SKB_FRAGS];
};
struct tls_offload_context {
struct crypto_aead *aead_send;
spinlock_t lock; /* protects records list */
struct list_head records_list;
struct tls_record_info *open_record;
struct tls_record_info *retransmit_hint;
u64 hint_record_sn;
u64 unacked_record_sn;
struct scatterlist sg_tx_data[MAX_SKB_FRAGS];
void (*sk_destruct)(struct sock *sk);
u8 driver_state[];
/* The TLS layer reserves room for driver specific state
* Currently the belief is that there is not enough
* driver specific state to justify another layer of indirection
*/
#define TLS_DRIVER_STATE_SIZE (max_t(size_t, 8, sizeof(void *)))
};
#define TLS_OFFLOAD_CONTEXT_SIZE \
(ALIGN(sizeof(struct tls_offload_context), sizeof(void *)) + \
TLS_DRIVER_STATE_SIZE)
enum {
TLS_PENDING_CLOSED_RECORD
};
struct cipher_context {
u16 prepend_size;
u16 tag_size;
u16 overhead_size;
u16 iv_size;
char *iv;
u16 rec_seq_size;
char *rec_seq;
};
struct tls_context {
union {
struct tls_crypto_info crypto_send;
struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
};
union {
struct tls_crypto_info crypto_recv;
struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
};
struct list_head list;
struct net_device *netdev;
refcount_t refcount;
void *priv_ctx_tx;
void *priv_ctx_rx;
u8 tx_conf:3;
u8 rx_conf:3;
struct cipher_context tx;
struct cipher_context rx;
struct scatterlist *partially_sent_record;
u16 partially_sent_offset;
unsigned long flags;
bool in_tcp_sendpages;
u16 pending_open_record_frags;
int (*push_pending_record)(struct sock *sk, int flags);
void (*sk_write_space)(struct sock *sk);
void (*sk_proto_close)(struct sock *sk, long timeout);
int (*setsockopt)(struct sock *sk, int level,
int optname, char __user *optval,
unsigned int optlen);
int (*getsockopt)(struct sock *sk, int level,
int optname, char __user *optval,
int __user *optlen);
int (*hash)(struct sock *sk);
void (*unhash)(struct sock *sk);
};
int wait_on_pending_writer(struct sock *sk, long *timeo);
int tls_sk_query(struct sock *sk, int optname, char __user *optval,
int __user *optlen);
int tls_sk_attach(struct sock *sk, int optname, char __user *optval,
unsigned int optlen);
int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx);
int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
int tls_sw_sendpage(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
void tls_sw_close(struct sock *sk, long timeout);
void tls_sw_free_resources_tx(struct sock *sk);
void tls_sw_free_resources_rx(struct sock *sk);
int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int nonblock, int flags, int *addr_len);
__poll_t tls_sw_poll_mask(struct socket *sock, __poll_t events);
ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
struct pipe_inode_info *pipe,
size_t len, unsigned int flags);
int tls_set_device_offload(struct sock *sk, struct tls_context *ctx);
int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
int tls_device_sendpage(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
void tls_device_sk_destruct(struct sock *sk);
void tls_device_init(void);
void tls_device_cleanup(void);
struct tls_record_info *tls_get_record(struct tls_offload_context *context,
u32 seq, u64 *p_record_sn);
static inline bool tls_record_is_start_marker(struct tls_record_info *rec)
{
return rec->len == 0;
}
static inline u32 tls_record_start_seq(struct tls_record_info *rec)
{
return rec->end_seq - rec->len;
}
void tls_sk_destruct(struct sock *sk, struct tls_context *ctx);
int tls_push_sg(struct sock *sk, struct tls_context *ctx,
struct scatterlist *sg, u16 first_offset,
int flags);
int tls_push_pending_closed_record(struct sock *sk, struct tls_context *ctx,
int flags, long *timeo);
static inline bool tls_is_pending_closed_record(struct tls_context *ctx)
{
return test_bit(TLS_PENDING_CLOSED_RECORD, &ctx->flags);
}
static inline int tls_complete_pending_work(struct sock *sk,
struct tls_context *ctx,
int flags, long *timeo)
{
int rc = 0;
if (unlikely(sk->sk_write_pending))
rc = wait_on_pending_writer(sk, timeo);
if (!rc && tls_is_pending_closed_record(ctx))
rc = tls_push_pending_closed_record(sk, ctx, flags, timeo);
return rc;
}
static inline bool tls_is_partially_sent_record(struct tls_context *ctx)
{
return !!ctx->partially_sent_record;
}
static inline bool tls_is_pending_open_record(struct tls_context *tls_ctx)
{
return tls_ctx->pending_open_record_frags;
}
static inline bool tls_is_sk_tx_device_offloaded(struct sock *sk)
{
return sk_fullsock(sk) &&
/* matches smp_store_release in tls_set_device_offload */
smp_load_acquire(&sk->sk_destruct) == &tls_device_sk_destruct;
}
static inline void tls_err_abort(struct sock *sk, int err)
{
sk->sk_err = err;
sk->sk_error_report(sk);
}
static inline bool tls_bigint_increment(unsigned char *seq, int len)
{
int i;
for (i = len - 1; i >= 0; i--) {
++seq[i];
if (seq[i] != 0)
break;
}
return (i == -1);
}
static inline void tls_advance_record_sn(struct sock *sk,
struct cipher_context *ctx)
{
if (tls_bigint_increment(ctx->rec_seq, ctx->rec_seq_size))
tls_err_abort(sk, EBADMSG);
tls_bigint_increment(ctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
ctx->iv_size);
}
static inline void tls_fill_prepend(struct tls_context *ctx,
char *buf,
size_t plaintext_len,
unsigned char record_type)
{
size_t pkt_len, iv_size = ctx->tx.iv_size;
pkt_len = plaintext_len + iv_size + ctx->tx.tag_size;
/* we cover nonce explicit here as well, so buf should be of
* size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
*/
buf[0] = record_type;
buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
/* we can use IV for nonce explicit according to spec */
buf[3] = pkt_len >> 8;
buf[4] = pkt_len & 0xFF;
memcpy(buf + TLS_NONCE_OFFSET,
ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE, iv_size);
}
static inline void tls_make_aad(char *buf,
size_t size,
char *record_sequence,
int record_sequence_size,
unsigned char record_type)
{
memcpy(buf, record_sequence, record_sequence_size);
buf[8] = record_type;
buf[9] = TLS_1_2_VERSION_MAJOR;
buf[10] = TLS_1_2_VERSION_MINOR;
buf[11] = size >> 8;
buf[12] = size & 0xFF;
}
static inline struct tls_context *tls_get_ctx(const struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
return icsk->icsk_ulp_data;
}
static inline struct tls_sw_context_rx *tls_sw_ctx_rx(
const struct tls_context *tls_ctx)
{
return (struct tls_sw_context_rx *)tls_ctx->priv_ctx_rx;
}
static inline struct tls_sw_context_tx *tls_sw_ctx_tx(
const struct tls_context *tls_ctx)
{
return (struct tls_sw_context_tx *)tls_ctx->priv_ctx_tx;
}
static inline struct tls_offload_context *tls_offload_ctx(
const struct tls_context *tls_ctx)
{
return (struct tls_offload_context *)tls_ctx->priv_ctx_tx;
}
int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
unsigned char *record_type);
void tls_register_device(struct tls_device *device);
void tls_unregister_device(struct tls_device *device);
struct sk_buff *tls_validate_xmit_skb(struct sock *sk,
struct net_device *dev,
struct sk_buff *skb);
int tls_sw_fallback_init(struct sock *sk,
struct tls_offload_context *offload_ctx,
struct tls_crypto_info *crypto_info);
#endif /* _TLS_OFFLOAD_H */