linux_dsm_epyc7002/net/nfc/llcp_commands.c
Tetsuo Handa 3bc53be9db net/nfc: Avoid stalls when nfc_alloc_send_skb() returned NULL.
syzbot is reporting stalls at nfc_llcp_send_ui_frame() [1]. This is
because nfc_llcp_send_ui_frame() is retrying the loop without any delay
when nonblocking nfc_alloc_send_skb() returned NULL.

Since there is no need to use MSG_DONTWAIT if we retry until
sock_alloc_send_pskb() succeeds, let's use blocking call.
Also, in case an unexpected error occurred, let's break the loop
if blocking nfc_alloc_send_skb() failed.

[1] https://syzkaller.appspot.com/bug?id=4a131cc571c3733e0eff6bc673f4e36ae48f19c6

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+d29d18215e477cfbfbdd@syzkaller.appspotmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-18 10:51:45 -07:00

805 lines
16 KiB
C

/*
* Copyright (C) 2011 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#define pr_fmt(fmt) "llcp: %s: " fmt, __func__
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/nfc.h>
#include <net/nfc/nfc.h>
#include "nfc.h"
#include "llcp.h"
static u8 llcp_tlv_length[LLCP_TLV_MAX] = {
0,
1, /* VERSION */
2, /* MIUX */
2, /* WKS */
1, /* LTO */
1, /* RW */
0, /* SN */
1, /* OPT */
0, /* SDREQ */
2, /* SDRES */
};
static u8 llcp_tlv8(u8 *tlv, u8 type)
{
if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
return 0;
return tlv[2];
}
static u16 llcp_tlv16(u8 *tlv, u8 type)
{
if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
return 0;
return be16_to_cpu(*((__be16 *)(tlv + 2)));
}
static u8 llcp_tlv_version(u8 *tlv)
{
return llcp_tlv8(tlv, LLCP_TLV_VERSION);
}
static u16 llcp_tlv_miux(u8 *tlv)
{
return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
}
static u16 llcp_tlv_wks(u8 *tlv)
{
return llcp_tlv16(tlv, LLCP_TLV_WKS);
}
static u16 llcp_tlv_lto(u8 *tlv)
{
return llcp_tlv8(tlv, LLCP_TLV_LTO);
}
static u8 llcp_tlv_opt(u8 *tlv)
{
return llcp_tlv8(tlv, LLCP_TLV_OPT);
}
static u8 llcp_tlv_rw(u8 *tlv)
{
return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
}
u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length)
{
u8 *tlv, length;
pr_debug("type %d\n", type);
if (type >= LLCP_TLV_MAX)
return NULL;
length = llcp_tlv_length[type];
if (length == 0 && value_length == 0)
return NULL;
else if (length == 0)
length = value_length;
*tlv_length = 2 + length;
tlv = kzalloc(2 + length, GFP_KERNEL);
if (tlv == NULL)
return tlv;
tlv[0] = type;
tlv[1] = length;
memcpy(tlv + 2, value, length);
return tlv;
}
struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap)
{
struct nfc_llcp_sdp_tlv *sdres;
u8 value[2];
sdres = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
if (sdres == NULL)
return NULL;
value[0] = tid;
value[1] = sap;
sdres->tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2,
&sdres->tlv_len);
if (sdres->tlv == NULL) {
kfree(sdres);
return NULL;
}
sdres->tid = tid;
sdres->sap = sap;
INIT_HLIST_NODE(&sdres->node);
return sdres;
}
struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, char *uri,
size_t uri_len)
{
struct nfc_llcp_sdp_tlv *sdreq;
pr_debug("uri: %s, len: %zu\n", uri, uri_len);
/* sdreq->tlv_len is u8, takes uri_len, + 3 for header, + 1 for NULL */
if (WARN_ON_ONCE(uri_len > U8_MAX - 4))
return NULL;
sdreq = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
if (sdreq == NULL)
return NULL;
sdreq->tlv_len = uri_len + 3;
if (uri[uri_len - 1] == 0)
sdreq->tlv_len--;
sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL);
if (sdreq->tlv == NULL) {
kfree(sdreq);
return NULL;
}
sdreq->tlv[0] = LLCP_TLV_SDREQ;
sdreq->tlv[1] = sdreq->tlv_len - 2;
sdreq->tlv[2] = tid;
sdreq->tid = tid;
sdreq->uri = sdreq->tlv + 3;
memcpy(sdreq->uri, uri, uri_len);
sdreq->time = jiffies;
INIT_HLIST_NODE(&sdreq->node);
return sdreq;
}
void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
{
kfree(sdp->tlv);
kfree(sdp);
}
void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head)
{
struct nfc_llcp_sdp_tlv *sdp;
struct hlist_node *n;
hlist_for_each_entry_safe(sdp, n, head, node) {
hlist_del(&sdp->node);
nfc_llcp_free_sdp_tlv(sdp);
}
}
int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
u8 *tlv_array, u16 tlv_array_len)
{
u8 *tlv = tlv_array, type, length, offset = 0;
pr_debug("TLV array length %d\n", tlv_array_len);
if (local == NULL)
return -ENODEV;
while (offset < tlv_array_len) {
type = tlv[0];
length = tlv[1];
pr_debug("type 0x%x length %d\n", type, length);
switch (type) {
case LLCP_TLV_VERSION:
local->remote_version = llcp_tlv_version(tlv);
break;
case LLCP_TLV_MIUX:
local->remote_miu = llcp_tlv_miux(tlv) + 128;
break;
case LLCP_TLV_WKS:
local->remote_wks = llcp_tlv_wks(tlv);
break;
case LLCP_TLV_LTO:
local->remote_lto = llcp_tlv_lto(tlv) * 10;
break;
case LLCP_TLV_OPT:
local->remote_opt = llcp_tlv_opt(tlv);
break;
default:
pr_err("Invalid gt tlv value 0x%x\n", type);
break;
}
offset += length + 2;
tlv += length + 2;
}
pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n",
local->remote_version, local->remote_miu,
local->remote_lto, local->remote_opt,
local->remote_wks);
return 0;
}
int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
u8 *tlv_array, u16 tlv_array_len)
{
u8 *tlv = tlv_array, type, length, offset = 0;
pr_debug("TLV array length %d\n", tlv_array_len);
if (sock == NULL)
return -ENOTCONN;
while (offset < tlv_array_len) {
type = tlv[0];
length = tlv[1];
pr_debug("type 0x%x length %d\n", type, length);
switch (type) {
case LLCP_TLV_MIUX:
sock->remote_miu = llcp_tlv_miux(tlv) + 128;
break;
case LLCP_TLV_RW:
sock->remote_rw = llcp_tlv_rw(tlv);
break;
case LLCP_TLV_SN:
break;
default:
pr_err("Invalid gt tlv value 0x%x\n", type);
break;
}
offset += length + 2;
tlv += length + 2;
}
pr_debug("sock %p rw %d miu %d\n", sock,
sock->remote_rw, sock->remote_miu);
return 0;
}
static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
u8 dsap, u8 ssap, u8 ptype)
{
u8 header[2];
pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
header[0] = (u8)((dsap << 2) | (ptype >> 2));
header[1] = (u8)((ptype << 6) | ssap);
pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
skb_put_data(pdu, header, LLCP_HEADER_SIZE);
return pdu;
}
static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv,
u8 tlv_length)
{
/* XXX Add an skb length check */
if (tlv == NULL)
return NULL;
skb_put_data(pdu, tlv, tlv_length);
return pdu;
}
static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock,
u8 cmd, u16 size)
{
struct sk_buff *skb;
int err;
if (sock->ssap == 0)
return NULL;
skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
size + LLCP_HEADER_SIZE, &err);
if (skb == NULL) {
pr_err("Could not allocate PDU\n");
return NULL;
}
skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
return skb;
}
int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
{
struct sk_buff *skb;
struct nfc_dev *dev;
struct nfc_llcp_local *local;
pr_debug("Sending DISC\n");
local = sock->local;
if (local == NULL)
return -ENODEV;
dev = sock->dev;
if (dev == NULL)
return -ENODEV;
skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
if (skb == NULL)
return -ENOMEM;
skb_queue_tail(&local->tx_queue, skb);
return 0;
}
int nfc_llcp_send_symm(struct nfc_dev *dev)
{
struct sk_buff *skb;
struct nfc_llcp_local *local;
u16 size = 0;
pr_debug("Sending SYMM\n");
local = nfc_llcp_find_local(dev);
if (local == NULL)
return -ENODEV;
size += LLCP_HEADER_SIZE;
size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
skb = alloc_skb(size, GFP_KERNEL);
if (skb == NULL)
return -ENOMEM;
skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
__net_timestamp(skb);
nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX);
return nfc_data_exchange(dev, local->target_idx, skb,
nfc_llcp_recv, local);
}
int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
{
struct nfc_llcp_local *local;
struct sk_buff *skb;
u8 *service_name_tlv = NULL, service_name_tlv_length;
u8 *miux_tlv = NULL, miux_tlv_length;
u8 *rw_tlv = NULL, rw_tlv_length, rw;
int err;
u16 size = 0;
__be16 miux;
pr_debug("Sending CONNECT\n");
local = sock->local;
if (local == NULL)
return -ENODEV;
if (sock->service_name != NULL) {
service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
sock->service_name,
sock->service_name_len,
&service_name_tlv_length);
size += service_name_tlv_length;
}
/* If the socket parameters are not set, use the local ones */
miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
local->miux : sock->miux;
rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
&miux_tlv_length);
size += miux_tlv_length;
rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
size += rw_tlv_length;
pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
if (skb == NULL) {
err = -ENOMEM;
goto error_tlv;
}
llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length);
llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
skb_queue_tail(&local->tx_queue, skb);
err = 0;
error_tlv:
if (err)
pr_err("error %d\n", err);
kfree(service_name_tlv);
kfree(miux_tlv);
kfree(rw_tlv);
return err;
}
int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
{
struct nfc_llcp_local *local;
struct sk_buff *skb;
u8 *miux_tlv = NULL, miux_tlv_length;
u8 *rw_tlv = NULL, rw_tlv_length, rw;
int err;
u16 size = 0;
__be16 miux;
pr_debug("Sending CC\n");
local = sock->local;
if (local == NULL)
return -ENODEV;
/* If the socket parameters are not set, use the local ones */
miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
local->miux : sock->miux;
rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
&miux_tlv_length);
size += miux_tlv_length;
rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
size += rw_tlv_length;
skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
if (skb == NULL) {
err = -ENOMEM;
goto error_tlv;
}
llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
skb_queue_tail(&local->tx_queue, skb);
err = 0;
error_tlv:
if (err)
pr_err("error %d\n", err);
kfree(miux_tlv);
kfree(rw_tlv);
return err;
}
static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
size_t tlv_length)
{
struct sk_buff *skb;
struct nfc_dev *dev;
u16 size = 0;
if (local == NULL)
return ERR_PTR(-ENODEV);
dev = local->dev;
if (dev == NULL)
return ERR_PTR(-ENODEV);
size += LLCP_HEADER_SIZE;
size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
size += tlv_length;
skb = alloc_skb(size, GFP_KERNEL);
if (skb == NULL)
return ERR_PTR(-ENOMEM);
skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
return skb;
}
int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
struct hlist_head *tlv_list, size_t tlvs_len)
{
struct nfc_llcp_sdp_tlv *sdp;
struct hlist_node *n;
struct sk_buff *skb;
skb = nfc_llcp_allocate_snl(local, tlvs_len);
if (IS_ERR(skb))
return PTR_ERR(skb);
hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
skb_put_data(skb, sdp->tlv, sdp->tlv_len);
hlist_del(&sdp->node);
nfc_llcp_free_sdp_tlv(sdp);
}
skb_queue_tail(&local->tx_queue, skb);
return 0;
}
int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
struct hlist_head *tlv_list, size_t tlvs_len)
{
struct nfc_llcp_sdp_tlv *sdreq;
struct hlist_node *n;
struct sk_buff *skb;
skb = nfc_llcp_allocate_snl(local, tlvs_len);
if (IS_ERR(skb))
return PTR_ERR(skb);
mutex_lock(&local->sdreq_lock);
if (hlist_empty(&local->pending_sdreqs))
mod_timer(&local->sdreq_timer,
jiffies + msecs_to_jiffies(3 * local->remote_lto));
hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
skb_put_data(skb, sdreq->tlv, sdreq->tlv_len);
hlist_del(&sdreq->node);
hlist_add_head(&sdreq->node, &local->pending_sdreqs);
}
mutex_unlock(&local->sdreq_lock);
skb_queue_tail(&local->tx_queue, skb);
return 0;
}
int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
{
struct sk_buff *skb;
struct nfc_dev *dev;
u16 size = 1; /* Reason code */
pr_debug("Sending DM reason 0x%x\n", reason);
if (local == NULL)
return -ENODEV;
dev = local->dev;
if (dev == NULL)
return -ENODEV;
size += LLCP_HEADER_SIZE;
size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
skb = alloc_skb(size, GFP_KERNEL);
if (skb == NULL)
return -ENOMEM;
skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
skb_put_data(skb, &reason, 1);
skb_queue_head(&local->tx_queue, skb);
return 0;
}
int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
struct msghdr *msg, size_t len)
{
struct sk_buff *pdu;
struct sock *sk = &sock->sk;
struct nfc_llcp_local *local;
size_t frag_len = 0, remaining_len;
u8 *msg_data, *msg_ptr;
u16 remote_miu;
pr_debug("Send I frame len %zd\n", len);
local = sock->local;
if (local == NULL)
return -ENODEV;
/* Remote is ready but has not acknowledged our frames */
if((sock->remote_ready &&
skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw &&
skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
pr_err("Pending queue is full %d frames\n",
skb_queue_len(&sock->tx_pending_queue));
return -ENOBUFS;
}
/* Remote is not ready and we've been queueing enough frames */
if ((!sock->remote_ready &&
skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
pr_err("Tx queue is full %d frames\n",
skb_queue_len(&sock->tx_queue));
return -ENOBUFS;
}
msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
if (msg_data == NULL)
return -ENOMEM;
if (memcpy_from_msg(msg_data, msg, len)) {
kfree(msg_data);
return -EFAULT;
}
remaining_len = len;
msg_ptr = msg_data;
do {
remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
LLCP_DEFAULT_MIU : sock->remote_miu;
frag_len = min_t(size_t, remote_miu, remaining_len);
pr_debug("Fragment %zd bytes remaining %zd",
frag_len, remaining_len);
pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
frag_len + LLCP_SEQUENCE_SIZE);
if (pdu == NULL) {
kfree(msg_data);
return -ENOMEM;
}
skb_put(pdu, LLCP_SEQUENCE_SIZE);
if (likely(frag_len > 0))
skb_put_data(pdu, msg_ptr, frag_len);
skb_queue_tail(&sock->tx_queue, pdu);
lock_sock(sk);
nfc_llcp_queue_i_frames(sock);
release_sock(sk);
remaining_len -= frag_len;
msg_ptr += frag_len;
} while (remaining_len > 0);
kfree(msg_data);
return len;
}
int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
struct msghdr *msg, size_t len)
{
struct sk_buff *pdu;
struct nfc_llcp_local *local;
size_t frag_len = 0, remaining_len;
u8 *msg_ptr, *msg_data;
u16 remote_miu;
int err;
pr_debug("Send UI frame len %zd\n", len);
local = sock->local;
if (local == NULL)
return -ENODEV;
msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
if (msg_data == NULL)
return -ENOMEM;
if (memcpy_from_msg(msg_data, msg, len)) {
kfree(msg_data);
return -EFAULT;
}
remaining_len = len;
msg_ptr = msg_data;
do {
remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
local->remote_miu : sock->remote_miu;
frag_len = min_t(size_t, remote_miu, remaining_len);
pr_debug("Fragment %zd bytes remaining %zd",
frag_len, remaining_len);
pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0,
frag_len + LLCP_HEADER_SIZE, &err);
if (pdu == NULL) {
pr_err("Could not allocate PDU (error=%d)\n", err);
len -= remaining_len;
if (len == 0)
len = err;
break;
}
pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
if (likely(frag_len > 0))
skb_put_data(pdu, msg_ptr, frag_len);
/* No need to check for the peer RW for UI frames */
skb_queue_tail(&local->tx_queue, pdu);
remaining_len -= frag_len;
msg_ptr += frag_len;
} while (remaining_len > 0);
kfree(msg_data);
return len;
}
int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
{
struct sk_buff *skb;
struct nfc_llcp_local *local;
pr_debug("Send rr nr %d\n", sock->recv_n);
local = sock->local;
if (local == NULL)
return -ENODEV;
skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
if (skb == NULL)
return -ENOMEM;
skb_put(skb, LLCP_SEQUENCE_SIZE);
skb->data[2] = sock->recv_n;
skb_queue_head(&local->tx_queue, skb);
return 0;
}