nfc: Add KCOV annotations

Add remote KCOV annotations for NFC processing that is done
in background threads. This enables efficient coverage-guided
fuzzing of the NFC subsystem.

The intention is to add annotations to background threads that
process skb's that were allocated in syscall context
(thus have a KCOV handle associated with the current fuzz test).
This includes nci_recv_frame() that is called by the virtual nci
driver in the syscall context.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Bongsu Jeon <bongsu.jeon@samsung.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dmitry Vyukov 2022-10-30 16:03:37 +01:00 committed by David S. Miller
parent 82fd151d38
commit 7e8cdc9714
3 changed files with 13 additions and 2 deletions

View File

@ -24,6 +24,7 @@
#include <linux/sched.h>
#include <linux/bitops.h>
#include <linux/skbuff.h>
#include <linux/kcov.h>
#include "../nfc.h"
#include <net/nfc/nci.h>
@ -1472,6 +1473,7 @@ static void nci_tx_work(struct work_struct *work)
skb = skb_dequeue(&ndev->tx_q);
if (!skb)
return;
kcov_remote_start_common(skb_get_kcov_handle(skb));
/* Check if data flow control is used */
if (atomic_read(&conn_info->credits_cnt) !=
@ -1487,6 +1489,7 @@ static void nci_tx_work(struct work_struct *work)
mod_timer(&ndev->data_timer,
jiffies + msecs_to_jiffies(NCI_DATA_TIMEOUT));
kcov_remote_stop();
}
}
@ -1497,7 +1500,8 @@ static void nci_rx_work(struct work_struct *work)
struct nci_dev *ndev = container_of(work, struct nci_dev, rx_work);
struct sk_buff *skb;
while ((skb = skb_dequeue(&ndev->rx_q))) {
for (; (skb = skb_dequeue(&ndev->rx_q)); kcov_remote_stop()) {
kcov_remote_start_common(skb_get_kcov_handle(skb));
/* Send copy to sniffer */
nfc_send_to_raw_sock(ndev->nfc_dev, skb,
@ -1551,6 +1555,7 @@ static void nci_cmd_work(struct work_struct *work)
if (!skb)
return;
kcov_remote_start_common(skb_get_kcov_handle(skb));
atomic_dec(&ndev->cmd_cnt);
pr_debug("NCI TX: MT=cmd, PBF=%d, GID=0x%x, OID=0x%x, plen=%d\n",
@ -1563,6 +1568,7 @@ static void nci_cmd_work(struct work_struct *work)
mod_timer(&ndev->cmd_timer,
jiffies + msecs_to_jiffies(NCI_CMD_TIMEOUT));
kcov_remote_stop();
}
}

View File

@ -14,6 +14,7 @@
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>
#include <linux/nfc.h>
#include <linux/kcov.h>
struct nci_data {
u8 conn_id;
@ -409,7 +410,8 @@ static void nci_hci_msg_rx_work(struct work_struct *work)
const struct nci_hcp_message *message;
u8 pipe, type, instruction;
while ((skb = skb_dequeue(&hdev->msg_rx_queue)) != NULL) {
for (; (skb = skb_dequeue(&hdev->msg_rx_queue)); kcov_remote_stop()) {
kcov_remote_start_common(skb_get_kcov_handle(skb));
pipe = NCI_HCP_MSG_GET_PIPE(skb->data[0]);
skb_pull(skb, NCI_HCI_HCP_PACKET_HEADER_LEN);
message = (struct nci_hcp_message *)skb->data;

View File

@ -12,6 +12,7 @@
#include <net/tcp_states.h>
#include <linux/nfc.h>
#include <linux/export.h>
#include <linux/kcov.h>
#include "nfc.h"
@ -189,6 +190,7 @@ static void rawsock_tx_work(struct work_struct *work)
}
skb = skb_dequeue(&sk->sk_write_queue);
kcov_remote_start_common(skb_get_kcov_handle(skb));
sock_hold(sk);
rc = nfc_data_exchange(dev, target_idx, skb,
@ -197,6 +199,7 @@ static void rawsock_tx_work(struct work_struct *work)
rawsock_report_error(sk, rc);
sock_put(sk);
}
kcov_remote_stop();
}
static int rawsock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)