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NFC: Close a race condition in llcp_sock_getname() 

llcp_sock_getname() checks llcp_sock->dev to make sure
llcp_sock is already connected or bound, however, we could
be in the middle of llcp_sock_bind() where llcp_sock->dev
is bound and llcp_sock->service_name_len is set,
but llcp_sock->service_name is not, in this case we would
lead to copy some bytes from a NULL pointer.

Just lock the sock since this is not a hot path anyway.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This commit is contained in:
Cong Wang 2016-01-29 11:37:40 -08:00 committed by Samuel Ortiz
parent 81ca7835f2
commit 03c0535554
1 changed files with 6 additions and 0 deletions
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6
net/nfc/llcp_sock.c
View File

@ -509,6 +509,11 @@ static int llcp_sock_getname(struct socket *sock, struct sockaddr *uaddr,
memset(llcp_addr, 0, sizeof(*llcp_addr));
*len = sizeof(struct sockaddr_nfc_llcp);
lock_sock(sk);
if (!llcp_sock->dev) {
release_sock(sk);
return -EBADFD;
}
llcp_addr->sa_family = AF_NFC;
llcp_addr->dev_idx = llcp_sock->dev->idx;
llcp_addr->target_idx = llcp_sock->target_idx;
@ -518,6 +523,7 @@ static int llcp_sock_getname(struct socket *sock, struct sockaddr *uaddr,
llcp_addr->service_name_len = llcp_sock->service_name_len;
memcpy(llcp_addr->service_name, llcp_sock->service_name,
llcp_addr->service_name_len);
release_sock(sk);
return 0;
}