Use snprintf() in one_sock_name() to prevent overflowing the output
buffer. If the name doesn't fit in the buffer, the buffer is filled
in with an empty string, and -ENAMETOOLONG is returned.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/svcsock.c | 25 ++++++++++++++++++-------
1 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 032b52e..61d4a32 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -240,22 +240,27 @@ out:
/*
* Report socket names for nfsdfs
*/
-static int one_sock_name(char *buf, struct svc_sock *svsk)
+static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining)
{
int len;
switch(svsk->sk_sk->sk_family) {
- case AF_INET:
- len = sprintf(buf, "ipv4 %s %pI4 %d\n",
+ case PF_INET:
+ len = snprintf(buf, remaining, "ipv4 %s %pI4 %d\n",
svsk->sk_sk->sk_protocol == IPPROTO_UDP ?
"udp" : "tcp",
&inet_sk(svsk->sk_sk)->rcv_saddr,
inet_sk(svsk->sk_sk)->num);
break;
default:
- len = sprintf(buf, "*unknown-%d*\n",
+ len = snprintf(buf, remaining, "*unknown-%d*\n",
svsk->sk_sk->sk_family);
}
+
+ if (len >= remaining) {
+ *buf = '\0';
+ return -ENAMETOOLONG;
+ }
return len;
}
@@ -282,15 +287,21 @@ int svc_sock_names(struct svc_serv *serv, char *buf, const size_t buflen,
if (!serv)
return 0;
+
spin_lock_bh(&serv->sv_lock);
list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list) {
- int onelen = one_sock_name(buf+len, svsk);
- if (toclose && strcmp(toclose, buf+len) == 0)
+ int onelen = svc_one_sock_name(svsk, buf + len, buflen - len);
+ if (onelen < 0) {
+ len = onelen;
+ break;
+ }
+ if (toclose && strcmp(toclose, buf + len) == 0)
closesk = svsk;
else
len += onelen;
}
spin_unlock_bh(&serv->sv_lock);
+
if (closesk)
/* Should unregister with portmap, but you cannot
* unregister just one protocol...
@@ -1195,7 +1206,7 @@ int svc_addsock(struct svc_serv *serv, const int fd, char *name_return,
sockfd_put(so);
return err;
}
- return one_sock_name(name_return, svsk);
+ return svc_one_sock_name(svsk, name_return, len);
}
EXPORT_SYMBOL_GPL(svc_addsock);
--
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