SUNRPC: Fix error return value of svc_addr_len()

The svc_addr_len() helper function returns -EAFNOSUPPORT if it doesn't
recognize the address family of the passed-in socket address.  However,
the return type of this function is size_t, which means -EAFNOSUPPORT
is turned into a very large positive value in this case.

The check in svc_udp_recvfrom() to see if the return value is less
than zero therefore won't work at all.

Additionally, handle_connect_req() passes this value directly to
memset().  This could cause memset() to clobber a large chunk of memory
if svc_addr_len() has returned an error.  Currently the address family
of these addresses, however, is known to be supported long before
handle_connect_req() is called, so this isn't a real risk.

Change the error return value of svc_addr_len() to zero, which fits in
the range of size_t, and is safer to pass to memset() directly.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Chuck Lever 2009-04-23 19:31:25 -04:00 committed by J. Bruce Fields
parent dcf1a3573e
commit abc5c44d62
2 changed files with 7 additions and 5 deletions

View File

@ -118,7 +118,7 @@ static inline unsigned short svc_addr_port(const struct sockaddr *sa)
return 0;
}
static inline size_t svc_addr_len(struct sockaddr *sa)
static inline size_t svc_addr_len(const struct sockaddr *sa)
{
switch (sa->sa_family) {
case AF_INET:
@ -126,7 +126,8 @@ static inline size_t svc_addr_len(struct sockaddr *sa)
case AF_INET6:
return sizeof(struct sockaddr_in6);
}
return -EAFNOSUPPORT;
return 0;
}
static inline unsigned short svc_xprt_local_port(const struct svc_xprt *xprt)

View File

@ -426,13 +426,14 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
long all[SVC_PKTINFO_SPACE / sizeof(long)];
} buffer;
struct cmsghdr *cmh = &buffer.hdr;
int err, len;
struct msghdr msg = {
.msg_name = svc_addr(rqstp),
.msg_control = cmh,
.msg_controllen = sizeof(buffer),
.msg_flags = MSG_DONTWAIT,
};
size_t len;
int err;
if (test_and_clear_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags))
/* udp sockets need large rcvbuf as all pending
@ -464,8 +465,8 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
return -EAGAIN;
}
len = svc_addr_len(svc_addr(rqstp));
if (len < 0)
return len;
if (len == 0)
return -EAFNOSUPPORT;
rqstp->rq_addrlen = len;
if (skb->tstamp.tv64 == 0) {
skb->tstamp = ktime_get_real();