-stable review patch. If anyone has any objections, please let us know.
---------------------
From: Vlad Yasevich <[email protected]>
sctp_getsockopt_local_addrs_old() in net/sctp/socket.c calls
copy_to_user() while the spinlock addr_lock is held. this should not
be done as copy_to_user() might sleep. the call to
sctp_copy_laddrs_to_user() while holding the lock is also problematic
as it calls copy_to_user()
Signed-off-by: Vlad Yasevich <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
net/sctp/socket.c | 96 +++++++++++++++++++++++++++++++++---------------------
1 file changed, 60 insertions(+), 36 deletions(-)
--- linux-2.6.21.1.orig/net/sctp/socket.c
+++ linux-2.6.21.1/net/sctp/socket.c
@@ -3847,7 +3847,7 @@ static int sctp_getsockopt_peer_addrs(st
memcpy(&temp, &from->ipaddr, sizeof(temp));
sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
addrlen = sctp_get_af_specific(sk->sk_family)->sockaddr_len;
- if(space_left < addrlen)
+ if (space_left < addrlen)
return -ENOMEM;
if (copy_to_user(to, &temp, addrlen))
return -EFAULT;
@@ -3936,8 +3936,9 @@ done:
/* Helper function that copies local addresses to user and returns the number
* of addresses copied.
*/
-static int sctp_copy_laddrs_to_user_old(struct sock *sk, __u16 port, int max_addrs,
- void __user *to)
+static int sctp_copy_laddrs_old(struct sock *sk, __u16 port,
+ int max_addrs, void *to,
+ int *bytes_copied)
{
struct list_head *pos, *next;
struct sctp_sockaddr_entry *addr;
@@ -3954,10 +3955,10 @@ static int sctp_copy_laddrs_to_user_old(
sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
&temp);
addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
- if (copy_to_user(to, &temp, addrlen))
- return -EFAULT;
+ memcpy(to, &temp, addrlen);
to += addrlen;
+ *bytes_copied += addrlen;
cnt ++;
if (cnt >= max_addrs) break;
}
@@ -3965,8 +3966,8 @@ static int sctp_copy_laddrs_to_user_old(
return cnt;
}
-static int sctp_copy_laddrs_to_user(struct sock *sk, __u16 port,
- void __user **to, size_t space_left)
+static int sctp_copy_laddrs(struct sock *sk, __u16 port, void *to,
+ size_t space_left, int *bytes_copied)
{
struct list_head *pos, *next;
struct sctp_sockaddr_entry *addr;
@@ -3983,14 +3984,14 @@ static int sctp_copy_laddrs_to_user(stru
sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
&temp);
addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
- if(space_left<addrlen)
+ if (space_left < addrlen)
return -ENOMEM;
- if (copy_to_user(*to, &temp, addrlen))
- return -EFAULT;
+ memcpy(to, &temp, addrlen);
- *to += addrlen;
+ to += addrlen;
cnt ++;
space_left -= addrlen;
+ bytes_copied += addrlen;
}
return cnt;
@@ -4014,6 +4015,8 @@ static int sctp_getsockopt_local_addrs_o
int addrlen;
rwlock_t *addr_lock;
int err = 0;
+ void *addrs;
+ int bytes_copied = 0;
if (len != sizeof(struct sctp_getaddrs_old))
return -EINVAL;
@@ -4041,6 +4044,15 @@ static int sctp_getsockopt_local_addrs_o
to = getaddrs.addrs;
+ /* Allocate space for a local instance of packed array to hold all
+ * the data. We store addresses here first and then put write them
+ * to the user in one shot.
+ */
+ addrs = kmalloc(sizeof(union sctp_addr) * getaddrs.addr_num,
+ GFP_KERNEL);
+ if (!addrs)
+ return -ENOMEM;
+
sctp_read_lock(addr_lock);
/* If the endpoint is bound to 0.0.0.0 or ::0, get the valid
@@ -4050,13 +4062,9 @@ static int sctp_getsockopt_local_addrs_o
addr = list_entry(bp->address_list.next,
struct sctp_sockaddr_entry, list);
if (sctp_is_any(&addr->a)) {
- cnt = sctp_copy_laddrs_to_user_old(sk, bp->port,
- getaddrs.addr_num,
- to);
- if (cnt < 0) {
- err = cnt;
- goto unlock;
- }
+ cnt = sctp_copy_laddrs_old(sk, bp->port,
+ getaddrs.addr_num,
+ addrs, &bytes_copied);
goto copy_getaddrs;
}
}
@@ -4066,22 +4074,29 @@ static int sctp_getsockopt_local_addrs_o
memcpy(&temp, &addr->a, sizeof(temp));
sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
- if (copy_to_user(to, &temp, addrlen)) {
- err = -EFAULT;
- goto unlock;
- }
+ memcpy(addrs, &temp, addrlen);
to += addrlen;
+ bytes_copied += addrlen;
cnt ++;
if (cnt >= getaddrs.addr_num) break;
}
copy_getaddrs:
+ sctp_read_unlock(addr_lock);
+
+ /* copy the entire address list into the user provided space */
+ if (copy_to_user(to, addrs, bytes_copied)) {
+ err = -EFAULT;
+ goto error;
+ }
+
+ /* copy the leading structure back to user */
getaddrs.addr_num = cnt;
if (copy_to_user(optval, &getaddrs, sizeof(struct sctp_getaddrs_old)))
err = -EFAULT;
-unlock:
- sctp_read_unlock(addr_lock);
+error:
+ kfree(addrs);
return err;
}
@@ -4101,7 +4116,8 @@ static int sctp_getsockopt_local_addrs(s
rwlock_t *addr_lock;
int err = 0;
size_t space_left;
- int bytes_copied;
+ int bytes_copied = 0;
+ void *addrs;
if (len <= sizeof(struct sctp_getaddrs))
return -EINVAL;
@@ -4129,6 +4145,9 @@ static int sctp_getsockopt_local_addrs(s
to = optval + offsetof(struct sctp_getaddrs,addrs);
space_left = len - sizeof(struct sctp_getaddrs) -
offsetof(struct sctp_getaddrs,addrs);
+ addrs = kmalloc(space_left, GFP_KERNEL);
+ if (!addrs)
+ return -ENOMEM;
sctp_read_lock(addr_lock);
@@ -4139,11 +4158,11 @@ static int sctp_getsockopt_local_addrs(s
addr = list_entry(bp->address_list.next,
struct sctp_sockaddr_entry, list);
if (sctp_is_any(&addr->a)) {
- cnt = sctp_copy_laddrs_to_user(sk, bp->port,
- &to, space_left);
+ cnt = sctp_copy_laddrs(sk, bp->port, addrs,
+ space_left, &bytes_copied);
if (cnt < 0) {
err = cnt;
- goto unlock;
+ goto error;
}
goto copy_getaddrs;
}
@@ -4154,26 +4173,31 @@ static int sctp_getsockopt_local_addrs(s
memcpy(&temp, &addr->a, sizeof(temp));
sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
- if(space_left < addrlen)
- return -ENOMEM; /*fixme: right error?*/
- if (copy_to_user(to, &temp, addrlen)) {
- err = -EFAULT;
- goto unlock;
+ if (space_left < addrlen) {
+ err = -ENOMEM; /*fixme: right error?*/
+ goto error;
}
+ memcpy(addrs, &temp, addrlen);
to += addrlen;
+ bytes_copied += addrlen;
cnt ++;
space_left -= addrlen;
}
copy_getaddrs:
+ sctp_read_unlock(addr_lock);
+
+ if (copy_to_user(to, addrs, bytes_copied)) {
+ err = -EFAULT;
+ goto error;
+ }
if (put_user(cnt, &((struct sctp_getaddrs __user *)optval)->addr_num))
return -EFAULT;
- bytes_copied = ((char __user *)to) - optval;
if (put_user(bytes_copied, optlen))
return -EFAULT;
-unlock:
- sctp_read_unlock(addr_lock);
+error:
+ kfree(addrs);
return err;
}
--
-
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