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authorDavid S. Miller <davem@davemloft.net>2014-11-10 14:25:49 -0500
committerDavid S. Miller <davem@davemloft.net>2014-11-10 14:25:49 -0500
commite344458fc011bf4bea52a090895c38c4634ab402 (patch)
treedb116a813dd808850455b36ba1c5e34b523a251e /net
parent1ef8019be8799c39f316a772ffdd705c46029752 (diff)
parentc008ba5bdc9fa830e1a349b20b0be5a137bdef7a (diff)
Merge branch 'raw_probe_proto_opt'
Herbert Xu says: ==================== ipv4: Simplify raw_probe_proto_opt and avoid reading user iov twice This series rewrites the function raw_probe_proto_opt in a more readable fasion, and then fixes the long-standing bug where we read the probed bytes twice which means that what we're using to probe may in fact be invalid. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/raw.c104
1 files changed, 61 insertions, 43 deletions
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index ee8fa4bf3b73..43385a9fa441 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -79,6 +79,16 @@
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/compat.h>
+#include <linux/uio.h>
+
+struct raw_frag_vec {
+ struct iovec *iov;
+ union {
+ struct icmphdr icmph;
+ char c[1];
+ } hdr;
+ int hlen;
+};
static struct raw_hashinfo raw_v4_hashinfo = {
.lock = __RW_LOCK_UNLOCKED(raw_v4_hashinfo.lock),
@@ -420,53 +430,57 @@ error:
return err;
}
-static int raw_probe_proto_opt(struct flowi4 *fl4, struct msghdr *msg)
+static int raw_probe_proto_opt(struct raw_frag_vec *rfv, struct flowi4 *fl4)
{
- struct iovec *iov;
- u8 __user *type = NULL;
- u8 __user *code = NULL;
- int probed = 0;
- unsigned int i;
+ int err;
- if (!msg->msg_iov)
+ if (fl4->flowi4_proto != IPPROTO_ICMP)
return 0;
- for (i = 0; i < msg->msg_iovlen; i++) {
- iov = &msg->msg_iov[i];
- if (!iov)
- continue;
-
- switch (fl4->flowi4_proto) {
- case IPPROTO_ICMP:
- /* check if one-byte field is readable or not. */
- if (iov->iov_base && iov->iov_len < 1)
- break;
-
- if (!type) {
- type = iov->iov_base;
- /* check if code field is readable or not. */
- if (iov->iov_len > 1)
- code = type + 1;
- } else if (!code)
- code = iov->iov_base;
-
- if (type && code) {
- if (get_user(fl4->fl4_icmp_type, type) ||
- get_user(fl4->fl4_icmp_code, code))
- return -EFAULT;
- probed = 1;
- }
- break;
- default:
- probed = 1;
- break;
- }
- if (probed)
- break;
- }
+ /* We only need the first two bytes. */
+ rfv->hlen = 2;
+
+ err = memcpy_fromiovec(rfv->hdr.c, rfv->iov, rfv->hlen);
+ if (err)
+ return err;
+
+ fl4->fl4_icmp_type = rfv->hdr.icmph.type;
+ fl4->fl4_icmp_code = rfv->hdr.icmph.code;
+
return 0;
}
+static int raw_getfrag(void *from, char *to, int offset, int len, int odd,
+ struct sk_buff *skb)
+{
+ struct raw_frag_vec *rfv = from;
+
+ if (offset < rfv->hlen) {
+ int copy = min(rfv->hlen - offset, len);
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL)
+ memcpy(to, rfv->hdr.c + offset, copy);
+ else
+ skb->csum = csum_block_add(
+ skb->csum,
+ csum_partial_copy_nocheck(rfv->hdr.c + offset,
+ to, copy, 0),
+ odd);
+
+ odd = 0;
+ offset += copy;
+ to += copy;
+ len -= copy;
+
+ if (!len)
+ return 0;
+ }
+
+ offset -= rfv->hlen;
+
+ return ip_generic_getfrag(rfv->iov, to, offset, len, odd, skb);
+}
+
static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
size_t len)
{
@@ -480,6 +494,7 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
u8 tos;
int err;
struct ip_options_data opt_copy;
+ struct raw_frag_vec rfv;
err = -EMSGSIZE;
if (len > 0xFFFF)
@@ -585,7 +600,10 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
daddr, saddr, 0, 0);
if (!inet->hdrincl) {
- err = raw_probe_proto_opt(&fl4, msg);
+ rfv.iov = msg->msg_iov;
+ rfv.hlen = 0;
+
+ err = raw_probe_proto_opt(&rfv, &fl4);
if (err)
goto done;
}
@@ -616,8 +634,8 @@ back_from_confirm:
if (!ipc.addr)
ipc.addr = fl4.daddr;
lock_sock(sk);
- err = ip_append_data(sk, &fl4, ip_generic_getfrag,
- msg->msg_iov, len, 0,
+ err = ip_append_data(sk, &fl4, raw_getfrag,
+ &rfv, len, 0,
&ipc, &rt, msg->msg_flags);
if (err)
ip_flush_pending_frames(sk);

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