Commit 3b350356 authored by Eric Dumazet's avatar Eric Dumazet Committed by Stefan Bader

inet: frags: fix ip6frag_low_thresh boundary

BugLink: https://bugs.launchpad.net/bugs/1818806

commit 3d234012 upstream.

Giving an integer to proc_doulongvec_minmax() is dangerous on 64bit arches,
since linker might place next to it a non zero value preventing a change
to ip6frag_low_thresh.

ip6frag_low_thresh is not used anymore in the kernel, but we do not
want to prematuraly break user scripts wanting to change it.

Since specifying a minimal value of 0 for proc_doulongvec_minmax()
is moot, let's remove these zero values in all defrag units.

Fixes: 6e00f7dd ("ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarMaciej Żenczykowski <maze@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJuerg Haefliger <juergh@canonical.com>
Signed-off-by: default avatarKhalid Elmously <khalid.elmously@canonical.com>
parent 1313c893
......@@ -410,7 +410,6 @@ int lowpan_frag_rcv(struct sk_buff *skb, u8 frag_type)
}
#ifdef CONFIG_SYSCTL
static long zero;
static struct ctl_table lowpan_frags_ns_ctl_table[] = {
{
......@@ -427,7 +426,6 @@ static struct ctl_table lowpan_frags_ns_ctl_table[] = {
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
.extra1 = &zero,
.extra2 = &init_net.ieee802154_lowpan.frags.high_thresh
},
{
......
......@@ -58,14 +58,6 @@
static int sysctl_ipfrag_max_dist __read_mostly = 64;
static const char ip_frag_cache_name[] = "ip4-frags";
struct ipfrag_skb_cb
{
struct inet_skb_parm h;
int offset;
};
#define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb))
/* Describe an entry in the "incomplete datagrams" queue. */
struct ipq {
struct inet_frag_queue q;
......@@ -353,13 +345,13 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
* this fragment, right?
*/
prev = qp->q.fragments_tail;
if (!prev || FRAG_CB(prev)->offset < offset) {
if (!prev || prev->ip_defrag_offset < offset) {
next = NULL;
goto found;
}
prev = NULL;
for (next = qp->q.fragments; next != NULL; next = next->next) {
if (FRAG_CB(next)->offset >= offset)
if (next->ip_defrag_offset >= offset)
break; /* bingo! */
prev = next;
}
......@@ -370,7 +362,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
* any overlaps are eliminated.
*/
if (prev) {
int i = (FRAG_CB(prev)->offset + prev->len) - offset;
int i = (prev->ip_defrag_offset + prev->len) - offset;
if (i > 0) {
offset += i;
......@@ -387,8 +379,8 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
err = -ENOMEM;
while (next && FRAG_CB(next)->offset < end) {
int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */
while (next && next->ip_defrag_offset < end) {
int i = end - next->ip_defrag_offset; /* overlap is 'i' bytes */
if (i < next->len) {
/* Eat head of the next overlapped fragment
......@@ -396,7 +388,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
*/
if (!pskb_pull(next, i))
goto err;
FRAG_CB(next)->offset += i;
next->ip_defrag_offset += i;
qp->q.meat -= i;
if (next->ip_summed != CHECKSUM_UNNECESSARY)
next->ip_summed = CHECKSUM_NONE;
......@@ -420,7 +412,13 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
}
}
FRAG_CB(skb)->offset = offset;
/* Note : skb->ip_defrag_offset and skb->dev share the same location */
dev = skb->dev;
if (dev)
qp->iif = dev->ifindex;
/* Makes sure compiler wont do silly aliasing games */
barrier();
skb->ip_defrag_offset = offset;
/* Insert this fragment in the chain of fragments. */
skb->next = next;
......@@ -431,11 +429,6 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
else
qp->q.fragments = skb;
dev = skb->dev;
if (dev) {
qp->iif = dev->ifindex;
skb->dev = NULL;
}
qp->q.stamp = skb->tstamp;
qp->q.meat += skb->len;
qp->ecn |= ecn;
......@@ -511,7 +504,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
}
WARN_ON(!head);
WARN_ON(FRAG_CB(head)->offset != 0);
WARN_ON(head->ip_defrag_offset != 0);
/* Allocate a new buffer for the datagram. */
ihlen = ip_hdrlen(head);
......@@ -678,7 +671,7 @@ struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
EXPORT_SYMBOL(ip_check_defrag);
#ifdef CONFIG_SYSCTL
static long zero;
static int dist_min;
static struct ctl_table ip4_frags_ns_ctl_table[] = {
{
......@@ -695,7 +688,6 @@ static struct ctl_table ip4_frags_ns_ctl_table[] = {
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
.extra1 = &zero,
.extra2 = &init_net.ipv4.frags.high_thresh
},
{
......@@ -724,7 +716,7 @@ static struct ctl_table ip4_frags_ctl_table[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &zero
.extra1 = &dist_min,
},
{ }
};
......
......@@ -64,7 +64,6 @@ struct nf_ct_frag6_skb_cb
static struct inet_frags nf_frags;
#ifdef CONFIG_SYSCTL
static long zero;
static struct ctl_table nf_ct_frag6_sysctl_table[] = {
{
......@@ -80,7 +79,6 @@ static struct ctl_table nf_ct_frag6_sysctl_table[] = {
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
.extra1 = &zero,
.extra2 = &init_net.nf_frag.frags.high_thresh
},
{
......
......@@ -547,7 +547,6 @@ static const struct inet6_protocol frag_protocol = {
};
#ifdef CONFIG_SYSCTL
static int zero;
static struct ctl_table ip6_frags_ns_ctl_table[] = {
{
......@@ -563,8 +562,7 @@ static struct ctl_table ip6_frags_ns_ctl_table[] = {
.data = &init_net.ipv6.frags.low_thresh,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &zero,
.proc_handler = proc_doulongvec_minmax,
.extra2 = &init_net.ipv6.frags.high_thresh
},
{
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment