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: 6e00f7dd5e4e ("ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh")
Signed-off-by: Eric Dumazet <eduma...@google.com>
Reported-by: Maciej Żenczykowski <m...@google.com>
---
net/ieee802154/6lowpan/reassembly.c | 2 --
net/ipv4/ip_fragment.c | 5 ++---
net/ipv6/netfilter/nf_conntrack_reasm.c | 2 --
net/ipv6/reassembly.c | 2 --
4 files changed, 2 insertions(+), 9 deletions(-)
diff --git a/net/ieee802154/6lowpan/reassembly.c
b/net/ieee802154/6lowpan/reassembly.c
index
44f148a6bb57bb737c35a07e3f070472e209ea23..1790b65944b3ee188608b1a76d4f9a42fb1479d5
100644
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -411,7 +411,6 @@ 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[] = {
{
@@ -428,7 +427,6 @@ 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
},
{
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index
994fa70a910f472ebecc336ddd62d1442014eaba..8e9528ebaa8e1af91172466cc161a83301a217ca
100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -667,7 +667,7 @@ 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[] = {
{
@@ -684,7 +684,6 @@ 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
},
{
@@ -700,7 +699,7 @@ static struct ctl_table ip4_frags_ns_ctl_table[] = {
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
- .extra1 = &zero
+ .extra1 = &dist_min,
},
{ }
};
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c
b/net/ipv6/netfilter/nf_conntrack_reasm.c
index
3622aac343aea3cd0d8165d8681f42595735cd90..5e0332014c1738999e680c1853829f384e880284
100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -55,7 +55,6 @@ static const char nf_frags_cache_name[] = "nf-frags";
static struct inet_frags nf_frags;
#ifdef CONFIG_SYSCTL
-static long zero;
static struct ctl_table nf_ct_frag6_sysctl_table[] = {
{
@@ -71,7 +70,6 @@ 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
},
{
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index
70e4a578b2fb6b2941daeebe4f476214953db047..4979610287e262a873b807a06ac980a17cd1101b
100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -548,7 +548,6 @@ static const struct inet6_protocol frag_protocol = {
};
#ifdef CONFIG_SYSCTL
-static int zero;
static struct ctl_table ip6_frags_ns_ctl_table[] = {
{
@@ -565,7 +564,6 @@ static struct ctl_table ip6_frags_ns_ctl_table[] = {
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_doulongvec_minmax,
- .extra1 = &zero,
.extra2 = &init_net.ipv6.frags.high_thresh
},
{
--
2.17.0.484.g0c8726318c-goog
