inet: frags: fix ip6frag_low_thresh boundary

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: 6e00f7dd5e ("ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2018-04-04 08:35:10 -07:00 committed by David S. Miller
parent 4b2e6877b8
commit 3d23401283
4 changed files with 2 additions and 9 deletions

View File

@ -411,7 +411,6 @@ err:
} }
#ifdef CONFIG_SYSCTL #ifdef CONFIG_SYSCTL
static long zero;
static struct ctl_table lowpan_frags_ns_ctl_table[] = { 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), .maxlen = sizeof(unsigned long),
.mode = 0644, .mode = 0644,
.proc_handler = proc_doulongvec_minmax, .proc_handler = proc_doulongvec_minmax,
.extra1 = &zero,
.extra2 = &init_net.ieee802154_lowpan.frags.high_thresh .extra2 = &init_net.ieee802154_lowpan.frags.high_thresh
}, },
{ {

View File

@ -667,7 +667,7 @@ struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
EXPORT_SYMBOL(ip_check_defrag); EXPORT_SYMBOL(ip_check_defrag);
#ifdef CONFIG_SYSCTL #ifdef CONFIG_SYSCTL
static long zero; static int dist_min;
static struct ctl_table ip4_frags_ns_ctl_table[] = { 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), .maxlen = sizeof(unsigned long),
.mode = 0644, .mode = 0644,
.proc_handler = proc_doulongvec_minmax, .proc_handler = proc_doulongvec_minmax,
.extra1 = &zero,
.extra2 = &init_net.ipv4.frags.high_thresh .extra2 = &init_net.ipv4.frags.high_thresh
}, },
{ {
@ -700,7 +699,7 @@ static struct ctl_table ip4_frags_ns_ctl_table[] = {
.maxlen = sizeof(int), .maxlen = sizeof(int),
.mode = 0644, .mode = 0644,
.proc_handler = proc_dointvec_minmax, .proc_handler = proc_dointvec_minmax,
.extra1 = &zero .extra1 = &dist_min,
}, },
{ } { }
}; };

View File

@ -55,7 +55,6 @@ static const char nf_frags_cache_name[] = "nf-frags";
static struct inet_frags nf_frags; static struct inet_frags nf_frags;
#ifdef CONFIG_SYSCTL #ifdef CONFIG_SYSCTL
static long zero;
static struct ctl_table nf_ct_frag6_sysctl_table[] = { 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), .maxlen = sizeof(unsigned long),
.mode = 0644, .mode = 0644,
.proc_handler = proc_doulongvec_minmax, .proc_handler = proc_doulongvec_minmax,
.extra1 = &zero,
.extra2 = &init_net.nf_frag.frags.high_thresh .extra2 = &init_net.nf_frag.frags.high_thresh
}, },
{ {

View File

@ -548,7 +548,6 @@ static const struct inet6_protocol frag_protocol = {
}; };
#ifdef CONFIG_SYSCTL #ifdef CONFIG_SYSCTL
static int zero;
static struct ctl_table ip6_frags_ns_ctl_table[] = { 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), .maxlen = sizeof(unsigned long),
.mode = 0644, .mode = 0644,
.proc_handler = proc_doulongvec_minmax, .proc_handler = proc_doulongvec_minmax,
.extra1 = &zero,
.extra2 = &init_net.ipv6.frags.high_thresh .extra2 = &init_net.ipv6.frags.high_thresh
}, },
{ {