4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet <edumazet@xxxxxxxxxx> 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 <edumazet@xxxxxxxxxx> Reported-by: Maciej Żenczykowski <maze@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> (cherry picked from commit 3d23401283e80ceb03f765842787e0e79ff598b7) Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ieee802154/6lowpan/reassembly.c | 2 -- net/ipv4/ip_fragment.c | 5 ++--- net/ipv6/netfilter/nf_conntrack_reasm.c | 2 -- net/ipv6/reassembly.c | 4 +--- 4 files changed, 3 insertions(+), 10 deletions(-) --- a/net/ieee802154/6lowpan/reassembly.c +++ b/net/ieee802154/6lowpan/reassembly.c @@ -411,7 +411,6 @@ err: } #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_ .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = proc_doulongvec_minmax, - .extra1 = &zero, .extra2 = &init_net.ieee802154_lowpan.frags.high_thresh }, { --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -672,7 +672,7 @@ struct sk_buff *ip_check_defrag(struct n EXPORT_SYMBOL(ip_check_defrag); #ifdef CONFIG_SYSCTL -static long zero; +static int dist_min; static struct ctl_table ip4_frags_ns_ctl_table[] = { { @@ -689,7 +689,6 @@ static struct ctl_table ip4_frags_ns_ctl .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = proc_doulongvec_minmax, - .extra1 = &zero, .extra2 = &init_net.ipv4.frags.high_thresh }, { @@ -705,7 +704,7 @@ static struct ctl_table ip4_frags_ns_ctl .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, - .extra1 = &zero + .extra1 = &dist_min, }, { } }; --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -63,7 +63,6 @@ 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[] = { { @@ -79,7 +78,6 @@ static struct ctl_table nf_ct_frag6_sysc .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = proc_doulongvec_minmax, - .extra1 = &zero, .extra2 = &init_net.nf_frag.frags.high_thresh }, { --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -554,7 +554,6 @@ static const struct inet6_protocol frag_ }; #ifdef CONFIG_SYSCTL -static int zero; static struct ctl_table ip6_frags_ns_ctl_table[] = { { @@ -570,8 +569,7 @@ static struct ctl_table ip6_frags_ns_ctl .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 }, {