| Message ID | 20180404153510.213392-1-edumazet@google.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | None | expand |
On 04/04/2018 08:35 AM, Eric Dumazet wrote: > 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@google.com> > Reported-by: Maciej Żenczykowski <maze@google.com> David, please ignore the net-next 2/2 in the title, there is a single patch, targeting net tree, sorry for the confusion.
From: Eric Dumazet <edumazet@google.com> Date: Wed, 4 Apr 2018 08:35:10 -0700 > 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@google.com> > Reported-by: Maciej Żenczykowski <maze@google.com> Applied, thanks Eric.
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 }, {
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@google.com> Reported-by: Maciej Żenczykowski <maze@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(-)