Commit 52d1aa8b authored by Daniel Xu's avatar Daniel Xu Committed by Pablo Neira Ayuso

netfilter: conntrack: Fix data-races around ct mark

nf_conn:mark can be read from and written to in parallel. Use
READ_ONCE()/WRITE_ONCE() for reads and writes to prevent unwanted
compiler optimizations.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarDaniel Xu <dxu@dxuuu.xyz>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 40b9d1ab
......@@ -296,7 +296,7 @@ skb_flow_dissect_ct(const struct sk_buff *skb,
key->ct_zone = ct->zone.id;
#endif
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
key->ct_mark = ct->mark;
key->ct_mark = READ_ONCE(ct->mark);
#endif
cl = nf_ct_labels_find(ct);
......
......@@ -435,7 +435,7 @@ clusterip_tg(struct sk_buff *skb, const struct xt_action_param *par)
switch (ctinfo) {
case IP_CT_NEW:
ct->mark = hash;
WRITE_ONCE(ct->mark, hash);
break;
case IP_CT_RELATED:
case IP_CT_RELATED_REPLY:
......@@ -452,7 +452,7 @@ clusterip_tg(struct sk_buff *skb, const struct xt_action_param *par)
#ifdef DEBUG
nf_ct_dump_tuple_ip(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
#endif
pr_debug("hash=%u ct_hash=%u ", hash, ct->mark);
pr_debug("hash=%u ct_hash=%u ", hash, READ_ONCE(ct->mark));
if (!clusterip_responsible(cipinfo->config, hash)) {
pr_debug("not responsible\n");
return NF_DROP;
......
......@@ -1781,7 +1781,7 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
}
#ifdef CONFIG_NF_CONNTRACK_MARK
ct->mark = exp->master->mark;
ct->mark = READ_ONCE(exp->master->mark);
#endif
#ifdef CONFIG_NF_CONNTRACK_SECMARK
ct->secmark = exp->master->secmark;
......
......@@ -328,9 +328,9 @@ ctnetlink_dump_timestamp(struct sk_buff *skb, const struct nf_conn *ct)
}
#ifdef CONFIG_NF_CONNTRACK_MARK
static int ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)
static int ctnetlink_dump_mark(struct sk_buff *skb, u32 mark)
{
if (nla_put_be32(skb, CTA_MARK, htonl(ct->mark)))
if (nla_put_be32(skb, CTA_MARK, htonl(mark)))
goto nla_put_failure;
return 0;
......@@ -543,7 +543,7 @@ static int ctnetlink_dump_extinfo(struct sk_buff *skb,
static int ctnetlink_dump_info(struct sk_buff *skb, struct nf_conn *ct)
{
if (ctnetlink_dump_status(skb, ct) < 0 ||
ctnetlink_dump_mark(skb, ct) < 0 ||
ctnetlink_dump_mark(skb, READ_ONCE(ct->mark)) < 0 ||
ctnetlink_dump_secctx(skb, ct) < 0 ||
ctnetlink_dump_id(skb, ct) < 0 ||
ctnetlink_dump_use(skb, ct) < 0 ||
......@@ -722,6 +722,7 @@ ctnetlink_conntrack_event(unsigned int events, const struct nf_ct_event *item)
struct sk_buff *skb;
unsigned int type;
unsigned int flags = 0, group;
u32 mark;
int err;
if (events & (1 << IPCT_DESTROY)) {
......@@ -826,8 +827,9 @@ ctnetlink_conntrack_event(unsigned int events, const struct nf_ct_event *item)
}
#ifdef CONFIG_NF_CONNTRACK_MARK
if ((events & (1 << IPCT_MARK) || ct->mark)
&& ctnetlink_dump_mark(skb, ct) < 0)
mark = READ_ONCE(ct->mark);
if ((events & (1 << IPCT_MARK) || mark) &&
ctnetlink_dump_mark(skb, mark) < 0)
goto nla_put_failure;
#endif
nlmsg_end(skb, nlh);
......@@ -1154,7 +1156,7 @@ static int ctnetlink_filter_match(struct nf_conn *ct, void *data)
}
#ifdef CONFIG_NF_CONNTRACK_MARK
if ((ct->mark & filter->mark.mask) != filter->mark.val)
if ((READ_ONCE(ct->mark) & filter->mark.mask) != filter->mark.val)
goto ignore_entry;
#endif
status = (u32)READ_ONCE(ct->status);
......@@ -2002,9 +2004,9 @@ static void ctnetlink_change_mark(struct nf_conn *ct,
mask = ~ntohl(nla_get_be32(cda[CTA_MARK_MASK]));
mark = ntohl(nla_get_be32(cda[CTA_MARK]));
newmark = (ct->mark & mask) ^ mark;
if (newmark != ct->mark)
ct->mark = newmark;
newmark = (READ_ONCE(ct->mark) & mask) ^ mark;
if (newmark != READ_ONCE(ct->mark))
WRITE_ONCE(ct->mark, newmark);
}
#endif
......@@ -2669,6 +2671,7 @@ static int __ctnetlink_glue_build(struct sk_buff *skb, struct nf_conn *ct)
{
const struct nf_conntrack_zone *zone;
struct nlattr *nest_parms;
u32 mark;
zone = nf_ct_zone(ct);
......@@ -2730,7 +2733,8 @@ static int __ctnetlink_glue_build(struct sk_buff *skb, struct nf_conn *ct)
goto nla_put_failure;
#ifdef CONFIG_NF_CONNTRACK_MARK
if (ct->mark && ctnetlink_dump_mark(skb, ct) < 0)
mark = READ_ONCE(ct->mark);
if (mark && ctnetlink_dump_mark(skb, mark) < 0)
goto nla_put_failure;
#endif
if (ctnetlink_dump_labels(skb, ct) < 0)
......
......@@ -366,7 +366,7 @@ static int ct_seq_show(struct seq_file *s, void *v)
goto release;
#if defined(CONFIG_NF_CONNTRACK_MARK)
seq_printf(s, "mark=%u ", ct->mark);
seq_printf(s, "mark=%u ", READ_ONCE(ct->mark));
#endif
ct_show_secctx(s, ct);
......
......@@ -98,7 +98,7 @@ static void nft_ct_get_eval(const struct nft_expr *expr,
return;
#ifdef CONFIG_NF_CONNTRACK_MARK
case NFT_CT_MARK:
*dest = ct->mark;
*dest = READ_ONCE(ct->mark);
return;
#endif
#ifdef CONFIG_NF_CONNTRACK_SECMARK
......@@ -297,8 +297,8 @@ static void nft_ct_set_eval(const struct nft_expr *expr,
switch (priv->key) {
#ifdef CONFIG_NF_CONNTRACK_MARK
case NFT_CT_MARK:
if (ct->mark != value) {
ct->mark = value;
if (READ_ONCE(ct->mark) != value) {
WRITE_ONCE(ct->mark, value);
nf_conntrack_event_cache(IPCT_MARK, ct);
}
break;
......
......@@ -30,6 +30,7 @@ connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
u_int32_t new_targetmark;
struct nf_conn *ct;
u_int32_t newmark;
u_int32_t oldmark;
ct = nf_ct_get(skb, &ctinfo);
if (ct == NULL)
......@@ -37,14 +38,15 @@ connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
switch (info->mode) {
case XT_CONNMARK_SET:
newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
oldmark = READ_ONCE(ct->mark);
newmark = (oldmark & ~info->ctmask) ^ info->ctmark;
if (info->shift_dir == D_SHIFT_RIGHT)
newmark >>= info->shift_bits;
else
newmark <<= info->shift_bits;
if (ct->mark != newmark) {
ct->mark = newmark;
if (READ_ONCE(ct->mark) != newmark) {
WRITE_ONCE(ct->mark, newmark);
nf_conntrack_event_cache(IPCT_MARK, ct);
}
break;
......@@ -55,15 +57,15 @@ connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
else
new_targetmark <<= info->shift_bits;
newmark = (ct->mark & ~info->ctmask) ^
newmark = (READ_ONCE(ct->mark) & ~info->ctmask) ^
new_targetmark;
if (ct->mark != newmark) {
ct->mark = newmark;
if (READ_ONCE(ct->mark) != newmark) {
WRITE_ONCE(ct->mark, newmark);
nf_conntrack_event_cache(IPCT_MARK, ct);
}
break;
case XT_CONNMARK_RESTORE:
new_targetmark = (ct->mark & info->ctmask);
new_targetmark = (READ_ONCE(ct->mark) & info->ctmask);
if (info->shift_dir == D_SHIFT_RIGHT)
new_targetmark >>= info->shift_bits;
else
......@@ -126,7 +128,7 @@ connmark_mt(const struct sk_buff *skb, struct xt_action_param *par)
if (ct == NULL)
return false;
return ((ct->mark & info->mask) == info->mark) ^ info->invert;
return ((READ_ONCE(ct->mark) & info->mask) == info->mark) ^ info->invert;
}
static int connmark_mt_check(const struct xt_mtchk_param *par)
......
......@@ -152,7 +152,7 @@ static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
static u32 ovs_ct_get_mark(const struct nf_conn *ct)
{
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
return ct ? ct->mark : 0;
return ct ? READ_ONCE(ct->mark) : 0;
#else
return 0;
#endif
......@@ -340,9 +340,9 @@ static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
u32 new_mark;
new_mark = ct_mark | (ct->mark & ~(mask));
if (ct->mark != new_mark) {
ct->mark = new_mark;
new_mark = ct_mark | (READ_ONCE(ct->mark) & ~(mask));
if (READ_ONCE(ct->mark) != new_mark) {
WRITE_ONCE(ct->mark, new_mark);
if (nf_ct_is_confirmed(ct))
nf_conntrack_event_cache(IPCT_MARK, ct);
key->ct.mark = new_mark;
......
......@@ -61,7 +61,7 @@ static int tcf_connmark_act(struct sk_buff *skb, const struct tc_action *a,
c = nf_ct_get(skb, &ctinfo);
if (c) {
skb->mark = c->mark;
skb->mark = READ_ONCE(c->mark);
/* using overlimits stats to count how many packets marked */
ca->tcf_qstats.overlimits++;
goto out;
......@@ -81,7 +81,7 @@ static int tcf_connmark_act(struct sk_buff *skb, const struct tc_action *a,
c = nf_ct_tuplehash_to_ctrack(thash);
/* using overlimits stats to count how many packets marked */
ca->tcf_qstats.overlimits++;
skb->mark = c->mark;
skb->mark = READ_ONCE(c->mark);
nf_ct_put(c);
out:
......
......@@ -178,7 +178,7 @@ static void tcf_ct_flow_table_add_action_meta(struct nf_conn *ct,
entry = tcf_ct_flow_table_flow_action_get_next(action);
entry->id = FLOW_ACTION_CT_METADATA;
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
entry->ct_metadata.mark = ct->mark;
entry->ct_metadata.mark = READ_ONCE(ct->mark);
#endif
ctinfo = dir == IP_CT_DIR_ORIGINAL ? IP_CT_ESTABLISHED :
IP_CT_ESTABLISHED_REPLY;
......@@ -936,9 +936,9 @@ static void tcf_ct_act_set_mark(struct nf_conn *ct, u32 mark, u32 mask)
if (!mask)
return;
new_mark = mark | (ct->mark & ~(mask));
if (ct->mark != new_mark) {
ct->mark = new_mark;
new_mark = mark | (READ_ONCE(ct->mark) & ~(mask));
if (READ_ONCE(ct->mark) != new_mark) {
WRITE_ONCE(ct->mark, new_mark);
if (nf_ct_is_confirmed(ct))
nf_conntrack_event_cache(IPCT_MARK, ct);
}
......
......@@ -32,7 +32,7 @@ static void tcf_ctinfo_dscp_set(struct nf_conn *ct, struct tcf_ctinfo *ca,
{
u8 dscp, newdscp;
newdscp = (((ct->mark & cp->dscpmask) >> cp->dscpmaskshift) << 2) &
newdscp = (((READ_ONCE(ct->mark) & cp->dscpmask) >> cp->dscpmaskshift) << 2) &
~INET_ECN_MASK;
switch (proto) {
......@@ -72,7 +72,7 @@ static void tcf_ctinfo_cpmark_set(struct nf_conn *ct, struct tcf_ctinfo *ca,
struct sk_buff *skb)
{
ca->stats_cpmark_set++;
skb->mark = ct->mark & cp->cpmarkmask;
skb->mark = READ_ONCE(ct->mark) & cp->cpmarkmask;
}
static int tcf_ctinfo_act(struct sk_buff *skb, const struct tc_action *a,
......@@ -130,7 +130,7 @@ static int tcf_ctinfo_act(struct sk_buff *skb, const struct tc_action *a,
}
if (cp->mode & CTINFO_MODE_DSCP)
if (!cp->dscpstatemask || (ct->mark & cp->dscpstatemask))
if (!cp->dscpstatemask || (READ_ONCE(ct->mark) & cp->dscpstatemask))
tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto);
if (cp->mode & CTINFO_MODE_CPMARK)
......
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