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: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Daniel Xu 2022-11-09 12:39:07 -07:00 committed by Pablo Neira Ayuso
parent 40b9d1ab63
commit 52d1aa8b82
11 changed files with 45 additions and 39 deletions

View File

@ -296,7 +296,7 @@ skb_flow_dissect_ct(const struct sk_buff *skb,
key->ct_zone = ct->zone.id; key->ct_zone = ct->zone.id;
#endif #endif
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
key->ct_mark = ct->mark; key->ct_mark = READ_ONCE(ct->mark);
#endif #endif
cl = nf_ct_labels_find(ct); cl = nf_ct_labels_find(ct);

View File

@ -435,7 +435,7 @@ clusterip_tg(struct sk_buff *skb, const struct xt_action_param *par)
switch (ctinfo) { switch (ctinfo) {
case IP_CT_NEW: case IP_CT_NEW:
ct->mark = hash; WRITE_ONCE(ct->mark, hash);
break; break;
case IP_CT_RELATED: case IP_CT_RELATED:
case IP_CT_RELATED_REPLY: case IP_CT_RELATED_REPLY:
@ -452,7 +452,7 @@ clusterip_tg(struct sk_buff *skb, const struct xt_action_param *par)
#ifdef DEBUG #ifdef DEBUG
nf_ct_dump_tuple_ip(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); nf_ct_dump_tuple_ip(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
#endif #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)) { if (!clusterip_responsible(cipinfo->config, hash)) {
pr_debug("not responsible\n"); pr_debug("not responsible\n");
return NF_DROP; return NF_DROP;

View File

@ -1781,7 +1781,7 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
} }
#ifdef CONFIG_NF_CONNTRACK_MARK #ifdef CONFIG_NF_CONNTRACK_MARK
ct->mark = exp->master->mark; ct->mark = READ_ONCE(exp->master->mark);
#endif #endif
#ifdef CONFIG_NF_CONNTRACK_SECMARK #ifdef CONFIG_NF_CONNTRACK_SECMARK
ct->secmark = exp->master->secmark; ct->secmark = exp->master->secmark;

View File

@ -328,9 +328,9 @@ nla_put_failure:
} }
#ifdef CONFIG_NF_CONNTRACK_MARK #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; goto nla_put_failure;
return 0; 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) static int ctnetlink_dump_info(struct sk_buff *skb, struct nf_conn *ct)
{ {
if (ctnetlink_dump_status(skb, ct) < 0 || 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_secctx(skb, ct) < 0 ||
ctnetlink_dump_id(skb, ct) < 0 || ctnetlink_dump_id(skb, ct) < 0 ||
ctnetlink_dump_use(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; struct sk_buff *skb;
unsigned int type; unsigned int type;
unsigned int flags = 0, group; unsigned int flags = 0, group;
u32 mark;
int err; int err;
if (events & (1 << IPCT_DESTROY)) { 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 #ifdef CONFIG_NF_CONNTRACK_MARK
if ((events & (1 << IPCT_MARK) || ct->mark) mark = READ_ONCE(ct->mark);
&& ctnetlink_dump_mark(skb, ct) < 0) if ((events & (1 << IPCT_MARK) || mark) &&
ctnetlink_dump_mark(skb, mark) < 0)
goto nla_put_failure; goto nla_put_failure;
#endif #endif
nlmsg_end(skb, nlh); nlmsg_end(skb, nlh);
@ -1154,7 +1156,7 @@ static int ctnetlink_filter_match(struct nf_conn *ct, void *data)
} }
#ifdef CONFIG_NF_CONNTRACK_MARK #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; goto ignore_entry;
#endif #endif
status = (u32)READ_ONCE(ct->status); 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])); mask = ~ntohl(nla_get_be32(cda[CTA_MARK_MASK]));
mark = ntohl(nla_get_be32(cda[CTA_MARK])); mark = ntohl(nla_get_be32(cda[CTA_MARK]));
newmark = (ct->mark & mask) ^ mark; newmark = (READ_ONCE(ct->mark) & mask) ^ mark;
if (newmark != ct->mark) if (newmark != READ_ONCE(ct->mark))
ct->mark = newmark; WRITE_ONCE(ct->mark, newmark);
} }
#endif #endif
@ -2669,6 +2671,7 @@ static int __ctnetlink_glue_build(struct sk_buff *skb, struct nf_conn *ct)
{ {
const struct nf_conntrack_zone *zone; const struct nf_conntrack_zone *zone;
struct nlattr *nest_parms; struct nlattr *nest_parms;
u32 mark;
zone = nf_ct_zone(ct); 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; goto nla_put_failure;
#ifdef CONFIG_NF_CONNTRACK_MARK #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; goto nla_put_failure;
#endif #endif
if (ctnetlink_dump_labels(skb, ct) < 0) if (ctnetlink_dump_labels(skb, ct) < 0)

View File

@ -366,7 +366,7 @@ static int ct_seq_show(struct seq_file *s, void *v)
goto release; goto release;
#if defined(CONFIG_NF_CONNTRACK_MARK) #if defined(CONFIG_NF_CONNTRACK_MARK)
seq_printf(s, "mark=%u ", ct->mark); seq_printf(s, "mark=%u ", READ_ONCE(ct->mark));
#endif #endif
ct_show_secctx(s, ct); ct_show_secctx(s, ct);

View File

@ -98,7 +98,7 @@ static void nft_ct_get_eval(const struct nft_expr *expr,
return; return;
#ifdef CONFIG_NF_CONNTRACK_MARK #ifdef CONFIG_NF_CONNTRACK_MARK
case NFT_CT_MARK: case NFT_CT_MARK:
*dest = ct->mark; *dest = READ_ONCE(ct->mark);
return; return;
#endif #endif
#ifdef CONFIG_NF_CONNTRACK_SECMARK #ifdef CONFIG_NF_CONNTRACK_SECMARK
@ -297,8 +297,8 @@ static void nft_ct_set_eval(const struct nft_expr *expr,
switch (priv->key) { switch (priv->key) {
#ifdef CONFIG_NF_CONNTRACK_MARK #ifdef CONFIG_NF_CONNTRACK_MARK
case NFT_CT_MARK: case NFT_CT_MARK:
if (ct->mark != value) { if (READ_ONCE(ct->mark) != value) {
ct->mark = value; WRITE_ONCE(ct->mark, value);
nf_conntrack_event_cache(IPCT_MARK, ct); nf_conntrack_event_cache(IPCT_MARK, ct);
} }
break; break;

View File

@ -30,6 +30,7 @@ connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
u_int32_t new_targetmark; u_int32_t new_targetmark;
struct nf_conn *ct; struct nf_conn *ct;
u_int32_t newmark; u_int32_t newmark;
u_int32_t oldmark;
ct = nf_ct_get(skb, &ctinfo); ct = nf_ct_get(skb, &ctinfo);
if (ct == NULL) if (ct == NULL)
@ -37,14 +38,15 @@ connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
switch (info->mode) { switch (info->mode) {
case XT_CONNMARK_SET: 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) if (info->shift_dir == D_SHIFT_RIGHT)
newmark >>= info->shift_bits; newmark >>= info->shift_bits;
else else
newmark <<= info->shift_bits; newmark <<= info->shift_bits;
if (ct->mark != newmark) { if (READ_ONCE(ct->mark) != newmark) {
ct->mark = newmark; WRITE_ONCE(ct->mark, newmark);
nf_conntrack_event_cache(IPCT_MARK, ct); nf_conntrack_event_cache(IPCT_MARK, ct);
} }
break; break;
@ -55,15 +57,15 @@ connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
else else
new_targetmark <<= info->shift_bits; new_targetmark <<= info->shift_bits;
newmark = (ct->mark & ~info->ctmask) ^ newmark = (READ_ONCE(ct->mark) & ~info->ctmask) ^
new_targetmark; new_targetmark;
if (ct->mark != newmark) { if (READ_ONCE(ct->mark) != newmark) {
ct->mark = newmark; WRITE_ONCE(ct->mark, newmark);
nf_conntrack_event_cache(IPCT_MARK, ct); nf_conntrack_event_cache(IPCT_MARK, ct);
} }
break; break;
case XT_CONNMARK_RESTORE: 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) if (info->shift_dir == D_SHIFT_RIGHT)
new_targetmark >>= info->shift_bits; new_targetmark >>= info->shift_bits;
else else
@ -126,7 +128,7 @@ connmark_mt(const struct sk_buff *skb, struct xt_action_param *par)
if (ct == NULL) if (ct == NULL)
return false; 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) static int connmark_mt_check(const struct xt_mtchk_param *par)

View File

@ -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) static u32 ovs_ct_get_mark(const struct nf_conn *ct)
{ {
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
return ct ? ct->mark : 0; return ct ? READ_ONCE(ct->mark) : 0;
#else #else
return 0; return 0;
#endif #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) #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
u32 new_mark; u32 new_mark;
new_mark = ct_mark | (ct->mark & ~(mask)); new_mark = ct_mark | (READ_ONCE(ct->mark) & ~(mask));
if (ct->mark != new_mark) { if (READ_ONCE(ct->mark) != new_mark) {
ct->mark = new_mark; WRITE_ONCE(ct->mark, new_mark);
if (nf_ct_is_confirmed(ct)) if (nf_ct_is_confirmed(ct))
nf_conntrack_event_cache(IPCT_MARK, ct); nf_conntrack_event_cache(IPCT_MARK, ct);
key->ct.mark = new_mark; key->ct.mark = new_mark;

View File

@ -61,7 +61,7 @@ static int tcf_connmark_act(struct sk_buff *skb, const struct tc_action *a,
c = nf_ct_get(skb, &ctinfo); c = nf_ct_get(skb, &ctinfo);
if (c) { if (c) {
skb->mark = c->mark; skb->mark = READ_ONCE(c->mark);
/* using overlimits stats to count how many packets marked */ /* using overlimits stats to count how many packets marked */
ca->tcf_qstats.overlimits++; ca->tcf_qstats.overlimits++;
goto out; 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); c = nf_ct_tuplehash_to_ctrack(thash);
/* using overlimits stats to count how many packets marked */ /* using overlimits stats to count how many packets marked */
ca->tcf_qstats.overlimits++; ca->tcf_qstats.overlimits++;
skb->mark = c->mark; skb->mark = READ_ONCE(c->mark);
nf_ct_put(c); nf_ct_put(c);
out: out:

View File

@ -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 = tcf_ct_flow_table_flow_action_get_next(action);
entry->id = FLOW_ACTION_CT_METADATA; entry->id = FLOW_ACTION_CT_METADATA;
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
entry->ct_metadata.mark = ct->mark; entry->ct_metadata.mark = READ_ONCE(ct->mark);
#endif #endif
ctinfo = dir == IP_CT_DIR_ORIGINAL ? IP_CT_ESTABLISHED : ctinfo = dir == IP_CT_DIR_ORIGINAL ? IP_CT_ESTABLISHED :
IP_CT_ESTABLISHED_REPLY; 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) if (!mask)
return; return;
new_mark = mark | (ct->mark & ~(mask)); new_mark = mark | (READ_ONCE(ct->mark) & ~(mask));
if (ct->mark != new_mark) { if (READ_ONCE(ct->mark) != new_mark) {
ct->mark = new_mark; WRITE_ONCE(ct->mark, new_mark);
if (nf_ct_is_confirmed(ct)) if (nf_ct_is_confirmed(ct))
nf_conntrack_event_cache(IPCT_MARK, ct); nf_conntrack_event_cache(IPCT_MARK, ct);
} }

View File

@ -32,7 +32,7 @@ static void tcf_ctinfo_dscp_set(struct nf_conn *ct, struct tcf_ctinfo *ca,
{ {
u8 dscp, newdscp; u8 dscp, newdscp;
newdscp = (((ct->mark & cp->dscpmask) >> cp->dscpmaskshift) << 2) & newdscp = (((READ_ONCE(ct->mark) & cp->dscpmask) >> cp->dscpmaskshift) << 2) &
~INET_ECN_MASK; ~INET_ECN_MASK;
switch (proto) { switch (proto) {
@ -72,7 +72,7 @@ static void tcf_ctinfo_cpmark_set(struct nf_conn *ct, struct tcf_ctinfo *ca,
struct sk_buff *skb) struct sk_buff *skb)
{ {
ca->stats_cpmark_set++; 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, 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->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); tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto);
if (cp->mode & CTINFO_MODE_CPMARK) if (cp->mode & CTINFO_MODE_CPMARK)