From: Gao Feng <fgao@xxxxxxxxxx>
When memory is exhausted, nfct_seqadj_ext_add may fail to add the seqadj
extension. But the function nf_ct_seqadj_init doesn't check if get valid
seqadj pointer by the nfct_seqadj.
Now drop the packet directly when fail to add seqadj extension to avoid
dereference NULL pointer in nf_ct_seqadj_init.
Signed-off-by: Gao Feng <fgao@xxxxxxxxxx>
---
v4: Drop the packet directly when fail to add seqadj extension;
v3: Remove the warning log when seqadj is null;
v2: Remove the unnessary seqadj check in nf_ct_seq_adjust
v1: Initial patch
net/netfilter/nf_conntrack_core.c | 6 +++++-
net/netfilter/nf_nat_core.c | 3 ++-
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index dd2c43a..dfa76ce 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1036,7 +1036,11 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
return (struct nf_conntrack_tuple_hash *)ct;
if (tmpl && nfct_synproxy(tmpl)) {
- nfct_seqadj_ext_add(ct);
+ if (!nfct_seqadj_ext_add(ct)) {
+ nf_conntrack_free(ct);
+ pr_debug("Can't add seqadj extension\n");
+ return NULL;
+ }
nfct_synproxy_ext_add(ct);
}
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index de31818..b82282a 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -441,7 +441,8 @@ nf_nat_setup_info(struct nf_conn *ct,
ct->status |= IPS_DST_NAT;
if (nfct_help(ct))
- nfct_seqadj_ext_add(ct);
+ if (!nfct_seqadj_ext_add(ct))
+ return NF_DROP;
}
if (maniptype == NF_NAT_MANIP_SRC) {
--
1.9.1
--
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