diff options
| author | Fernando Fernandez Mancera <fmancera@suse.de> | 2026-05-26 23:58:29 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2026-06-05 13:11:55 +0200 |
| commit | 992c20bc8a4aba220c8b95b467d049289778dad6 (patch) | |
| tree | a3b9761a87d072893117c8e5a77de57849566dfe | |
| parent | 22bb132cfb9b94847d52d73614284b8c5ea8d36e (diff) | |
netfilter: synproxy: fix unaligned memory access in timestamp adjustment
Use get_unaligned_be32() and put_unaligned_be32() to safely read and
write the timestamp fields. This prevents performance degradation due to
unaligned memory access or even a crash on strict alignment
architectures.
This follows the implementation of timestamp parsing in the networking
stack at tcp_parse_options() and synproxy_parse_options().
Fixes: 48b1de4c110a ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | net/netfilter/nf_synproxy_core.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/net/netfilter/nf_synproxy_core.c b/net/netfilter/nf_synproxy_core.c index a0bcf188810d..acd360515972 100644 --- a/net/netfilter/nf_synproxy_core.c +++ b/net/netfilter/nf_synproxy_core.c @@ -191,7 +191,7 @@ synproxy_tstamp_adjust(struct sk_buff *skb, unsigned int protoff, const struct nf_conn_synproxy *synproxy) { unsigned int optoff, optend; - __be32 *ptr, old; + u32 new, old; if (synproxy->tsoff == 0) return true; @@ -221,18 +221,17 @@ synproxy_tstamp_adjust(struct sk_buff *skb, unsigned int protoff, if (op[0] == TCPOPT_TIMESTAMP && op[1] == TCPOLEN_TIMESTAMP) { if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) { - ptr = (__be32 *)&op[2]; - old = *ptr; - *ptr = htonl(ntohl(*ptr) - - synproxy->tsoff); + old = get_unaligned_be32(&op[2]); + new = old - synproxy->tsoff; + put_unaligned_be32(new, &op[2]); } else { - ptr = (__be32 *)&op[6]; - old = *ptr; - *ptr = htonl(ntohl(*ptr) + - synproxy->tsoff); + old = get_unaligned_be32(&op[6]); + new = old + synproxy->tsoff; + put_unaligned_be32(new, &op[6]); } inet_proto_csum_replace4(&th->check, skb, - old, *ptr, false); + cpu_to_be32(old), + cpu_to_be32(new), false); } optoff += op[1]; } |