mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-07-22 02:17:36 -04:00
Code Issues Packages Projects Releases Wiki Activity

netfilter: synproxy: fix unaligned memory access in timestamp adjustment

Browse Source 
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: 48b1de4c11 ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Fernando Fernandez Mancera
2026-05-26 23:58:29 +02:00
committed by Pablo Neira Ayuso
parent 22bb132cfb
commit 992c20bc8a
1 changed files with 9 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
net/netfilter/nf_synproxy_core.c
View File

@@ -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];
}