OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

netfilter: ctnetlink: fix mark based dump filtering regression 

conntrack mark based dump filtering may falsely skip entries if a mask
is given: If the mask-based check does not filter out the entry, the
else-if check is always true and compares the mark without considering
the mask. The if/else-if logic seems wrong.

Given that the mask during filter setup is implicitly set to 0xffffffff
if not specified explicitly, the mark filtering flags seem to just
complicate things. Restore the previously used approach by always
matching against a zero mask is no filter mark is given.

Fixes: cb8aa9a3af ("netfilter: ctnetlink: add kernel side filtering for dump")
Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Martin Willi 2020-09-01 08:56:19 +02:00 committed by Pablo Neira Ayuso
parent 67cc570eda
commit 6c0d95d123
1 changed files with 3 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
net/netfilter/nf_conntrack_netlink.c
View File

@ -851,7 +851,6 @@ static int ctnetlink_done(struct netlink_callback *cb)
}
struct ctnetlink_filter {
u_int32_t cta_flags;
u8 family;
u_int32_t orig_flags;
@ -906,10 +905,6 @@ static int ctnetlink_parse_tuple_filter(const struct nlattr * const cda[],
struct nf_conntrack_zone *zone,
u_int32_t flags);
/* applied on filters */
#define CTA_FILTER_F_CTA_MARK (1 << 0)
#define CTA_FILTER_F_CTA_MARK_MASK (1 << 1)
static struct ctnetlink_filter *
ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
{
@ -930,14 +925,10 @@ ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
#ifdef CONFIG_NF_CONNTRACK_MARK
if (cda[CTA_MARK]) {
filter->mark.val = ntohl(nla_get_be32(cda[CTA_MARK]));
filter->cta_flags |= CTA_FILTER_FLAG(CTA_MARK);
if (cda[CTA_MARK_MASK]) {
if (cda[CTA_MARK_MASK])
filter->mark.mask = ntohl(nla_get_be32(cda[CTA_MARK_MASK]));
filter->cta_flags |= CTA_FILTER_FLAG(CTA_MARK_MASK);
} else {
else
filter->mark.mask = 0xffffffff;
}
} else if (cda[CTA_MARK_MASK]) {
err = -EINVAL;
goto err_filter;
@ -1117,11 +1108,7 @@ static int ctnetlink_filter_match(struct nf_conn *ct, void *data)
}
#ifdef CONFIG_NF_CONNTRACK_MARK
if ((filter->cta_flags & CTA_FILTER_FLAG(CTA_MARK_MASK)) &&
(ct->mark & filter->mark.mask) != filter->mark.val)
goto ignore_entry;
else if ((filter->cta_flags & CTA_FILTER_FLAG(CTA_MARK)) &&
ct->mark != filter->mark.val)
if ((ct->mark & filter->mark.mask) != filter->mark.val)
goto ignore_entry;
#endif