diff options
| author | Florian Westphal <fw@strlen.de> | 2017-01-23 18:21:58 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-02-02 14:31:55 +0100 |
| commit | 303223092081963513494b4377fa1ac9e362ed4b (patch) | |
| tree | e312cf241ada3f96d5844613770ebbeeb152585c /net/netfilter | |
| parent | c74454fadd5ea6fc866ffe2c417a0dba56b2bf1c (diff) | |
| download | linux-303223092081963513494b4377fa1ac9e362ed4b.tar.gz linux-303223092081963513494b4377fa1ac9e362ed4b.tar.xz | |
netfilter: guarantee 8 byte minalign for template addresses
The next change will merge skb->nfct pointer and skb->nfctinfo
status bits into single skb->_nfct (unsigned long) area.
For this to work nf_conn addresses must always be aligned at least on
an 8 byte boundary since we will need the lower 3bits to store nfctinfo.
Conntrack templates are allocated via kmalloc.
kbuild test robot reported
BUILD_BUG_ON failed: NFCT_INFOMASK >= ARCH_KMALLOC_MINALIGN
on v1 of this patchset, so not all platforms meet this requirement.
Do manual alignment if needed, the alignment offset is stored in the
nf_conn entry protocol area. This works because templates are not
handed off to L4 protocol trackers.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/nf_conntrack_core.c | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index c9bd10747864..768968fba7f6 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -350,16 +350,31 @@ static void nf_ct_del_from_dying_or_unconfirmed_list(struct nf_conn *ct) spin_unlock(&pcpu->lock); } +#define NFCT_ALIGN(len) (((len) + NFCT_INFOMASK) & ~NFCT_INFOMASK) + /* Released via destroy_conntrack() */ struct nf_conn *nf_ct_tmpl_alloc(struct net *net, const struct nf_conntrack_zone *zone, gfp_t flags) { - struct nf_conn *tmpl; + struct nf_conn *tmpl, *p; - tmpl = kzalloc(sizeof(*tmpl), flags); - if (tmpl == NULL) - return NULL; + if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK) { + tmpl = kzalloc(sizeof(*tmpl) + NFCT_INFOMASK, flags); + if (!tmpl) + return NULL; + + p = tmpl; + tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p); + if (tmpl != p) { + tmpl = (struct nf_conn *)NFCT_ALIGN((unsigned long)p); + tmpl->proto.tmpl_padto = (char *)tmpl - (char *)p; + } + } else { + tmpl = kzalloc(sizeof(*tmpl), flags); + if (!tmpl) + return NULL; + } tmpl->status = IPS_TEMPLATE; write_pnet(&tmpl->ct_net, net); @@ -374,7 +389,11 @@ void nf_ct_tmpl_free(struct nf_conn *tmpl) { nf_ct_ext_destroy(tmpl); nf_ct_ext_free(tmpl); - kfree(tmpl); + + if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK) + kfree((char *)tmpl - tmpl->proto.tmpl_padto); + else + kfree(tmpl); } EXPORT_SYMBOL_GPL(nf_ct_tmpl_free); |