From: Arnd Bergmann <arnd@xxxxxxxx>
gcc correctly identified a theoretical uninitialized variable use:
net/netfilter/nf_conntrack_core.c: In function 'nf_conntrack_in':
net/netfilter/nf_conntrack_core.c:1125:14: error: 'l4proto' may be used uninitialized in this function [-Werror=maybe-uninitialized]
This could only happen when we 'goto out' before looking up l4proto,
and then enter the retry, implying that l3proto->get_l4proto()
returned NF_REPEAT. This does not currently get returned in any
code path and probably won't ever happen, but is not good to
rely on.
Moving the repeat handling up a little should have the same
behavior as today but avoids the warning by making that case
impossible to enter.
[ I have mangled this original patch to remove the check for tmpl, we
should inconditionally jump back to the repeat label in case we hit
NF_REPEAT instead. I have also moved the comment that explains this
where it belongs. --pablo ]
Fixes: 08733a0cb7de ("netfilter: handle NF_REPEAT from nf_conntrack_in()")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_conntrack_core.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index de4b8a75f30b..e9ffe33dc0ca 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1337,6 +1337,12 @@ nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
NF_CT_STAT_INC_ATOMIC(net, invalid);
if (ret == -NF_DROP)
NF_CT_STAT_INC_ATOMIC(net, drop);
+ /* Special case: TCP tracker reports an attempt to reopen a
+ * closed/aborted connection. We have to go back and create a
+ * fresh conntrack.
+ */
+ if (ret == -NF_REPEAT)
+ goto repeat;
ret = -ret;
goto out;
}
@@ -1344,16 +1350,8 @@ nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
if (set_reply && !test_and_set_bit(IPS_SEEN_REPLY_BIT, &ct->status))
nf_conntrack_event_cache(IPCT_REPLY, ct);
out:
- if (tmpl) {
- /* Special case: TCP tracker reports an attempt to reopen a
- * closed/aborted connection. We have to go back and create a
- * fresh conntrack.
- */
- if (ret == NF_REPEAT)
- goto repeat;
- else
- nf_ct_put(tmpl);
- }
+ if (tmpl)
+ nf_ct_put(tmpl);
return ret;
}
--
2.1.4
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