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authorLiping Zhang <zlpnobody@gmail.com>2017-05-21 22:38:11 +0800
committerPablo Neira Ayuso <pablo@netfilter.org>2017-05-23 22:54:51 +0200
commit124dffea9e8e372509e055aebd118e85518fd644 (patch)
treeeb35feb6b0c04851d32095b9aa082c0f898c9210 /net/netfilter
parentd2df92e98a34a5619dadd29c6291113c009181e7 (diff)
netfilter: nat: use atomic bit op to clear the _SRC_NAT_DONE_BIT
We need to clear the IPS_SRC_NAT_DONE_BIT to indicate that the ct has been removed from nat_bysource table. But unfortunately, we use the non-atomic bit operation: "ct->status &= ~IPS_NAT_DONE_MASK". So there's a race condition that we may clear the _DYING_BIT set by another CPU unexpectedly. Since we don't care about the IPS_DST_NAT_DONE_BIT, so just using clear_bit to clear the IPS_SRC_NAT_DONE_BIT is enough. Also note, this is the last user which use the non-atomic bit operation to update the confirmed ct->status. Reported-by: Florian Westphal <fw@strlen.de> Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter')
-rw-r--r--net/netfilter/nf_nat_core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index ef0be325a0c6..6c72922d20ca 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -566,7 +566,7 @@ static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
* Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
* will delete entry from already-freed table.
*/
- ct->status &= ~IPS_NAT_DONE_MASK;
+ clear_bit(IPS_SRC_NAT_DONE_BIT, &ct->status);
rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
nf_nat_bysource_params);