6.17-stable review patch. If anyone has any objections, please let me know.
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From: Fernando Fernandez Mancera fmancera@suse.de
[ Upstream commit 09efbac953f6f076a07735f9ba885148d4796235 ]
During a batch replay, the nlh pointer is not reset until the parsing of the commands. Since commit bf2ac490d28c ("netfilter: nfnetlink: Handle ACK flags for batch messages") that is problematic as the condition to add an ACK for batch begin will evaluate to true even if NLM_F_ACK wasn't used for batch begin message.
If there is an error during the command processing, netlink is sending an ACK despite that. This misleads userspace tools which think that the return code was 0. Reset the nlh pointer to the original one when a replay is triggered.
Fixes: bf2ac490d28c ("netfilter: nfnetlink: Handle ACK flags for batch messages") Signed-off-by: Fernando Fernandez Mancera fmancera@suse.de Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nfnetlink.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index e598a2a252b0a..811d02b4c4f7c 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -376,6 +376,7 @@ static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, const struct nfnetlink_subsystem *ss; const struct nfnl_callback *nc; struct netlink_ext_ack extack; + struct nlmsghdr *onlh = nlh; LIST_HEAD(err_list); u32 status; int err; @@ -386,6 +387,7 @@ static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, status = 0; replay_abort: skb = netlink_skb_clone(oskb, GFP_KERNEL); + nlh = onlh; if (!skb) return netlink_ack(oskb, nlh, -ENOMEM, NULL);