From: Florian Westphal fw@strlen.de
commit 399a14ec7993d605740de7b2cd5c0ce8407d12ed upstream.
do not access info->pkt when info->trace is not 1. nft_traceinfo is not initialized, except when tracing is enabled.
The 'nft_trace_enabled' static key cannot be used for this, we must always check info->trace first.
Pass nft_pktinfo directly to avoid this.
Fixes: e34b9ed96ce3 ("netfilter: nf_tables: avoid skb access on nf_stolen") Reported-by: Hangbin Liu liuhangbin@gmail.com Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/nf_tables_core.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c index 3ddce24ac76d..cee3e4e905ec 100644 --- a/net/netfilter/nf_tables_core.c +++ b/net/netfilter/nf_tables_core.c @@ -34,25 +34,23 @@ static noinline void __nft_trace_packet(struct nft_traceinfo *info, nft_trace_notify(info); }
-static inline void nft_trace_packet(struct nft_traceinfo *info, +static inline void nft_trace_packet(const struct nft_pktinfo *pkt, + struct nft_traceinfo *info, const struct nft_chain *chain, const struct nft_rule_dp *rule, enum nft_trace_types type) { if (static_branch_unlikely(&nft_trace_enabled)) { - const struct nft_pktinfo *pkt = info->pkt; - info->nf_trace = pkt->skb->nf_trace; info->rule = rule; __nft_trace_packet(info, chain, type); } }
-static inline void nft_trace_copy_nftrace(struct nft_traceinfo *info) +static inline void nft_trace_copy_nftrace(const struct nft_pktinfo *pkt, + struct nft_traceinfo *info) { if (static_branch_unlikely(&nft_trace_enabled)) { - const struct nft_pktinfo *pkt = info->pkt; - if (info->trace) info->nf_trace = pkt->skb->nf_trace; } @@ -96,7 +94,6 @@ static noinline void __nft_trace_verdict(struct nft_traceinfo *info, const struct nft_chain *chain, const struct nft_regs *regs) { - const struct nft_pktinfo *pkt = info->pkt; enum nft_trace_types type;
switch (regs->verdict.code) { @@ -110,7 +107,9 @@ static noinline void __nft_trace_verdict(struct nft_traceinfo *info, break; default: type = NFT_TRACETYPE_RULE; - info->nf_trace = pkt->skb->nf_trace; + + if (info->trace) + info->nf_trace = info->pkt->skb->nf_trace; break; }
@@ -271,10 +270,10 @@ nft_do_chain(struct nft_pktinfo *pkt, void *priv) switch (regs.verdict.code) { case NFT_BREAK: regs.verdict.code = NFT_CONTINUE; - nft_trace_copy_nftrace(&info); + nft_trace_copy_nftrace(pkt, &info); continue; case NFT_CONTINUE: - nft_trace_packet(&info, chain, rule, + nft_trace_packet(pkt, &info, chain, rule, NFT_TRACETYPE_RULE); continue; } @@ -318,7 +317,7 @@ nft_do_chain(struct nft_pktinfo *pkt, void *priv) goto next_rule; }
- nft_trace_packet(&info, basechain, NULL, NFT_TRACETYPE_POLICY); + nft_trace_packet(pkt, &info, basechain, NULL, NFT_TRACETYPE_POLICY);
if (static_branch_unlikely(&nft_counters_enabled)) nft_update_chain_stats(basechain, pkt);