From dc21c6cc3d6986d938efbf95de62473982c98dec Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 15 May 2024 13:23:39 +0000 Subject: [PATCH 1/6] netfilter: nfnetlink_queue: acquire rcu_read_lock() in instance_destroy_rcu() syzbot reported that nf_reinject() could be called without rcu_read_lock() : WARNING: suspicious RCU usage 6.9.0-rc7-syzkaller-02060-g5c1672705a1a #0 Not tainted net/netfilter/nfnetlink_queue.c:263 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz-executor.4/13427: #0: ffffffff8e334f60 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e334f60 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2190 [inline] #0: ffffffff8e334f60 (rcu_callback){....}-{0:0}, at: rcu_core+0xa86/0x1830 kernel/rcu/tree.c:2471 #1: ffff88801ca92958 (&inst->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #1: ffff88801ca92958 (&inst->lock){+.-.}-{2:2}, at: nfqnl_flush net/netfilter/nfnetlink_queue.c:405 [inline] #1: ffff88801ca92958 (&inst->lock){+.-.}-{2:2}, at: instance_destroy_rcu+0x30/0x220 net/netfilter/nfnetlink_queue.c:172 stack backtrace: CPU: 0 PID: 13427 Comm: syz-executor.4 Not tainted 6.9.0-rc7-syzkaller-02060-g5c1672705a1a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712 nf_reinject net/netfilter/nfnetlink_queue.c:323 [inline] nfqnl_reinject+0x6ec/0x1120 net/netfilter/nfnetlink_queue.c:397 nfqnl_flush net/netfilter/nfnetlink_queue.c:410 [inline] instance_destroy_rcu+0x1ae/0x220 net/netfilter/nfnetlink_queue.c:172 rcu_do_batch kernel/rcu/tree.c:2196 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471 handle_softirqs+0x2d6/0x990 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 Fixes: 9872bec773c2 ("[NETFILTER]: nfnetlink: use RCU for queue instances hash") Reported-by: syzbot Signed-off-by: Eric Dumazet Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nfnetlink_queue.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 00f4bd21c59b41..f1c31757e4969e 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -169,7 +169,9 @@ instance_destroy_rcu(struct rcu_head *head) struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance, rcu); + rcu_read_lock(); nfqnl_flush(inst, NULL, 0); + rcu_read_unlock(); kfree(inst); module_put(THIS_MODULE); } From c1193d9bbbd379defe9be3c6de566de684de8a6f Mon Sep 17 00:00:00 2001 From: Alexander Maltsev Date: Wed, 17 Apr 2024 18:51:41 +0500 Subject: [PATCH 2/6] netfilter: ipset: Add list flush to cancel_gc Flushing list in cancel_gc drops references to other lists right away, without waiting for RCU to destroy list. Fixes race when referenced ipsets can't be destroyed while referring list is scheduled for destroy. Fixes: 97f7cf1cd80e ("netfilter: ipset: fix performance regression in swap operation") Signed-off-by: Alexander Maltsev Acked-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_list_set.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/ipset/ip_set_list_set.c b/net/netfilter/ipset/ip_set_list_set.c index 6c3f28bc59b325..54e2a1dd7f5f51 100644 --- a/net/netfilter/ipset/ip_set_list_set.c +++ b/net/netfilter/ipset/ip_set_list_set.c @@ -549,6 +549,9 @@ list_set_cancel_gc(struct ip_set *set) if (SET_WITH_TIMEOUT(set)) timer_shutdown_sync(&map->gc); + + /* Flush list to drop references to other ipsets */ + list_set_flush(set); } static const struct ip_set_type_variant set_variant = { From aff5c01fa1284d606f8e7cbdaafeef2511bb46c1 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 9 May 2024 23:02:24 +0200 Subject: [PATCH 3/6] netfilter: nft_payload: restore vlan q-in-q match support Revert f6ae9f120dad ("netfilter: nft_payload: add C-VLAN support"). f41f72d09ee1 ("netfilter: nft_payload: simplify vlan header handling") already allows to match on inner vlan tags by subtract the vlan header size to the payload offset which has been popped and stored in skbuff metadata fields. Fixes: f6ae9f120dad ("netfilter: nft_payload: add C-VLAN support") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_payload.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 0a689c8e0295df..a3cb5dbcb362cc 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -45,36 +45,27 @@ nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len) int mac_off = skb_mac_header(skb) - skb->data; u8 *vlanh, *dst_u8 = (u8 *) d; struct vlan_ethhdr veth; - u8 vlan_hlen = 0; - - if ((skb->protocol == htons(ETH_P_8021AD) || - skb->protocol == htons(ETH_P_8021Q)) && - offset >= VLAN_ETH_HLEN && offset < VLAN_ETH_HLEN + VLAN_HLEN) - vlan_hlen += VLAN_HLEN; vlanh = (u8 *) &veth; - if (offset < VLAN_ETH_HLEN + vlan_hlen) { + if (offset < VLAN_ETH_HLEN) { u8 ethlen = len; - if (vlan_hlen && - skb_copy_bits(skb, mac_off, &veth, VLAN_ETH_HLEN) < 0) - return false; - else if (!nft_payload_rebuild_vlan_hdr(skb, mac_off, &veth)) + if (!nft_payload_rebuild_vlan_hdr(skb, mac_off, &veth)) return false; - if (offset + len > VLAN_ETH_HLEN + vlan_hlen) - ethlen -= offset + len - VLAN_ETH_HLEN - vlan_hlen; + if (offset + len > VLAN_ETH_HLEN) + ethlen -= offset + len - VLAN_ETH_HLEN; - memcpy(dst_u8, vlanh + offset - vlan_hlen, ethlen); + memcpy(dst_u8, vlanh + offset, ethlen); len -= ethlen; if (len == 0) return true; dst_u8 += ethlen; - offset = ETH_HLEN + vlan_hlen; + offset = ETH_HLEN; } else { - offset -= VLAN_HLEN + vlan_hlen; + offset -= VLAN_HLEN; } return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0; From 33c563ebf8d3deed7d8addd20d77398ac737ef9a Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 8 May 2024 22:50:34 +0200 Subject: [PATCH 4/6] netfilter: nft_payload: skbuff vlan metadata mangle support Userspace assumes vlan header is present at a given offset, but vlan offload allows to store this in metadata fields of the skbuff. Hence mangling vlan results in a garbled packet. Handle this transparently by adding a parser to the kernel. If vlan metadata is present and payload offset is over 12 bytes (source and destination mac address fields), then subtract vlan header present in vlan metadata, otherwise mangle vlan metadata based on offset and length, extracting data from the source register. This is similar to: 8cfd23e67401 ("netfilter: nft_payload: work around vlan header stripping") to deal with vlan payload mangling. Fixes: 7ec3f7b47b8d ("netfilter: nft_payload: add packet mangling support") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_payload.c | 72 +++++++++++++++++++++++++++++++++---- 1 file changed, 65 insertions(+), 7 deletions(-) diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index a3cb5dbcb362cc..0c43d748e23ae1 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -145,12 +145,12 @@ int nft_payload_inner_offset(const struct nft_pktinfo *pkt) return pkt->inneroff; } -static bool nft_payload_need_vlan_copy(const struct nft_payload *priv) +static bool nft_payload_need_vlan_adjust(u32 offset, u32 len) { - unsigned int len = priv->offset + priv->len; + unsigned int boundary = offset + len; /* data past ether src/dst requested, copy needed */ - if (len > offsetof(struct ethhdr, h_proto)) + if (boundary > offsetof(struct ethhdr, h_proto)) return true; return false; @@ -174,7 +174,7 @@ void nft_payload_eval(const struct nft_expr *expr, goto err; if (skb_vlan_tag_present(skb) && - nft_payload_need_vlan_copy(priv)) { + nft_payload_need_vlan_adjust(priv->offset, priv->len)) { if (!nft_payload_copy_vlan(dest, skb, priv->offset, priv->len)) goto err; @@ -801,21 +801,79 @@ struct nft_payload_set { u8 csum_flags; }; +/* This is not struct vlan_hdr. */ +struct nft_payload_vlan_hdr { + __be16 h_vlan_proto; + __be16 h_vlan_TCI; +}; + +static bool +nft_payload_set_vlan(const u32 *src, struct sk_buff *skb, u8 offset, u8 len, + int *vlan_hlen) +{ + struct nft_payload_vlan_hdr *vlanh; + __be16 vlan_proto; + u16 vlan_tci; + + if (offset >= offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto)) { + *vlan_hlen = VLAN_HLEN; + return true; + } + + switch (offset) { + case offsetof(struct vlan_ethhdr, h_vlan_proto): + if (len == 2) { + vlan_proto = nft_reg_load_be16(src); + skb->vlan_proto = vlan_proto; + } else if (len == 4) { + vlanh = (struct nft_payload_vlan_hdr *)src; + __vlan_hwaccel_put_tag(skb, vlanh->h_vlan_proto, + ntohs(vlanh->h_vlan_TCI)); + } else { + return false; + } + break; + case offsetof(struct vlan_ethhdr, h_vlan_TCI): + if (len != 2) + return false; + + vlan_tci = ntohs(nft_reg_load_be16(src)); + skb->vlan_tci = vlan_tci; + break; + default: + return false; + } + + return true; +} + static void nft_payload_set_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) { const struct nft_payload_set *priv = nft_expr_priv(expr); - struct sk_buff *skb = pkt->skb; const u32 *src = ®s->data[priv->sreg]; - int offset, csum_offset; + int offset, csum_offset, vlan_hlen = 0; + struct sk_buff *skb = pkt->skb; __wsum fsum, tsum; switch (priv->base) { case NFT_PAYLOAD_LL_HEADER: if (!skb_mac_header_was_set(skb)) goto err; - offset = skb_mac_header(skb) - skb->data; + + if (skb_vlan_tag_present(skb) && + nft_payload_need_vlan_adjust(priv->offset, priv->len)) { + if (!nft_payload_set_vlan(src, skb, + priv->offset, priv->len, + &vlan_hlen)) + goto err; + + if (!vlan_hlen) + return; + } + + offset = skb_mac_header(skb) - skb->data - vlan_hlen; break; case NFT_PAYLOAD_NETWORK_HEADER: offset = skb_network_offset(skb); From 21a673bddc8fd4873c370caf9ae70ffc6d47e8d3 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 13 May 2024 12:27:15 +0200 Subject: [PATCH 5/6] netfilter: tproxy: bail out if IP has been disabled on the device syzbot reports: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] [..] RIP: 0010:nf_tproxy_laddr4+0xb7/0x340 net/ipv4/netfilter/nf_tproxy_ipv4.c:62 Call Trace: nft_tproxy_eval_v4 net/netfilter/nft_tproxy.c:56 [inline] nft_tproxy_eval+0xa9a/0x1a00 net/netfilter/nft_tproxy.c:168 __in_dev_get_rcu() can return NULL, so check for this. Reported-and-tested-by: syzbot+b94a6818504ea90d7661@syzkaller.appspotmail.com Fixes: cc6eb4338569 ("tproxy: use the interface primary IP address as a default value for --on-ip") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv4/netfilter/nf_tproxy_ipv4.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/netfilter/nf_tproxy_ipv4.c b/net/ipv4/netfilter/nf_tproxy_ipv4.c index 69e33179960430..73e66a088e25eb 100644 --- a/net/ipv4/netfilter/nf_tproxy_ipv4.c +++ b/net/ipv4/netfilter/nf_tproxy_ipv4.c @@ -58,6 +58,8 @@ __be32 nf_tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr) laddr = 0; indev = __in_dev_get_rcu(skb->dev); + if (!indev) + return daddr; in_dev_for_each_ifa_rcu(ifa, indev) { if (ifa->ifa_flags & IFA_F_SECONDARY) From e8ded22ef0f4831279c363c264cd41cd9d59ca9e Mon Sep 17 00:00:00 2001 From: Eric Garver Date: Tue, 21 May 2024 10:25:05 -0400 Subject: [PATCH 6/6] netfilter: nft_fib: allow from forward/input without iif selector This removes the restriction of needing iif selector in the forward/input hooks for fib lookups when requested result is oif/oifname. Removing this restriction allows "loose" lookups from the forward hooks. Fixes: be8be04e5ddb ("netfilter: nft_fib: reverse path filter for policy-based routing on iif") Signed-off-by: Eric Garver Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_fib.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/net/netfilter/nft_fib.c b/net/netfilter/nft_fib.c index 37cfe6dd712d8b..b58f62195ff3ee 100644 --- a/net/netfilter/nft_fib.c +++ b/net/netfilter/nft_fib.c @@ -35,11 +35,9 @@ int nft_fib_validate(const struct nft_ctx *ctx, const struct nft_expr *expr, switch (priv->result) { case NFT_FIB_RESULT_OIF: case NFT_FIB_RESULT_OIFNAME: - hooks = (1 << NF_INET_PRE_ROUTING); - if (priv->flags & NFTA_FIB_F_IIF) { - hooks |= (1 << NF_INET_LOCAL_IN) | - (1 << NF_INET_FORWARD); - } + hooks = (1 << NF_INET_PRE_ROUTING) | + (1 << NF_INET_LOCAL_IN) | + (1 << NF_INET_FORWARD); break; case NFT_FIB_RESULT_ADDRTYPE: if (priv->flags & NFTA_FIB_F_IIF)