Introduce SW acceleration for IP6IP6 tunnels in the netfilter flowtable infrastructure.
--- Lorenzo Bianconi (4): netfilter: Introduce tunnel metadata info in nf_flowtable_ctx struct netfilter: flowtable: Add IP6IP6 rx sw acceleration netfilter: flowtable: Add IP6IP6 tx sw acceleration selftests: netfilter: nft_flowtable.sh: Add IP6IP6 flowtable selftest
net/ipv6/ip6_tunnel.c | 27 +++ net/netfilter/nf_flow_table_ip.c | 239 ++++++++++++++++++--- .../selftests/net/netfilter/nft_flowtable.sh | 62 +++++- 3 files changed, 285 insertions(+), 43 deletions(-) --- base-commit: 0177f0f07886e54e12c6f18fa58f63e63ddd3c58 change-id: 20251201-flowtable-offload-ip6ip6-578b61067648
Best regards,
Introduce sw acceleration for tx path of IP6IP6 tunnels relying on the netfilter flowtable infrastructure. IP6IP6 tx sw acceleration can be tested running the following scenario where the traffic is forwarded between two NICs (eth0 and eth1) and an IP6IP6 tunnel is used to access a remote site (using eth1 as the underlay device):
ETH0 -- TUN0 <==> ETH1 -- [IP network] -- TUN1 (2001:db8:3::2)
$ip addr show 6: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 00:00:22:33:11:55 brd ff:ff:ff:ff:ff:ff inet6 2001:db8:1::2/64 scope global nodad valid_lft forever preferred_lft forever 7: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 00:11:22:33:11:55 brd ff:ff:ff:ff:ff:ff inet6 2001:db8:2::1/64 scope global nodad valid_lft forever preferred_lft forever 8: tun0@NONE: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1480 qdisc noqueue state UNKNOWN group default qlen 1000 link/tunnel6 2001:db8:2::1 peer 2001:db8:2::2 permaddr ce9c:2940:7dcc:: inet6 2002:db8:1::1/64 scope global nodad valid_lft forever preferred_lft forever
$ip -6 route show 2001:db8:1::/64 dev eth0 proto kernel metric 256 pref medium 2001:db8:2::/64 dev eth1 proto kernel metric 256 pref medium 2002:db8:1::/64 dev tun0 proto kernel metric 256 pref medium default via 2002:db8:1::2 dev tun0 metric 1024 pref medium
$nft list ruleset table inet filter { flowtable ft { hook ingress priority filter devices = { eth0, eth1 } }
chain forward { type filter hook forward priority filter; policy accept; meta l4proto { tcp, udp } flow add @ft } }
Reproducing the scenario described above using veths I got the following results: - TCP stream received from the IPIP tunnel: - net-next: (baseline) ~93Gbps - net-next + IP6IP6 flowtbale support: ~98Gbps
Signed-off-by: Lorenzo Bianconi lorenzo@kernel.org --- net/netfilter/nf_flow_table_ip.c | 93 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+)
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index ca5a5d58eb2edbd61fe826eb892eaaf2d5b9e537..e5182630a83e3e959c7bde293ddc3beef295cd51 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -12,6 +12,7 @@ #include <net/ip.h> #include <net/ipv6.h> #include <net/ip6_route.h> +#include <net/ip6_tunnel.h> #include <net/neighbour.h> #include <net/netfilter/nf_flow_table.h> #include <net/netfilter/nf_conntrack_acct.h> @@ -646,6 +647,91 @@ static int nf_flow_tunnel_v4_push(struct net *net, struct sk_buff *skb, return 0; }
+struct ipv6_tel_txoption { + struct ipv6_txoptions ops; + __u8 dst_opt[8]; +}; + +static int nf_flow_tunnel_ip6ip6_push(struct net *net, struct sk_buff *skb, + struct flow_offload_tuple *tuple, + struct in6_addr **ip6_daddr) +{ + struct ipv6hdr *ip6h = (struct ipv6hdr *)skb_network_header(skb); + int err, mtu, encap_limit = IPV6_DEFAULT_TNL_ENCAP_LIMIT; + u8 hop_limit = ip6h->hop_limit, proto = IPPROTO_IPV6; + struct rtable *rt = dst_rtable(tuple->dst_cache); + __u8 dsfield = ipv6_get_dsfield(ip6h); + struct flowi6 fl6 = { + .daddr = tuple->tun.src_v6, + .saddr = tuple->tun.dst_v6, + .flowi6_proto = proto, + }; + u32 headroom; + + err = iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6); + if (err) + return err; + + skb_set_inner_ipproto(skb, proto); + headroom = sizeof(*ip6h) + LL_RESERVED_SPACE(rt->dst.dev) + + rt->dst.header_len; + if (encap_limit) + headroom += 8; + err = skb_cow_head(skb, headroom); + if (err) + return err; + + skb_scrub_packet(skb, true); + mtu = dst_mtu(&rt->dst) - sizeof(*ip6h); + if (encap_limit) + mtu -= 8; + mtu = max(mtu, IPV6_MIN_MTU); + skb_dst_update_pmtu_no_confirm(skb, mtu); + + if (encap_limit > 0) { + struct ipv6_tel_txoption opt = { + .dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT, + .dst_opt[3] = 1, + .dst_opt[4] = encap_limit, + .dst_opt[5] = IPV6_TLV_PADN, + .dst_opt[6] = 1, + }; + + opt.ops.dst1opt = (struct ipv6_opt_hdr *)opt.dst_opt; + opt.ops.opt_nflen = 8; + ipv6_push_frag_opts(skb, &opt.ops, &proto); + } + + skb_push(skb, sizeof(*ip6h)); + skb_reset_network_header(skb); + + ip6h = ipv6_hdr(skb); + ip6_flow_hdr(ip6h, dsfield, + ip6_make_flowlabel(net, skb, fl6.flowlabel, true, &fl6)); + ip6h->hop_limit = hop_limit; + ip6h->nexthdr = proto; + ip6h->daddr = tuple->tun.src_v6; + ip6h->saddr = tuple->tun.dst_v6; + ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(*ip6h)); + IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); + IP6CB(skb)->flags = 0; + memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); + + *ip6_daddr = &tuple->tun.src_v6; + + return 0; +} + +static int nf_flow_tunnel_v6_push(struct net *net, struct sk_buff *skb, + struct flow_offload_tuple *tuple, + struct in6_addr **ip6_daddr) +{ + if (tuple->tun_num) + return nf_flow_tunnel_ip6ip6_push(net, skb, tuple, ip6_daddr); + + return 0; +} + static int nf_flow_encap_push(struct sk_buff *skb, struct flow_offload_tuple *tuple) { @@ -934,6 +1020,9 @@ static int nf_flow_offload_ipv6_forward(struct nf_flowtable_ctx *ctx, flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
mtu = flow->tuplehash[dir].tuple.mtu + ctx->offset; + if (flow->tuplehash[!dir].tuple.tun_num) + mtu -= sizeof(*ip6h); + if (unlikely(nf_flow_exceeds_mtu(skb, mtu))) return 0;
@@ -1023,6 +1112,10 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb, other_tuple = &flow->tuplehash[!dir].tuple; ip6_daddr = &other_tuple->src_v6;
+ if (nf_flow_tunnel_v6_push(state->net, skb, other_tuple, + &ip6_daddr) < 0) + return NF_DROP; + if (nf_flow_encap_push(skb, other_tuple) < 0) return NF_DROP;
Similar to IPIP, introduce specific selftest for IP6IP6 flowtable SW acceleration in nft_flowtable.sh
Signed-off-by: Lorenzo Bianconi lorenzo@kernel.org --- .../selftests/net/netfilter/nft_flowtable.sh | 62 ++++++++++++++++++---- 1 file changed, 53 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/net/netfilter/nft_flowtable.sh b/tools/testing/selftests/net/netfilter/nft_flowtable.sh index a68bc882fa4ec0175d8db3df8337bb5fe6c42e26..14d7f67715edc17ee1917913a3d0f417215200ba 100755 --- a/tools/testing/selftests/net/netfilter/nft_flowtable.sh +++ b/tools/testing/selftests/net/netfilter/nft_flowtable.sh @@ -592,16 +592,28 @@ ip -net "$nsr1" link set tun0 up ip -net "$nsr1" addr add 192.168.100.1/24 dev tun0 ip netns exec "$nsr1" sysctl net.ipv4.conf.tun0.forwarding=1 > /dev/null
+ip -net "$nsr1" link add name tun6 type ip6tnl local fee1:2::1 remote fee1:2::2 +ip -net "$nsr1" link set tun6 up +ip -net "$nsr1" addr add fee1:3::1/64 dev tun6 nodad + ip -net "$nsr2" link add name tun0 type ipip local 192.168.10.2 remote 192.168.10.1 ip -net "$nsr2" link set tun0 up ip -net "$nsr2" addr add 192.168.100.2/24 dev tun0 ip netns exec "$nsr2" sysctl net.ipv4.conf.tun0.forwarding=1 > /dev/null
+ip -net "$nsr2" link add name tun6 type ip6tnl local fee1:2::2 remote fee1:2::1 +ip -net "$nsr2" link set tun6 up +ip -net "$nsr2" addr add fee1:3::2/64 dev tun6 nodad + ip -net "$nsr1" route change default via 192.168.100.2 ip -net "$nsr2" route change default via 192.168.100.1 +ip -6 -net "$nsr1" route change default via fee1:3::2 +ip -6 -net "$nsr2" route change default via fee1:3::1 ip -net "$ns2" route add default via 10.0.2.1 +ip -6 -net "$ns2" route add default via dead:2::1
ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif tun0 accept' +ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif tun6 accept' ip netns exec "$nsr1" nft -a insert rule inet filter forward \ 'meta oif "veth0" tcp sport 12345 ct mark set 1 flow add @f1 counter name routed_repl accept'
@@ -611,28 +623,51 @@ if ! test_tcp_forwarding_nat "$ns1" "$ns2" 1 "IPIP tunnel"; then ret=1 fi
+if test_tcp_forwarding "$ns1" "$ns2" 1 6 "[dead:2::99]" 12345; then + echo "PASS: flow offload for ns1/ns2 IP6IP6 tunnel" +else + echo "FAIL: flow offload for ns1/ns2 with IP6IP6 tunnel" 1>&2 + ip netns exec "$nsr1" nft list ruleset + ret=1 +fi + # Create vlan tagged devices for IPIP traffic. ip -net "$nsr1" link add link veth1 name veth1.10 type vlan id 10 ip -net "$nsr1" link set veth1.10 up ip -net "$nsr1" addr add 192.168.20.1/24 dev veth1.10 +ip -net "$nsr1" addr add fee1:4::1/64 dev veth1.10 nodad ip netns exec "$nsr1" sysctl net.ipv4.conf.veth1/10.forwarding=1 > /dev/null ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif veth1.10 accept' -ip -net "$nsr1" link add name tun1 type ipip local 192.168.20.1 remote 192.168.20.2 -ip -net "$nsr1" link set tun1 up -ip -net "$nsr1" addr add 192.168.200.1/24 dev tun1 + +ip -net "$nsr1" link add name tun0.10 type ipip local 192.168.20.1 remote 192.168.20.2 +ip -net "$nsr1" link set tun0.10 up +ip -net "$nsr1" addr add 192.168.200.1/24 dev tun0.10 ip -net "$nsr1" route change default via 192.168.200.2 -ip netns exec "$nsr1" sysctl net.ipv4.conf.tun1.forwarding=1 > /dev/null -ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif tun1 accept' +ip netns exec "$nsr1" sysctl net.ipv4.conf.tun0/10.forwarding=1 > /dev/null +ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif tun0.10 accept' + +ip -net "$nsr1" link add name tun6.10 type ip6tnl local fee1:4::1 remote fee1:4::2 +ip -net "$nsr1" link set tun6.10 up +ip -net "$nsr1" addr add fee1:5::1/64 dev tun6.10 nodad +ip -6 -net "$nsr1" route change default via fee1:5::2 +ip netns exec "$nsr1" nft -a insert rule inet filter forward 'meta oif tun6.10 accept'
ip -net "$nsr2" link add link veth0 name veth0.10 type vlan id 10 ip -net "$nsr2" link set veth0.10 up ip -net "$nsr2" addr add 192.168.20.2/24 dev veth0.10 +ip -net "$nsr2" addr add fee1:4::2/64 dev veth0.10 nodad ip netns exec "$nsr2" sysctl net.ipv4.conf.veth0/10.forwarding=1 > /dev/null -ip -net "$nsr2" link add name tun1 type ipip local 192.168.20.2 remote 192.168.20.1 -ip -net "$nsr2" link set tun1 up -ip -net "$nsr2" addr add 192.168.200.2/24 dev tun1 + +ip -net "$nsr2" link add name tun0.10 type ipip local 192.168.20.2 remote 192.168.20.1 +ip -net "$nsr2" link set tun0.10 up +ip -net "$nsr2" addr add 192.168.200.2/24 dev tun0.10 ip -net "$nsr2" route change default via 192.168.200.1 -ip netns exec "$nsr2" sysctl net.ipv4.conf.tun1.forwarding=1 > /dev/null +ip netns exec "$nsr2" sysctl net.ipv4.conf.tun0/10.forwarding=1 > /dev/null + +ip -net "$nsr2" link add name tun6.10 type ip6tnl local fee1:4::2 remote fee1:4::1 +ip -net "$nsr2" link set tun6.10 up +ip -net "$nsr2" addr add fee1:5::2/64 dev tun6.10 nodad +ip -6 -net "$nsr2" route change default via fee1:5::1
if ! test_tcp_forwarding_nat "$ns1" "$ns2" 1 "IPIP tunnel over vlan"; then echo "FAIL: flow offload for ns1/ns2 with IPIP tunnel over vlan" 1>&2 @@ -640,10 +675,19 @@ if ! test_tcp_forwarding_nat "$ns1" "$ns2" 1 "IPIP tunnel over vlan"; then ret=1 fi
+if test_tcp_forwarding "$ns1" "$ns2" 1 6 "[dead:2::99]" 12345; then + echo "PASS: flow offload for ns1/ns2 IP6IP6 tunnel over vlan" +else + echo "FAIL: flow offload for ns1/ns2 with IP6IP6 tunnel over vlan" 1>&2 + ip netns exec "$nsr1" nft list ruleset + ret=1 +fi + # Restore the previous configuration ip -net "$nsr1" route change default via 192.168.10.2 ip -net "$nsr2" route change default via 192.168.10.1 ip -net "$ns2" route del default via 10.0.2.1 +ip -6 -net "$ns2" route del default via dead:2::1 }
# Another test:
syzbot ci has tested the following series
[v1] Add IP6IP6 flowtable SW acceleration https://lore.kernel.org/all/20251201-flowtable-offload-ip6ip6-v1-0-1dabf534c... * [PATCH RFC nf-next 1/4] netfilter: Introduce tunnel metadata info in nf_flowtable_ctx struct * [PATCH RFC nf-next 2/4] netfilter: flowtable: Add IP6IP6 rx sw acceleration * [PATCH RFC nf-next 3/4] netfilter: flowtable: Add IP6IP6 tx sw acceleration * [PATCH RFC nf-next 4/4] selftests: netfilter: nft_flowtable.sh: Add IP6IP6 flowtable selftest
and found the following issue: KASAN: slab-use-after-free Read in nf_flow_skb_encap_protocol
Full report is available here: https://ci.syzbot.org/series/df395c22-6768-4a9f-9a96-56b5307acbc6
***
KASAN: slab-use-after-free Read in nf_flow_skb_encap_protocol
tree: nf-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netfilter/nf-next.g... base: ff736a286116d462a4067ba258fa351bc0b4ed80 arch: amd64 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 config: https://ci.syzbot.org/builds/018f7259-7abc-4b77-b40c-e8e520e1e793/config C repro: https://ci.syzbot.org/findings/5cb5bc43-721b-4a9e-a093-4d52aab5ba9f/c_repro syz repro: https://ci.syzbot.org/findings/5cb5bc43-721b-4a9e-a093-4d52aab5ba9f/syz_repr...
================================================================== BUG: KASAN: slab-use-after-free in nf_flow_ip6_tunnel_proto net/netfilter/nf_flow_table_ip.c:383 [inline] BUG: KASAN: slab-use-after-free in nf_flow_skb_encap_protocol+0x1336/0x14e0 net/netfilter/nf_flow_table_ip.c:433 Read of size 2 at addr ffff888115de92b6 by task syz.0.20/5970
CPU: 0 UID: 0 PID: 5970 Comm: syz.0.20 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 nf_flow_ip6_tunnel_proto net/netfilter/nf_flow_table_ip.c:383 [inline] nf_flow_skb_encap_protocol+0x1336/0x14e0 net/netfilter/nf_flow_table_ip.c:433 nf_flow_offload_ipv6_lookup net/netfilter/nf_flow_table_ip.c:1065 [inline] nf_flow_offload_ipv6_hook+0x131/0x3380 net/netfilter/nf_flow_table_ip.c:1092 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline] nf_ingress net/core/dev.c:5900 [inline] __netif_receive_skb_core+0x241c/0x2f90 net/core/dev.c:5996 __netif_receive_skb_one_core net/core/dev.c:6135 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6250 netif_receive_skb_internal net/core/dev.c:6336 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6395 tun_rx_batched+0x1b9/0x730 drivers/net/tun.c:1485 tun_get_user+0x2b65/0x3e90 drivers/net/tun.c:1953 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8b24f8f7c9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8b25e26038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f8b251e6090 RCX: 00007f8b24f8f7c9 RDX: 000000000000fdef RSI: 0000200000000440 RDI: 0000000000000003 RBP: 00007f8b24ff297f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8b251e6128 R14: 00007f8b251e6090 R15: 00007ffe014b8a38 </TASK>
Allocated by task 5970: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5340 __alloc_skb+0x255/0x430 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6712 sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2995 tun_alloc_skb drivers/net/tun.c:1461 [inline] tun_get_user+0xa43/0x3e90 drivers/net/tun.c:1794 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 5970: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2543 [inline] slab_free mm/slub.c:6642 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6752 icmpv6_param_prob include/linux/icmpv6.h:95 [inline] ipv6_rthdr_rcv+0x150e/0x2020 net/ipv6/exthdrs.c:828 nf_flow_ip6_tunnel_proto net/netfilter/nf_flow_table_ip.c:381 [inline] nf_flow_skb_encap_protocol+0x9b5/0x14e0 net/netfilter/nf_flow_table_ip.c:433 nf_flow_offload_ipv6_lookup net/netfilter/nf_flow_table_ip.c:1065 [inline] nf_flow_offload_ipv6_hook+0x131/0x3380 net/netfilter/nf_flow_table_ip.c:1092 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline] nf_ingress net/core/dev.c:5900 [inline] __netif_receive_skb_core+0x241c/0x2f90 net/core/dev.c:5996 __netif_receive_skb_one_core net/core/dev.c:6135 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6250 netif_receive_skb_internal net/core/dev.c:6336 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6395 tun_rx_batched+0x1b9/0x730 drivers/net/tun.c:1485 tun_get_user+0x2b65/0x3e90 drivers/net/tun.c:1953 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888115de9200 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 182 bytes inside of freed 240-byte region [ffff888115de9200, ffff888115de92f0)
The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x115de8 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 017ff00000000040 ffff8881036ba8c0 ffffea0004280a80 dead000000000002 raw: 0000000000000000 0000000080150015 00000000f5000000 0000000000000000 head: 017ff00000000040 ffff8881036ba8c0 ffffea0004280a80 dead000000000002 head: 0000000000000000 0000000080150015 00000000f5000000 0000000000000000 head: 017ff00000000001 ffffea0004577a01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5555, tgid 5555 (dhcpcd), ts 36767395595, free_ts 35122573404 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5178 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3059 [inline] allocate_slab+0x96/0x350 mm/slub.c:3232 new_slab mm/slub.c:3286 [inline] ___slab_alloc+0xf56/0x1990 mm/slub.c:4655 __slab_alloc+0x65/0x100 mm/slub.c:4778 __slab_alloc_node mm/slub.c:4854 [inline] slab_alloc_node mm/slub.c:5276 [inline] kmem_cache_alloc_node_noprof+0x4c5/0x710 mm/slub.c:5340 __alloc_skb+0x255/0x430 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6712 sock_alloc_send_pskb+0x84d/0x980 net/core/sock.c:2995 unix_dgram_sendmsg+0x454/0x1840 net/unix/af_unix.c:2139 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 do_iter_readv_writev+0x623/0x8c0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 page last free pid 5262 tgid 5262 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2901 __slab_free+0x2e7/0x390 mm/slub.c:5970 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5295 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2924 [inline] do_sys_openat2+0xbc/0x1c0 fs/open.c:1431 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address: ffff888115de9180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888115de9200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888115de9280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
^ ffff888115de9300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888115de9380: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================
***
If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: syzbot@syzkaller.appspotmail.com
--- This report is generated by a bot. It may contain errors. syzbot ci engineers can be reached at syzkaller@googlegroups.com.
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