linux-stable.git/net/ipv6/netfilter, branch v6.6.78

netfilter: nf_reject_ipv6: fix potential crash in nf_send_reset6()

2024-11-08T15:28:19+00:00

[ Upstream commit 4ed234fe793f27a3b151c43d2106df2ff0d81aac ]

I got a syzbot report without a repro [1] crashing in nf_send_reset6()

I think the issue is that dev->hard_header_len is zero, and we attempt
later to push an Ethernet header.

Use LL_MAX_HEADER, as other functions in net/ipv6/netfilter/nf_reject_ipv6.c.

[1]

skbuff: skb_under_panic: text:ffffffff89b1d008 len:74 put:14 head:ffff88803123aa00 data:ffff88803123a9f2 tail:0x3c end:0x140 dev:syz_tun
 kernel BUG at net/core/skbuff.c:206 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 7373 Comm: syz.1.568 Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
 RIP: 0010:skb_panic net/core/skbuff.c:206 [inline]
 RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216
Code: 0d 8d 48 c7 c6 60 a6 29 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 ba 30 38 02 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc900045269b0 EFLAGS: 00010282
RAX: 0000000000000088 RBX: dffffc0000000000 RCX: cd66dacdc5d8e800
RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000
RBP: ffff88802d39a3d0 R08: ffffffff8174afec R09: 1ffff920008a4ccc
R10: dffffc0000000000 R11: fffff520008a4ccd R12: 0000000000000140
R13: ffff88803123aa00 R14: ffff88803123a9f2 R15: 000000000000003c
FS:  00007fdbee5ff6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005d322000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
  skb_push+0xe5/0x100 net/core/skbuff.c:2636
  eth_header+0x38/0x1f0 net/ethernet/eth.c:83
  dev_hard_header include/linux/netdevice.h:3208 [inline]
  nf_send_reset6+0xce6/0x1270 net/ipv6/netfilter/nf_reject_ipv6.c:358
  nft_reject_inet_eval+0x3b9/0x690 net/netfilter/nft_reject_inet.c:48
  expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
  nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288
  nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161
  nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
  nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626
  nf_hook include/linux/netfilter.h:269 [inline]
  NF_HOOK include/linux/netfilter.h:312 [inline]
  br_nf_pre_routing_ipv6+0x63e/0x770 net/bridge/br_netfilter_ipv6.c:184
  nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
  nf_hook_bridge_pre net/bridge/br_input.c:277 [inline]
  br_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424
  __netif_receive_skb_core+0x13e8/0x4570 net/core/dev.c:5562
  __netif_receive_skb_one_core net/core/dev.c:5666 [inline]
  __netif_receive_skb+0x12f/0x650 net/core/dev.c:5781
  netif_receive_skb_internal net/core/dev.c:5867 [inline]
  netif_receive_skb+0x1e8/0x890 net/core/dev.c:5926
  tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1550
  tun_get_user+0x3056/0x47e0 drivers/net/tun.c:2007
  tun_chr_write_iter+0x10d/0x1f0 drivers/net/tun.c:2053
  new_sync_write fs/read_write.c:590 [inline]
  vfs_write+0xa6d/0xc90 fs/read_write.c:683
  ksys_write+0x183/0x2b0 fs/read_write.c:736
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdbeeb7d1ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 1c 8e 02 00 48
RSP: 002b:00007fdbee5ff000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdbeed36058 RCX: 00007fdbeeb7d1ff
RDX: 000000000000008e RSI: 0000000020000040 RDI: 00000000000000c8
RBP: 00007fdbeebf12be R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000008e R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdbeed36058 R15: 00007ffc38de06e8
 

Fixes: c8d7b98bec43 ("netfilter: move nf_send_resetX() code to nf_reject_ipvX modules")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: fib: check correct rtable in vrf setups

2024-10-17T13:24:28+00:00

[ Upstream commit 05ef7055debc804e8083737402127975e7244fc4 ]

We need to init l3mdev unconditionally, else main routing table is searched
and incorrect result is returned unless strict (iif keyword) matching is
requested.

Next patch adds a selftest for this.

Fixes: 2a8a7c0eaa87 ("netfilter: nft_fib: Fix for rpath check with VRF devices")
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1761
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_reject: Fix build warning when CONFIG_BRIDGE_NETFILTER=n

2024-10-17T13:24:20+00:00

[ Upstream commit fc56878ca1c288e49b5cbb43860a5938e3463654 ]

If CONFIG_BRIDGE_NETFILTER is not enabled, which is the case for x86_64
defconfig, then building nf_reject_ipv4.c and nf_reject_ipv6.c with W=1
using gcc-14 results in the following warnings, which are treated as
errors:

net/ipv4/netfilter/nf_reject_ipv4.c: In function 'nf_send_reset':
net/ipv4/netfilter/nf_reject_ipv4.c:243:23: error: variable 'niph' set but not used [-Werror=unused-but-set-variable]
  243 |         struct iphdr *niph;
      |                       ^~~~
cc1: all warnings being treated as errors
net/ipv6/netfilter/nf_reject_ipv6.c: In function 'nf_send_reset6':
net/ipv6/netfilter/nf_reject_ipv6.c:286:25: error: variable 'ip6h' set but not used [-Werror=unused-but-set-variable]
  286 |         struct ipv6hdr *ip6h;
      |                         ^~~~
cc1: all warnings being treated as errors

Address this by reducing the scope of these local variables to where
they are used, which is code only compiled when CONFIG_BRIDGE_NETFILTER
enabled.

Compile tested and run through netfilter selftests.

Reported-by: Andy Shevchenko 
Closes: https://lore.kernel.org/netfilter-devel/20240906145513.567781-1-andriy.shevchenko@linux.intel.com/
Signed-off-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_tables: prevent nf_skb_duplicated corruption

2024-10-10T09:57:15+00:00

[ Upstream commit 92ceba94de6fb4cee2bf40b485979c342f44a492 ]

syzbot found that nf_dup_ipv4() or nf_dup_ipv6() could write
per-cpu variable nf_skb_duplicated in an unsafe way [1].

Disabling preemption as hinted by the splat is not enough,
we have to disable soft interrupts as well.

[1]
BUG: using __this_cpu_write() in preemptible [00000000] code: syz.4.282/6316
 caller is nf_dup_ipv4+0x651/0x8f0 net/ipv4/netfilter/nf_dup_ipv4.c:87
CPU: 0 UID: 0 PID: 6316 Comm: syz.4.282 Not tainted 6.11.0-rc7-syzkaller-00104-g7052622fccb1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 
  __dump_stack lib/dump_stack.c:93 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
  check_preemption_disabled+0x10e/0x120 lib/smp_processor_id.c:49
  nf_dup_ipv4+0x651/0x8f0 net/ipv4/netfilter/nf_dup_ipv4.c:87
  nft_dup_ipv4_eval+0x1db/0x300 net/ipv4/netfilter/nft_dup_ipv4.c:30
  expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
  nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288
  nft_do_chain_ipv4+0x202/0x320 net/netfilter/nft_chain_filter.c:23
  nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
  nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626
  nf_hook+0x2c4/0x450 include/linux/netfilter.h:269
  NF_HOOK_COND include/linux/netfilter.h:302 [inline]
  ip_output+0x185/0x230 net/ipv4/ip_output.c:433
  ip_local_out net/ipv4/ip_output.c:129 [inline]
  ip_send_skb+0x74/0x100 net/ipv4/ip_output.c:1495
  udp_send_skb+0xacf/0x1650 net/ipv4/udp.c:981
  udp_sendmsg+0x1c21/0x2a60 net/ipv4/udp.c:1269
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x1a6/0x270 net/socket.c:745
  ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
  ___sys_sendmsg net/socket.c:2651 [inline]
  __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737
  __do_sys_sendmmsg net/socket.c:2766 [inline]
  __se_sys_sendmmsg net/socket.c:2763 [inline]
  __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4ce4f7def9
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:00007f4ce5d4a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f4ce5135f80 RCX: 00007f4ce4f7def9
RDX: 0000000000000001 RSI: 0000000020005d40 RDI: 0000000000000006
RBP: 00007f4ce4ff0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4ce5135f80 R15: 00007ffd4cbc6d68
 

Fixes: d877f07112f1 ("netfilter: nf_tables: add nft_dup expression")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_reject_ipv6: fix nf_reject_ip6_tcphdr_put()

2024-10-04T14:29:41+00:00

[ Upstream commit 9c778fe48d20ef362047e3376dee56d77f8500d4 ]

syzbot reported that nf_reject_ip6_tcphdr_put() was possibly sending
garbage on the four reserved tcp bits (th->res1)

Use skb_put_zero() to clear the whole TCP header,
as done in nf_reject_ip_tcphdr_put()

BUG: KMSAN: uninit-value in nf_reject_ip6_tcphdr_put+0x688/0x6c0 net/ipv6/netfilter/nf_reject_ipv6.c:255
  nf_reject_ip6_tcphdr_put+0x688/0x6c0 net/ipv6/netfilter/nf_reject_ipv6.c:255
  nf_send_reset6+0xd84/0x15b0 net/ipv6/netfilter/nf_reject_ipv6.c:344
  nft_reject_inet_eval+0x3c1/0x880 net/netfilter/nft_reject_inet.c:48
  expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
  nft_do_chain+0x438/0x22a0 net/netfilter/nf_tables_core.c:288
  nft_do_chain_inet+0x41a/0x4f0 net/netfilter/nft_chain_filter.c:161
  nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
  nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626
  nf_hook include/linux/netfilter.h:269 [inline]
  NF_HOOK include/linux/netfilter.h:312 [inline]
  ipv6_rcv+0x29b/0x390 net/ipv6/ip6_input.c:310
  __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
  __netif_receive_skb+0x1da/0xa00 net/core/dev.c:5775
  process_backlog+0x4ad/0xa50 net/core/dev.c:6108
  __napi_poll+0xe7/0x980 net/core/dev.c:6772
  napi_poll net/core/dev.c:6841 [inline]
  net_rx_action+0xa5a/0x19b0 net/core/dev.c:6963
  handle_softirqs+0x1ce/0x800 kernel/softirq.c:554
  __do_softirq+0x14/0x1a kernel/softirq.c:588
  do_softirq+0x9a/0x100 kernel/softirq.c:455
  __local_bh_enable_ip+0x9f/0xb0 kernel/softirq.c:382
  local_bh_enable include/linux/bottom_half.h:33 [inline]
  rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline]
  __dev_queue_xmit+0x2692/0x5610 net/core/dev.c:4450
  dev_queue_xmit include/linux/netdevice.h:3105 [inline]
  neigh_resolve_output+0x9ca/0xae0 net/core/neighbour.c:1565
  neigh_output include/net/neighbour.h:542 [inline]
  ip6_finish_output2+0x2347/0x2ba0 net/ipv6/ip6_output.c:141
  __ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
  ip6_finish_output+0xbb8/0x14b0 net/ipv6/ip6_output.c:226
  NF_HOOK_COND include/linux/netfilter.h:303 [inline]
  ip6_output+0x356/0x620 net/ipv6/ip6_output.c:247
  dst_output include/net/dst.h:450 [inline]
  NF_HOOK include/linux/netfilter.h:314 [inline]
  ip6_xmit+0x1ba6/0x25d0 net/ipv6/ip6_output.c:366
  inet6_csk_xmit+0x442/0x530 net/ipv6/inet6_connection_sock.c:135
  __tcp_transmit_skb+0x3b07/0x4880 net/ipv4/tcp_output.c:1466
  tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline]
  tcp_connect+0x35b6/0x7130 net/ipv4/tcp_output.c:4143
  tcp_v6_connect+0x1bcc/0x1e40 net/ipv6/tcp_ipv6.c:333
  __inet_stream_connect+0x2ef/0x1730 net/ipv4/af_inet.c:679
  inet_stream_connect+0x6a/0xd0 net/ipv4/af_inet.c:750
  __sys_connect_file net/socket.c:2061 [inline]
  __sys_connect+0x606/0x690 net/socket.c:2078
  __do_sys_connect net/socket.c:2088 [inline]
  __se_sys_connect net/socket.c:2085 [inline]
  __x64_sys_connect+0x91/0xe0 net/socket.c:2085
  x64_sys_call+0x27a5/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:43
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
  nf_reject_ip6_tcphdr_put+0x60c/0x6c0 net/ipv6/netfilter/nf_reject_ipv6.c:249
  nf_send_reset6+0xd84/0x15b0 net/ipv6/netfilter/nf_reject_ipv6.c:344
  nft_reject_inet_eval+0x3c1/0x880 net/netfilter/nft_reject_inet.c:48
  expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
  nft_do_chain+0x438/0x22a0 net/netfilter/nf_tables_core.c:288
  nft_do_chain_inet+0x41a/0x4f0 net/netfilter/nft_chain_filter.c:161
  nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
  nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626
  nf_hook include/linux/netfilter.h:269 [inline]
  NF_HOOK include/linux/netfilter.h:312 [inline]
  ipv6_rcv+0x29b/0x390 net/ipv6/ip6_input.c:310
  __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
  __netif_receive_skb+0x1da/0xa00 net/core/dev.c:5775
  process_backlog+0x4ad/0xa50 net/core/dev.c:6108
  __napi_poll+0xe7/0x980 net/core/dev.c:6772
  napi_poll net/core/dev.c:6841 [inline]
  net_rx_action+0xa5a/0x19b0 net/core/dev.c:6963
  handle_softirqs+0x1ce/0x800 kernel/softirq.c:554
  __do_softirq+0x14/0x1a kernel/softirq.c:588

Uninit was stored to memory at:
  nf_reject_ip6_tcphdr_put+0x2ca/0x6c0 net/ipv6/netfilter/nf_reject_ipv6.c:231
  nf_send_reset6+0xd84/0x15b0 net/ipv6/netfilter/nf_reject_ipv6.c:344
  nft_reject_inet_eval+0x3c1/0x880 net/netfilter/nft_reject_inet.c:48
  expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
  nft_do_chain+0x438/0x22a0 net/netfilter/nf_tables_core.c:288
  nft_do_chain_inet+0x41a/0x4f0 net/netfilter/nft_chain_filter.c:161
  nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
  nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626
  nf_hook include/linux/netfilter.h:269 [inline]
  NF_HOOK include/linux/netfilter.h:312 [inline]
  ipv6_rcv+0x29b/0x390 net/ipv6/ip6_input.c:310
  __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
  __netif_receive_skb+0x1da/0xa00 net/core/dev.c:5775
  process_backlog+0x4ad/0xa50 net/core/dev.c:6108
  __napi_poll+0xe7/0x980 net/core/dev.c:6772
  napi_poll net/core/dev.c:6841 [inline]
  net_rx_action+0xa5a/0x19b0 net/core/dev.c:6963
  handle_softirqs+0x1ce/0x800 kernel/softirq.c:554
  __do_softirq+0x14/0x1a kernel/softirq.c:588

Uninit was created at:
  slab_post_alloc_hook mm/slub.c:3998 [inline]
  slab_alloc_node mm/slub.c:4041 [inline]
  kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4084
  kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:583
  __alloc_skb+0x363/0x7b0 net/core/skbuff.c:674
  alloc_skb include/linux/skbuff.h:1320 [inline]
  nf_send_reset6+0x98d/0x15b0 net/ipv6/netfilter/nf_reject_ipv6.c:327
  nft_reject_inet_eval+0x3c1/0x880 net/netfilter/nft_reject_inet.c:48
  expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
  nft_do_chain+0x438/0x22a0 net/netfilter/nf_tables_core.c:288
  nft_do_chain_inet+0x41a/0x4f0 net/netfilter/nft_chain_filter.c:161
  nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
  nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626
  nf_hook include/linux/netfilter.h:269 [inline]
  NF_HOOK include/linux/netfilter.h:312 [inline]
  ipv6_rcv+0x29b/0x390 net/ipv6/ip6_input.c:310
  __netif_receive_skb_one_core net/core/dev.c:5661 [inline]
  __netif_receive_skb+0x1da/0xa00 net/core/dev.c:5775
  process_backlog+0x4ad/0xa50 net/core/dev.c:6108
  __napi_poll+0xe7/0x980 net/core/dev.c:6772
  napi_poll net/core/dev.c:6841 [inline]
  net_rx_action+0xa5a/0x19b0 net/core/dev.c:6963
  handle_softirqs+0x1ce/0x800 kernel/softirq.c:554
  __do_softirq+0x14/0x1a kernel/softirq.c:588

Fixes: c8d7b98bec43 ("netfilter: move nf_send_resetX() code to nf_reject_ipvX modules")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Reviewed-by: Pablo Neira Ayuso 
Link: https://patch.msgid.link/20240913170615.3670897-1-edumazet@google.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

netfilter: allow ipv6 fragments to arrive on different devices

2024-08-29T15:33:19+00:00

[ Upstream commit 3cd740b985963f874a1a094f1969e998b9d05554 ]

Commit 264640fc2c5f4 ("ipv6: distinguish frag queues by device
for multicast and link-local packets") modified the ipv6 fragment
reassembly logic to distinguish frag queues by device for multicast
and link-local packets but in fact only the main reassembly code
limits the use of the device to those address types and the netfilter
reassembly code uses the device for all packets.

This means that if fragments of a packet arrive on different interfaces
then netfilter will fail to reassemble them and the fragments will be
expired without going any further through the filters.

Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units")
Signed-off-by: Tom Hughes 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: iptables: Fix potential null-ptr-deref in ip6table_nat_table_init().

2024-08-11T10:47:22+00:00

[ Upstream commit c22921df777de5606f1047b1345b8d22ef1c0b34 ]

ip6table_nat_table_init() accesses net->gen->ptr[ip6table_nat_net_ops.id],
but the function is exposed to user space before the entry is allocated
via register_pernet_subsys().

Let's call register_pernet_subsys() before xt_register_template().

Fixes: fdacd57c79b7 ("netfilter: x_tables: never register tables by default")
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: complete validation of user input

2024-04-17T09:19:30+00:00

[ Upstream commit 65acf6e0501ac8880a4f73980d01b5d27648b956 ]

In my recent commit, I missed that do_replace() handlers
use copy_from_sockptr() (which I fixed), followed
by unsafe copy_from_sockptr_offset() calls.

In all functions, we can perform the @optlen validation
before even calling xt_alloc_table_info() with the following
check:

if ((u64)optlen < (u64)tmp.size + sizeof(tmp))
        return -EINVAL;

Fixes: 0c83842df40f ("netfilter: validate user input for expected length")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Pablo Neira Ayuso 
Link: https://lore.kernel.org/r/20240409120741.3538135-1-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

netfilter: validate user input for expected length

2024-04-10T14:35:51+00:00

commit 0c83842df40f86e529db6842231154772c20edcc upstream.

I got multiple syzbot reports showing old bugs exposed
by BPF after commit 20f2505fb436 ("bpf: Try to avoid kzalloc
in cgroup/{s,g}etsockopt")

setsockopt() @optlen argument should be taken into account
before copying data.

 BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
 BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline]
 BUG: KASAN: slab-out-of-bounds in do_replace net/ipv4/netfilter/ip_tables.c:1111 [inline]
 BUG: KASAN: slab-out-of-bounds in do_ipt_set_ctl+0x902/0x3dd0 net/ipv4/netfilter/ip_tables.c:1627
Read of size 96 at addr ffff88802cd73da0 by task syz-executor.4/7238

CPU: 1 PID: 7238 Comm: syz-executor.4 Not tainted 6.9.0-rc2-next-20240403-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
  print_address_description mm/kasan/report.c:377 [inline]
  print_report+0x169/0x550 mm/kasan/report.c:488
  kasan_report+0x143/0x180 mm/kasan/report.c:601
  kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
  __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
  copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
  copy_from_sockptr include/linux/sockptr.h:55 [inline]
  do_replace net/ipv4/netfilter/ip_tables.c:1111 [inline]
  do_ipt_set_ctl+0x902/0x3dd0 net/ipv4/netfilter/ip_tables.c:1627
  nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101
  do_sock_setsockopt+0x3af/0x720 net/socket.c:2311
  __sys_setsockopt+0x1ae/0x250 net/socket.c:2334
  __do_sys_setsockopt net/socket.c:2343 [inline]
  __se_sys_setsockopt net/socket.c:2340 [inline]
  __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x72/0x7a
RIP: 0033:0x7fd22067dde9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd21f9ff0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fd2207abf80 RCX: 00007fd22067dde9
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fd2206ca47a R08: 0000000000000001 R09: 0000000000000000
R10: 0000000020000880 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fd2207abf80 R15: 00007ffd2d0170d8
 

Allocated by task 7238:
  kasan_save_stack mm/kasan/common.c:47 [inline]
  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
  poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
  __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
  kasan_kmalloc include/linux/kasan.h:211 [inline]
  __do_kmalloc_node mm/slub.c:4069 [inline]
  __kmalloc_noprof+0x200/0x410 mm/slub.c:4082
  kmalloc_noprof include/linux/slab.h:664 [inline]
  __cgroup_bpf_run_filter_setsockopt+0xd47/0x1050 kernel/bpf/cgroup.c:1869
  do_sock_setsockopt+0x6b4/0x720 net/socket.c:2293
  __sys_setsockopt+0x1ae/0x250 net/socket.c:2334
  __do_sys_setsockopt net/socket.c:2343 [inline]
  __se_sys_setsockopt net/socket.c:2340 [inline]
  __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

The buggy address belongs to the object at ffff88802cd73da0
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes inside of
 allocated 1-byte region [ffff88802cd73da0, ffff88802cd73da1)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802cd73020 pfn:0x2cd73
flags: 0xfff80000000000(node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffefff(slab)
raw: 00fff80000000000 ffff888015041280 dead000000000100 dead000000000122
raw: ffff88802cd73020 000000008080007f 00000001ffffefff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5103, tgid 2119833701 (syz-executor.4), ts 5103, free_ts 70804600828
  set_page_owner include/linux/page_owner.h:32 [inline]
  post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1490
  prep_new_page mm/page_alloc.c:1498 [inline]
  get_page_from_freelist+0x2e7e/0x2f40 mm/page_alloc.c:3454
  __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4712
  __alloc_pages_node_noprof include/linux/gfp.h:244 [inline]
  alloc_pages_node_noprof include/linux/gfp.h:271 [inline]
  alloc_slab_page+0x5f/0x120 mm/slub.c:2249
  allocate_slab+0x5a/0x2e0 mm/slub.c:2412
  new_slab mm/slub.c:2465 [inline]
  ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3615
  __slab_alloc+0x58/0xa0 mm/slub.c:3705
  __slab_alloc_node mm/slub.c:3758 [inline]
  slab_alloc_node mm/slub.c:3936 [inline]
  __do_kmalloc_node mm/slub.c:4068 [inline]
  kmalloc_node_track_caller_noprof+0x286/0x450 mm/slub.c:4089
  kstrdup+0x3a/0x80 mm/util.c:62
  device_rename+0xb5/0x1b0 drivers/base/core.c:4558
  dev_change_name+0x275/0x860 net/core/dev.c:1232
  do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2864
  __rtnl_newlink net/core/rtnetlink.c:3680 [inline]
  rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3727
  rtnetlink_rcv_msg+0x89b/0x10d0 net/core/rtnetlink.c:6594
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2559
  netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
  netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
page last free pid 5146 tgid 5146 stack trace:
  reset_page_owner include/linux/page_owner.h:25 [inline]
  free_pages_prepare mm/page_alloc.c:1110 [inline]
  free_unref_page+0xd3c/0xec0 mm/page_alloc.c:2617
  discard_slab mm/slub.c:2511 [inline]
  __put_partials+0xeb/0x130 mm/slub.c:2980
  put_cpu_partial+0x17c/0x250 mm/slub.c:3055
  __slab_free+0x2ea/0x3d0 mm/slub.c:4254
  qlink_free mm/kasan/quarantine.c:163 [inline]
  qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
  kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
  __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
  kasan_slab_alloc include/linux/kasan.h:201 [inline]
  slab_post_alloc_hook mm/slub.c:3888 [inline]
  slab_alloc_node mm/slub.c:3948 [inline]
  __do_kmalloc_node mm/slub.c:4068 [inline]
  __kmalloc_node_noprof+0x1d7/0x450 mm/slub.c:4076
  kmalloc_node_noprof include/linux/slab.h:681 [inline]
  kvmalloc_node_noprof+0x72/0x190 mm/util.c:634
  bucket_table_alloc lib/rhashtable.c:186 [inline]
  rhashtable_rehash_alloc+0x9e/0x290 lib/rhashtable.c:367
  rht_deferred_worker+0x4e1/0x2440 lib/rhashtable.c:427
  process_one_work kernel/workqueue.c:3218 [inline]
  process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
  worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
  kthread+0x2f0/0x390 kernel/kthread.c:388
  ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

Memory state around the buggy address:
 ffff88802cd73c80: 07 fc fc fc 05 fc fc fc 05 fc fc fc fa fc fc fc
 ffff88802cd73d00: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc
>ffff88802cd73d80: fa fc fc fc 01 fc fc fc fa fc fc fc fa fc fc fc
                               ^
 ffff88802cd73e00: fa fc fc fc fa fc fc fc 05 fc fc fc 07 fc fc fc
 ffff88802cd73e80: 07 fc fc fc 07 fc fc fc 07 fc fc fc 07 fc fc fc

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Pablo Neira Ayuso 
Link: https://lore.kernel.org/r/20240404122051.2303764-1-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

inet: inet_defrag: prevent sk release while still in use

2024-04-10T14:35:44+00:00

[ Upstream commit 18685451fc4e546fc0e718580d32df3c0e5c8272 ]

ip_local_out() and other functions can pass skb->sk as function argument.

If the skb is a fragment and reassembly happens before such function call
returns, the sk must not be released.

This affects skb fragments reassembled via netfilter or similar
modules, e.g. openvswitch or ct_act.c, when run as part of tx pipeline.

Eric Dumazet made an initial analysis of this bug.  Quoting Eric:
  Calling ip_defrag() in output path is also implying skb_orphan(),
  which is buggy because output path relies on sk not disappearing.

  A relevant old patch about the issue was :
  8282f27449bf ("inet: frag: Always orphan skbs inside ip_defrag()")

  [..]

  net/ipv4/ip_output.c depends on skb->sk being set, and probably to an
  inet socket, not an arbitrary one.

  If we orphan the packet in ipvlan, then downstream things like FQ
  packet scheduler will not work properly.

  We need to change ip_defrag() to only use skb_orphan() when really
  needed, ie whenever frag_list is going to be used.

Eric suggested to stash sk in fragment queue and made an initial patch.
However there is a problem with this:

If skb is refragmented again right after, ip_do_fragment() will copy
head->sk to the new fragments, and sets up destructor to sock_wfree.
IOW, we have no choice but to fix up sk_wmem accouting to reflect the
fully reassembled skb, else wmem will underflow.

This change moves the orphan down into the core, to last possible moment.
As ip_defrag_offset is aliased with sk_buff->sk member, we must move the
offset into the FRAG_CB, else skb->sk gets clobbered.

This allows to delay the orphaning long enough to learn if the skb has
to be queued or if the skb is completing the reasm queue.

In the former case, things work as before, skb is orphaned.  This is
safe because skb gets queued/stolen and won't continue past reasm engine.

In the latter case, we will steal the skb->sk reference, reattach it to
the head skb, and fix up wmem accouting when inet_frag inflates truesize.

Fixes: 7026b1ddb6b8 ("netfilter: Pass socket pointer down through okfn().")
Diagnosed-by: Eric Dumazet 
Reported-by: xingwei lee 
Reported-by: yue sun 
Reported-by: syzbot+e5167d7144a62715044c@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20240326101845.30836-1-fw@strlen.de
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin