linux/net/ipv6
Eric Dumazet faa389b2fb ipv6: prevent UAF in ip6_send_skb()
syzbot reported an UAF in ip6_send_skb() [1]

After ip6_local_out() has returned, we no longer can safely
dereference rt, unless we hold rcu_read_lock().

A similar issue has been fixed in commit
a688caa34b ("ipv6: take rcu lock in rawv6_send_hdrinc()")

Another potential issue in ip6_finish_output2() is handled in a
separate patch.

[1]
 BUG: KASAN: slab-use-after-free in ip6_send_skb+0x18d/0x230 net/ipv6/ip6_output.c:1964
Read of size 8 at addr ffff88806dde4858 by task syz.1.380/6530

CPU: 1 UID: 0 PID: 6530 Comm: syz.1.380 Not tainted 6.11.0-rc3-syzkaller-00306-gdf6cbc62cc9b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:93 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
  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
  ip6_send_skb+0x18d/0x230 net/ipv6/ip6_output.c:1964
  rawv6_push_pending_frames+0x75c/0x9e0 net/ipv6/raw.c:588
  rawv6_sendmsg+0x19c7/0x23c0 net/ipv6/raw.c:926
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x1a6/0x270 net/socket.c:745
  sock_write_iter+0x2dd/0x400 net/socket.c:1160
 do_iter_readv_writev+0x60a/0x890
  vfs_writev+0x37c/0xbb0 fs/read_write.c:971
  do_writev+0x1b1/0x350 fs/read_write.c:1018
  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: 0033:0x7f936bf79e79
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:00007f936cd7f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f936c115f80 RCX: 00007f936bf79e79
RDX: 0000000000000001 RSI: 0000000020000040 RDI: 0000000000000004
RBP: 00007f936bfe7916 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f936c115f80 R15: 00007fff2860a7a8
 </TASK>

Allocated by task 6530:
  kasan_save_stack mm/kasan/common.c:47 [inline]
  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
  unpoison_slab_object mm/kasan/common.c:312 [inline]
  __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
  kasan_slab_alloc include/linux/kasan.h:201 [inline]
  slab_post_alloc_hook mm/slub.c:3988 [inline]
  slab_alloc_node mm/slub.c:4037 [inline]
  kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4044
  dst_alloc+0x12b/0x190 net/core/dst.c:89
  ip6_blackhole_route+0x59/0x340 net/ipv6/route.c:2670
  make_blackhole net/xfrm/xfrm_policy.c:3120 [inline]
  xfrm_lookup_route+0xd1/0x1c0 net/xfrm/xfrm_policy.c:3313
  ip6_dst_lookup_flow+0x13e/0x180 net/ipv6/ip6_output.c:1257
  rawv6_sendmsg+0x1283/0x23c0 net/ipv6/raw.c:898
  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_sendmsg+0x2b0/0x3a0 net/socket.c:2680
  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

Freed by task 45:
  kasan_save_stack mm/kasan/common.c:47 [inline]
  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
  kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
  poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
  __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
  kasan_slab_free include/linux/kasan.h:184 [inline]
  slab_free_hook mm/slub.c:2252 [inline]
  slab_free mm/slub.c:4473 [inline]
  kmem_cache_free+0x145/0x350 mm/slub.c:4548
  dst_destroy+0x2ac/0x460 net/core/dst.c:124
  rcu_do_batch kernel/rcu/tree.c:2569 [inline]
  rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2843
  handle_softirqs+0x2c4/0x970 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
  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Last potentially related work creation:
  kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
  __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
  __call_rcu_common kernel/rcu/tree.c:3106 [inline]
  call_rcu+0x167/0xa70 kernel/rcu/tree.c:3210
  refdst_drop include/net/dst.h:263 [inline]
  skb_dst_drop include/net/dst.h:275 [inline]
  nf_ct_frag6_queue net/ipv6/netfilter/nf_conntrack_reasm.c:306 [inline]
  nf_ct_frag6_gather+0xb9a/0x2080 net/ipv6/netfilter/nf_conntrack_reasm.c:485
  ipv6_defrag+0x2c8/0x3c0 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:67
  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]
  __ip6_local_out+0x6fa/0x800 net/ipv6/output_core.c:143
  ip6_local_out+0x26/0x70 net/ipv6/output_core.c:153
  ip6_send_skb+0x112/0x230 net/ipv6/ip6_output.c:1959
  rawv6_push_pending_frames+0x75c/0x9e0 net/ipv6/raw.c:588
  rawv6_sendmsg+0x19c7/0x23c0 net/ipv6/raw.c:926
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x1a6/0x270 net/socket.c:745
  sock_write_iter+0x2dd/0x400 net/socket.c:1160
 do_iter_readv_writev+0x60a/0x890

Fixes: 0625491493 ("ipv6: ip6_push_pending_frames() should increment IPSTATS_MIB_OUTDISCARDS")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20240820160859.3786976-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-21 17:35:49 -07:00
..
ila ila: block BH in ila_output() 2024-06-03 18:50:09 -07:00
netfilter netfilter: allow ipv6 fragments to arrive on different devices 2024-08-14 21:16:12 +02:00
addrconf_core.c ipv6: Ensure natural alignment of const ipv6 loopback and router addresses 2024-01-30 12:43:18 +01:00
addrconf.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
addrlabel.c ipv6: remove RTNL protection from ip6addrlbl_dump() 2024-04-08 11:01:05 +01:00
af_inet6.c ipsec-next-2024-07-13 2024-07-14 07:56:32 -07:00
ah6.c net: fill in MODULE_DESCRIPTION()s for ipv6 modules 2024-02-09 14:12:01 -08:00
anycast.c ipv6: anycast: use call_rcu_hurry() in aca_put() 2024-05-01 11:46:21 +01:00
calipso.c netlabel: remove impossible return value in netlbl_bitmap_walk 2024-02-28 19:37:34 -08:00
datagram.c ipv6: annotate data-races around np->ucast_oif 2023-12-11 10:59:17 +00:00
esp6_offload.c xfrm: Log input direction mismatch error in one place 2024-06-17 13:53:19 +02:00
esp6.c net: esp: cleanup esp_output_tail_tcp() in case of unsupported ESPINTCP 2024-05-23 08:46:03 +02:00
exthdrs_core.c ipv6: Fix out-of-bounds access in ipv6_find_tlv() 2023-05-24 08:43:39 +01:00
exthdrs_offload.c net: gso: add HBH extension header offload support 2024-01-05 08:11:49 -08:00
exthdrs.c net: ipv6: exthdrs: get rid of ipv6_skb_net() 2024-03-11 15:15:08 -07:00
fib6_notifier.c
fib6_rules.c ipv6: fib6_rules: avoid possible NULL dereference in fib6_rule_action() 2024-05-08 18:50:53 -07:00
fou6.c
icmp.c net: ipv{6,4}: Remove the now superfluous sentinel elements from ctl_table array 2024-05-03 13:29:42 +01:00
inet6_connection_sock.c net: implement lockless SO_PRIORITY 2023-10-01 19:09:54 +01:00
inet6_hashtables.c tcp: get rid of twsk_unique() 2024-05-09 20:25:55 -07:00
ioam6_iptunnel.c ipv6: ioam: block BH from ioam6_output() 2024-06-03 18:50:08 -07:00
ioam6.c ipv6/addrconf: annotate data-races around devconf fields (II) 2024-03-01 08:42:33 +00:00
ip6_checksum.c
ip6_fib.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-06-20 13:49:59 -07:00
ip6_flowlabel.c ipv6: move np->repflow to atomic flags 2023-09-15 10:33:48 +01:00
ip6_gre.c net: ip6_gre: Remove generic .ndo_get_stats64 2024-04-15 11:32:13 +01:00
ip6_icmp.c net: icmp: pass zeroed opts from icmp{,v6}_ndo_send before sending 2021-02-23 11:29:52 -08:00
ip6_input.c ipv6/addrconf: annotate data-races around devconf fields (II) 2024-03-01 08:42:33 +00:00
ip6_offload.c net: gro: initialize network_offset in network layer 2024-05-27 16:46:59 -07:00
ip6_offload.h
ip6_output.c ipv6: prevent UAF in ip6_send_skb() 2024-08-21 17:35:49 -07:00
ip6_tunnel.c ip6_tunnel: Fix broken GRO 2024-08-20 13:21:10 +02:00
ip6_udp_tunnel.c net: fill in MODULE_DESCRIPTION()s for ipv6 modules 2024-02-09 14:12:01 -08:00
ip6_vti.c net: annotate writes on dev->mtu from ndo_change_mtu() 2024-05-07 16:19:14 -07:00
ip6mr.c ipv6: introduce dst_rt6_info() helper 2024-04-29 13:32:01 +01:00
ipcomp6.c xfrm: ipcomp: add extack to ipcomp{4,6}_init_state 2022-09-29 07:18:00 +02:00
ipv6_sockglue.c net: use unrcu_pointer() helper 2024-06-06 11:52:52 +02:00
Kconfig ipv6: fix indentation of a config attribute 2023-08-16 10:03:08 +01:00
Makefile net/tcp: Introduce TCP_AO setsockopt()s 2023-10-27 10:35:44 +01:00
mcast_snoop.c net: bridge: mcast: fix broken length + header check for MRDv6 Adv. 2021-04-27 14:02:06 -07:00
mcast.c ipv6/addrconf: annotate data-races around devconf fields (II) 2024-03-01 08:42:33 +00:00
mip6.c net: fill in MODULE_DESCRIPTION()s for ipv6 modules 2024-02-09 14:12:01 -08:00
ndisc.c ipv6: fix ndisc_is_useropt() handling for PIO 2024-08-01 11:40:29 +02:00
netfilter.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-06-13 13:13:46 -07:00
output_core.c ipv6: annotate data-races around cnf.hop_limit 2024-03-01 08:42:31 +00:00
ping.c ipv6: introduce dst_rt6_info() helper 2024-04-29 13:32:01 +01:00
proc.c minmax: add a few more MIN_T/MAX_T users 2024-07-28 13:41:14 -07:00
protocol.c
raw.c net: raw: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
reassembly.c net: Rename mono_delivery_time to tstamp_type for scalabilty 2024-05-23 14:14:23 -07:00
route.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
rpl_iptunnel.c net: ipv6: rpl_iptunnel: block BH in rpl_output() and rpl_input() 2024-06-03 18:50:08 -07:00
rpl.c ipv6: rpl: Remove pskb(_may)?_pull() in ipv6_rpl_srh_rcv(). 2023-06-19 11:32:58 -07:00
seg6_hmac.c ipv6: sr: fix memleak in seg6_hmac_init_algo 2024-05-21 13:16:25 +02:00
seg6_iptunnel.c ipv6: sr: block BH in seg6_output_core() and seg6_input_core() 2024-06-03 18:50:08 -07:00
seg6_local.c seg6: Use nested-BH locking for seg6_bpf_srh_states. 2024-06-24 16:41:23 -07:00
seg6.c ipv6: sr: restruct ifdefines 2024-05-30 18:29:38 -07:00
sit.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
syncookies.c tcp: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
sysctl_net_ipv6.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
tcp_ao.c net/tcp: Wire up l3index to TCP-AO 2023-10-27 10:35:46 +01:00
tcp_ipv6.c tcp: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
tcpv6_offload.c net: gro: use cb instead of skb->network_header 2024-05-13 14:44:06 -07:00
tunnel6.c net: fill in MODULE_DESCRIPTION()s for ipv6 modules 2024-02-09 14:12:01 -08:00
udp_impl.h tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct(). 2022-10-12 17:50:37 -07:00
udp_offload.c net: gro: fix udp bad offset in socket lookup by adding {inner_}network_offset to napi_gro_cb 2024-05-02 11:02:48 +02:00
udp.c udp: Remove duplicate included header file trace/events/udp.h 2024-07-09 13:30:25 +02:00
udplite.c udplite: remove UDPLITE_BIT 2023-09-14 16:16:36 +02:00
xfrm6_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-05-09 10:01:01 -07:00
xfrm6_output.c ipv6: drop feature RTAX_FEATURE_ALLFRAG 2023-10-25 18:04:29 -07:00
xfrm6_policy.c ipsec-next-2024-07-13 2024-07-14 07:56:32 -07:00
xfrm6_protocol.c
xfrm6_state.c
xfrm6_tunnel.c ipsec-next-2024-03-06 2024-03-08 10:56:05 +00:00