linux/net
Eric Dumazet dc56ad7028 af_unix: fix potential NULL deref in unix_dgram_connect()
syzbot was able to trigger NULL deref in unix_dgram_connect() [1]

This happens in

	if (unix_peer(sk))
		sk->sk_state = other->sk_state = TCP_ESTABLISHED; // crash because @other is NULL

Because locks have been dropped, unix_peer() might be non NULL,
while @other is NULL (AF_UNSPEC case)

We need to move code around, so that we no longer access
unix_peer() and sk_state while locks have been released.

[1]
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 10341 Comm: syz-executor239 Not tainted 5.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:unix_dgram_connect+0x32a/0xc60 net/unix/af_unix.c:1226
Code: 00 00 45 31 ed 49 83 bc 24 f8 05 00 00 00 74 69 e8 eb 5b a6 f9 48 8d 7d 12 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 e0 07 00 00
RSP: 0018:ffffc9000a89fcd8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffffffff87cf4ef5 RDI: 0000000000000012
RBP: 0000000000000000 R08: 0000000000000000 R09: ffff88802e1917c3
R10: ffffffff87cf4eba R11: 0000000000000001 R12: ffff88802e191740
R13: 0000000000000000 R14: ffff88802e191d38 R15: ffff88802e1917c0
FS:  00007f3eb0052700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004787d0 CR3: 0000000029c0a000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __sys_connect_file+0x155/0x1a0 net/socket.c:1890
 __sys_connect+0x161/0x190 net/socket.c:1907
 __do_sys_connect net/socket.c:1917 [inline]
 __se_sys_connect net/socket.c:1914 [inline]
 __x64_sys_connect+0x6f/0xb0 net/socket.c:1914
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x446a89
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 15 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3eb0052208 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00000000004cc4d8 RCX: 0000000000446a89
RDX: 000000000000006e RSI: 0000000020000180 RDI: 0000000000000003
RBP: 00000000004cc4d0 R08: 00007f3eb0052700 R09: 0000000000000000
R10: 00007f3eb0052700 R11: 0000000000000246 R12: 00000000004cc4dc
R13: 00007ffd791e79cf R14: 00007f3eb0052300 R15: 0000000000022000
Modules linked in:
---[ end trace 4eb809357514968c ]---
RIP: 0010:unix_dgram_connect+0x32a/0xc60 net/unix/af_unix.c:1226
Code: 00 00 45 31 ed 49 83 bc 24 f8 05 00 00 00 74 69 e8 eb 5b a6 f9 48 8d 7d 12 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 e0 07 00 00
RSP: 0018:ffffc9000a89fcd8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffffffff87cf4ef5 RDI: 0000000000000012
RBP: 0000000000000000 R08: 0000000000000000 R09: ffff88802e1917c3
R10: ffffffff87cf4eba R11: 0000000000000001 R12: ffff88802e191740
R13: 0000000000000000 R14: ffff88802e191d38 R15: ffff88802e1917c0
FS:  00007f3eb0052700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd791fe960 CR3: 0000000029c0a000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fixes: 83301b5367 ("af_unix: Set TCP_ESTABLISHED for datagram sockets too")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Cong Wang <cong.wang@bytedance.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-31 11:31:52 +01:00
..
6lowpan 6lowpan: iphc: Fix an off-by-one check of array index 2021-07-22 16:19:03 +02:00
9p 9p/trans_virtio: Fix spelling mistakes 2021-06-02 14:01:55 -07:00
802 net: 802: remove dead leftover after ipx driver removal 2021-08-13 16:30:35 -07:00
8021q dev_ioctl: split out ndo_eth_ioctl 2021-07-27 20:11:45 +01:00
appletalk net: socket: rework compat_ifreq_ioctl() 2021-07-23 14:20:25 +01:00
atm atm: Use list_for_each_entry() to simplify code in resources.c 2021-06-10 14:08:09 -07:00
ax25 ax25: use skb_expand_head 2021-08-03 11:21:39 +01:00
batman-adv batman-adv: bcast: remove remaining skb-copy calls 2021-08-18 18:39:00 +02:00
bluetooth bluetooth-next pull request for net-next: 2021-08-20 12:16:05 +01:00
bpf bpf: Refactor BPF_PROG_RUN into a function 2021-08-17 00:45:07 +02:00
bpfilter bpfilter: Specify the log level for the kmsg message 2021-06-25 13:13:50 +02:00
bridge net: bridge: use mld2r_ngrec instead of icmpv6_dataun 2021-08-31 11:29:23 +01:00
caif net: fix uninit-value in caif_seqpkt_sendmsg 2021-07-15 11:08:33 -07:00
can net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
ceph Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
core Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-08-30 16:42:47 -07:00
dcb net: dcb: Return the correct errno code 2021-06-01 17:01:33 -07:00
dccp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-13 06:41:22 -07:00
decnet net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
dns_resolver
dsa net: dsa: tag_sja1105: stop asking the sja1105 driver in sja1105_xmit_tpid 2021-08-25 11:14:34 +01:00
ethernet move netdev_boot_setup into Space.c 2021-08-03 13:05:26 +01:00
ethtool ethtool: extend coalesce setting uAPI with CQE mode 2021-08-24 07:38:29 -07:00
hsr net: hsr: don't check sequence number if tag removal is offloaded 2021-06-16 12:13:01 -07:00
ieee802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-13 06:41:22 -07:00
ife
ipv4 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-08-30 16:42:47 -07:00
ipv6 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-08-30 16:42:47 -07:00
iucv net/iucv: Replace deprecated CPU-hotplug functions. 2021-08-09 10:13:32 +01:00
kcm net: sock: introduce sk_error_report 2021-06-29 11:28:21 -07:00
key net: Remove unnecessary variables 2021-05-26 07:03:39 +02:00
l2tp l2tp: Fix spelling mistakes 2021-06-07 14:08:30 -07:00
l3mdev
lapb net: lapb: Use list_for_each_entry() to simplify code in lapb_iface.c 2021-06-08 16:31:25 -07:00
llc net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
mac80211 mac80211: parse transmit power envelope element 2021-08-26 10:18:56 +02:00
mac802154
mctp mctp: Specify route types, require rtm_type in RTM_*ROUTE messages 2021-08-11 16:01:17 -07:00
mpls mpls: defer ttl decrement in mpls_forward() 2021-07-23 17:17:56 +01:00
mptcp mptcp: make the locking tx schema more readable 2021-08-27 09:45:07 +01:00
ncsi net/ncsi: add dummy response handler for Intel boards 2021-07-08 14:16:39 -07:00
netfilter Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-08-30 16:42:47 -07:00
netlabel net: fix NULL pointer reference in cipso_v4_doi_free 2021-08-30 12:23:18 +01:00
netlink net: netlink: Remove unused function 2021-07-30 18:35:47 +02:00
netrom net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
nfc net: in_irq() cleanup 2021-08-13 14:09:19 -07:00
nsh
openvswitch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-19 18:09:18 -07:00
packet net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
phonet net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
psample
qrtr net: qrtr: make checks in qrtr_endpoint_post() stricter 2021-08-30 12:26:57 +01:00
rds net/rds: dma_map_sg is entitled to merge entries 2021-08-18 15:35:50 -07:00
rfkill
rose
rxrpc net: RxRPC: make dependent Kconfig symbols be shown indented 2021-08-18 10:12:11 +01:00
sched net: sched: Fix qdisc_rate_table refcount leak when get tcf_block failed 2021-08-30 20:29:03 -07:00
sctp sctp: move the active_key update after sh_keys is added 2021-08-03 11:43:43 +01:00
smc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-13 06:41:22 -07:00
strparser net: sock: introduce sk_error_report 2021-06-29 11:28:21 -07:00
sunrpc SUNRPC: Fix XPT_BUSY flag leakage in svc_handle_xprt()... 2021-08-25 16:58:09 -04:00
switchdev net: make switchdev_bridge_port_{,unoffload} loosely coupled with the bridge 2021-08-04 12:35:07 +01:00
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-19 18:09:18 -07:00
tls Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-06-29 15:45:27 -07:00
unix af_unix: fix potential NULL deref in unix_dgram_connect() 2021-08-31 11:31:52 +01:00
vmw_vsock vsock/virtio: avoid potential deadlock when vsock device remove 2021-08-12 10:57:27 -07:00
wireless cfg80211: use wiphy DFS domain if it is self-managed 2021-08-26 11:04:55 +02:00
x25 net: x25: Use list_for_each_entry() to simplify code in x25_route.c 2021-06-10 14:08:09 -07:00
xdp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-06-29 15:45:27 -07:00
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ 2021-08-27 11:16:29 +01:00
compat.c net: Return the correct errno code 2021-06-03 15:13:56 -07:00
devres.c net: devres: Correct a grammatical error 2021-06-11 12:55:28 -07:00
Kconfig mctp: Add MCTP base 2021-07-29 15:06:49 +01:00
Makefile mctp: Add MCTP base 2021-07-29 15:06:49 +01:00
socket.c mctp: Add MCTP base 2021-07-29 15:06:49 +01:00
sysctl_net.c