linux/net
Duoming Zhou 4e0f718daf ax25: improve the incomplete fix to avoid UAF and NPD bugs
The previous commit 1ade48d0c2 ("ax25: NPD bug when detaching
AX25 device") introduce lock_sock() into ax25_kill_by_device to
prevent NPD bug. But the concurrency NPD or UAF bug will occur,
when lock_sock() or release_sock() dereferences the ax25_cb->sock.

The NULL pointer dereference bug can be shown as below:

ax25_kill_by_device()        | ax25_release()
                             |   ax25_destroy_socket()
                             |     ax25_cb_del()
  ...                        |     ...
                             |     ax25->sk=NULL;
  lock_sock(s->sk); //(1)    |
  s->ax25_dev = NULL;        |     ...
  release_sock(s->sk); //(2) |
  ...                        |

The root cause is that the sock is set to null before dereference
site (1) or (2). Therefore, this patch extracts the ax25_cb->sock
in advance, and uses ax25_list_lock to protect it, which can synchronize
with ax25_cb_del() and ensure the value of sock is not null before
dereference sites.

The concurrency UAF bug can be shown as below:

ax25_kill_by_device()        | ax25_release()
                             |   ax25_destroy_socket()
  ...                        |   ...
                             |   sock_put(sk); //FREE
  lock_sock(s->sk); //(1)    |
  s->ax25_dev = NULL;        |   ...
  release_sock(s->sk); //(2) |
  ...                        |

The root cause is that the sock is released before dereference
site (1) or (2). Therefore, this patch uses sock_hold() to increase
the refcount of sock and uses ax25_list_lock to protect it, which
can synchronize with ax25_cb_del() in ax25_destroy_socket() and
ensure the sock wil not be released before dereference sites.

Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-28 14:56:47 +00:00
..
6lowpan 6lowpan: iphc: Fix an off-by-one check of array index 2021-07-22 16:19:03 +02:00
9p virtio,vdpa,qemu_fw_cfg: features, cleanups, fixes 2022-01-18 10:05:48 +02:00
802 net: 802: Use memset_startat() to clear struct fields 2021-11-19 11:23:23 +00:00
8021q vlan: add net device refcount tracker 2021-12-07 20:44:58 -08:00
appletalk net: socket: rework compat_ifreq_ioctl() 2021-07-23 14:20:25 +01:00
atm proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
ax25 ax25: improve the incomplete fix to avoid UAF and NPD bugs 2022-01-28 14:56:47 +00:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-05 14:36:10 -08:00
bluetooth proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
bpf bpf: Add dummy BPF STRUCT_OPS for test purpose 2021-11-01 14:10:00 -07:00
bpfilter
bridge Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2022-01-27 18:53:02 -08:00
caif Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-31 14:35:40 +00:00
can proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
ceph The highlight is the new mount "device" string syntax implemented 2022-01-20 13:46:20 +02:00
core Networking fixes for 5.17-rc2, including fixes from netfilter and can. 2022-01-27 20:58:39 +02:00
dcb
dccp dccp: Inline dccp_listen_start(). 2021-11-23 20:16:22 -08:00
decnet Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-31 14:35:40 +00:00
dns_resolver
dsa net: dsa: setup master before ports 2022-01-06 11:59:10 +00:00
ethernet gro: remove rcu_read_lock/rcu_read_unlock from gro_complete handlers 2021-11-24 17:21:42 -08:00
ethtool ethtool: use phydev variable 2022-01-06 12:33:35 +00:00
hsr net: Write lock dev_base_lock without disabling bottom halves. 2021-11-29 12:12:36 +00:00
ieee802154 net: drop nopreempt requirement on sock_prot_inuse_add() 2021-11-16 13:20:45 +00:00
ife
ipv4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2022-01-27 18:53:02 -08:00
ipv6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2022-01-27 18:53:02 -08:00
iucv net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
kcm net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
key
l2tp l2tp: add netns refcount tracker to l2tp_dfs_seq_data 2021-12-10 06:38:27 -08:00
l3mdev
lapb
llc sock: Use sock_owned_by_user_nocheck() instead of sk_lock.owned. 2021-12-10 19:43:00 -08:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-05 14:36:10 -08:00
mac802154 mac802154: use dev_addr_set() - manual 2021-10-20 14:27:40 +01:00
mctp mctp: test: zero out sockaddr 2022-01-11 20:26:36 -08:00
mpls Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-12-02 11:44:56 -08:00
mptcp mptcp: Use struct_group() to avoid cross-field memset() 2022-01-21 19:26:03 -08:00
ncsi all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate 2022-01-15 08:47:31 -08:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2022-01-27 18:53:02 -08:00
netlabel lsm: security_task_getsecid_subj() -> security_current_getsecid_subj() 2021-11-22 17:52:47 -05:00
netlink net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
netrom netrom: fix api breakage in nr_setsockopt() 2022-01-07 14:11:05 +00:00
nfc Networking fixes for 5.17-rc1, including fixes from netfilter, bpf. 2022-01-20 10:57:05 +02:00
nsh
openvswitch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-09 17:00:17 -08:00
packet net: fix information leakage in /proc/net/ptype 2022-01-20 10:12:53 +00:00
phonet phonet/pep: refuse to enable an unbound pipe 2021-12-20 11:49:51 +00:00
psample
qrtr bus: mhi: core: Add an API for auto queueing buffers for DL channel 2021-12-17 17:17:14 +01:00
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-12-16 16:13:19 -08:00
rfkill rfkill: allow to get the software rfkill state 2021-12-20 11:02:38 +01:00
rose net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
rxrpc rxrpc: Adjust retransmission backoff 2022-01-22 02:03:24 +00:00
sched sch_htb: Fail on unsupported parameters when offload is requested 2022-01-25 20:00:02 -08:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-05 14:36:10 -08:00
smc net/smc: Transitional solution for clcsock race issue 2022-01-24 12:06:08 +00:00
strparser bpf: sockmap, strparser, and tls are reusing qdisc_skb_cb and colliding 2021-11-09 01:05:28 +01:00
sunrpc NFS Client Updates for Linux 5.17 2022-01-25 20:16:03 +02:00
switchdev net: switchdev: add net device refcount tracker 2021-12-07 20:44:58 -08:00
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-05 14:36:10 -08:00
tls net/tls: Fix another skb memory leak when running kTLS traffic 2022-01-17 13:07:47 +00:00
unix af_unix: annote lockless accesses to unix_tot_inflight & gc_in_progress 2022-01-14 18:31:37 -08:00
vmw_vsock virtio,vdpa,qemu_fw_cfg: features, cleanups, fixes 2022-01-18 10:05:48 +02:00
wireless Kbuild updates for v5.17 2022-01-19 11:15:19 +02:00
x25 net: x25: drop harmless check of !more 2021-12-09 18:35:11 -08:00
xdp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-05 14:36:10 -08:00
xfrm xfrm: Don't accidentally set RTO_ONLINK in decode_session4() 2022-01-11 20:36:08 -08:00
compat.c
devres.c
Kconfig net: kunit: add a test for dev_addr_lists 2021-11-20 12:25:57 +00:00
Kconfig.debug net: add networking namespace refcount tracker 2021-12-10 06:38:26 -08:00
Makefile mctp: Add MCTP base 2021-07-29 15:06:49 +01:00
socket.c net: fix SOF_TIMESTAMPING_BIND_PHC to work with multiple sockets 2022-01-06 12:18:08 +00:00
sysctl_net.c sections: move and rename core_kernel_data() to is_kernel_core_data() 2021-11-09 10:02:50 -08:00