linux-uconsole/net
Eric Dumazet 3d55b19574 netlink: reset network and mac headers in netlink_dump()
[ Upstream commit 99c07327ae ]

netlink_dump() is allocating an skb, reserves space in it
but forgets to reset network header.

This allows a BPF program, invoked later from sk_filter()
to access uninitialized kernel memory from the reserved
space.

Theorically mac header reset could be omitted, because
it is set to a special initial value.
bpf_internal_load_pointer_neg_helper calls skb_mac_header()
without checking skb_mac_header_was_set().
Relying on skb->len not being too big seems fragile.
We also could add a sanity check in bpf_internal_load_pointer_neg_helper()
to avoid surprises in the future.

syzbot report was:

BUG: KMSAN: uninit-value in ___bpf_prog_run+0xa22b/0xb420 kernel/bpf/core.c:1637
 ___bpf_prog_run+0xa22b/0xb420 kernel/bpf/core.c:1637
 __bpf_prog_run32+0x121/0x180 kernel/bpf/core.c:1796
 bpf_dispatcher_nop_func include/linux/bpf.h:784 [inline]
 __bpf_prog_run include/linux/filter.h:626 [inline]
 bpf_prog_run include/linux/filter.h:633 [inline]
 __bpf_prog_run_save_cb+0x168/0x580 include/linux/filter.h:756
 bpf_prog_run_save_cb include/linux/filter.h:770 [inline]
 sk_filter_trim_cap+0x3bc/0x8c0 net/core/filter.c:150
 sk_filter include/linux/filter.h:905 [inline]
 netlink_dump+0xe0c/0x16c0 net/netlink/af_netlink.c:2276
 netlink_recvmsg+0x1129/0x1c80 net/netlink/af_netlink.c:2002
 sock_recvmsg_nosec net/socket.c:948 [inline]
 sock_recvmsg net/socket.c:966 [inline]
 sock_read_iter+0x5a9/0x630 net/socket.c:1039
 do_iter_readv_writev+0xa7f/0xc70
 do_iter_read+0x52c/0x14c0 fs/read_write.c:786
 vfs_readv fs/read_write.c:906 [inline]
 do_readv+0x432/0x800 fs/read_write.c:943
 __do_sys_readv fs/read_write.c:1034 [inline]
 __se_sys_readv fs/read_write.c:1031 [inline]
 __x64_sys_readv+0xe5/0x120 fs/read_write.c:1031
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was stored to memory at:
 ___bpf_prog_run+0x96c/0xb420 kernel/bpf/core.c:1558
 __bpf_prog_run32+0x121/0x180 kernel/bpf/core.c:1796
 bpf_dispatcher_nop_func include/linux/bpf.h:784 [inline]
 __bpf_prog_run include/linux/filter.h:626 [inline]
 bpf_prog_run include/linux/filter.h:633 [inline]
 __bpf_prog_run_save_cb+0x168/0x580 include/linux/filter.h:756
 bpf_prog_run_save_cb include/linux/filter.h:770 [inline]
 sk_filter_trim_cap+0x3bc/0x8c0 net/core/filter.c:150
 sk_filter include/linux/filter.h:905 [inline]
 netlink_dump+0xe0c/0x16c0 net/netlink/af_netlink.c:2276
 netlink_recvmsg+0x1129/0x1c80 net/netlink/af_netlink.c:2002
 sock_recvmsg_nosec net/socket.c:948 [inline]
 sock_recvmsg net/socket.c:966 [inline]
 sock_read_iter+0x5a9/0x630 net/socket.c:1039
 do_iter_readv_writev+0xa7f/0xc70
 do_iter_read+0x52c/0x14c0 fs/read_write.c:786
 vfs_readv fs/read_write.c:906 [inline]
 do_readv+0x432/0x800 fs/read_write.c:943
 __do_sys_readv fs/read_write.c:1034 [inline]
 __se_sys_readv fs/read_write.c:1031 [inline]
 __x64_sys_readv+0xe5/0x120 fs/read_write.c:1031
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:737 [inline]
 slab_alloc_node mm/slub.c:3244 [inline]
 __kmalloc_node_track_caller+0xde3/0x14f0 mm/slub.c:4972
 kmalloc_reserve net/core/skbuff.c:354 [inline]
 __alloc_skb+0x545/0xf90 net/core/skbuff.c:426
 alloc_skb include/linux/skbuff.h:1158 [inline]
 netlink_dump+0x30f/0x16c0 net/netlink/af_netlink.c:2242
 netlink_recvmsg+0x1129/0x1c80 net/netlink/af_netlink.c:2002
 sock_recvmsg_nosec net/socket.c:948 [inline]
 sock_recvmsg net/socket.c:966 [inline]
 sock_read_iter+0x5a9/0x630 net/socket.c:1039
 do_iter_readv_writev+0xa7f/0xc70
 do_iter_read+0x52c/0x14c0 fs/read_write.c:786
 vfs_readv fs/read_write.c:906 [inline]
 do_readv+0x432/0x800 fs/read_write.c:943
 __do_sys_readv fs/read_write.c:1034 [inline]
 __se_sys_readv fs/read_write.c:1031 [inline]
 __x64_sys_readv+0xe5/0x120 fs/read_write.c:1031
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x44/0xae

CPU: 0 PID: 3470 Comm: syz-executor751 Not tainted 5.17.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: db65a3aaf2 ("netlink: Trim skb to alloc size to avoid MSG_TRUNC")
Fixes: 9063e21fb0 ("netlink: autosize skb lengthes")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220415181442.551228-1-eric.dumazet@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-27 13:53:51 +02:00
..
6lowpan 6lowpan: iphc: Fix an off-by-one check of array index 2021-09-15 09:50:34 +02:00
9p xen/9p: use alloc/free_pages_exact() 2022-03-11 12:11:54 +01:00
802 net/802/garp: fix memleak in garp_request_join() 2021-07-31 08:16:11 +02:00
8021q net: vlan: fix underflow for the real_dev refcnt 2021-12-01 09:19:08 +01:00
appletalk appletalk: Fix skb allocation size in loopback case 2021-04-07 15:00:08 +02:00
atm net: atm: fix update of position index in lec_seq_next 2020-10-31 12:26:30 -07:00
ax25 ax25: Fix UAF bugs in ax25 timers 2022-04-20 09:23:32 +02:00
batman-adv ipv6: make mc_forwarding atomic 2022-04-13 21:00:56 +02:00
bluetooth Bluetooth: Fix use after free in hci_send_acl 2022-04-13 21:01:00 +02:00
bpf bpf, test, cgroup: Use sk_{alloc,free} for test cases 2021-10-27 09:56:56 +02:00
bpfilter bpfilter: Specify the log level for the kmsg message 2021-07-14 16:56:29 +02:00
bridge net: bridge: vlan: fix memory leak in __allowed_ingress 2022-02-01 17:25:48 +01:00
caif net-caif: avoid user-triggerable WARN_ON(1) 2021-09-22 12:27:56 +02:00
can can: isotp: set default value for N_As to 50 micro seconds 2022-04-13 21:01:00 +02:00
ceph libceph: clear con->out_msg on Policy::stateful_server faults 2020-10-12 15:29:27 +02:00
core net/sched: flower: fix parsing of ethertype following VLAN header 2022-04-20 09:23:11 +02:00
dcb net: dcb: disable softirqs in dcbnl_flush_dev() 2022-03-08 19:09:37 +01:00
dccp tcp: switch orphan_count to bare per-cpu counters 2021-11-18 14:04:08 +01:00
decnet net: decnet: Fix sleeping inside in af_decnet 2021-07-28 14:35:38 +02:00
dns_resolver
dsa net: dsa: Add missing of_node_put() in dsa_port_parse_of 2022-03-23 09:13:28 +01:00
ethernet
ethtool ethtool: do not perform operations on net devices being unregistered 2021-12-17 10:14:41 +01:00
hsr net: hsr: fix mac_len checks 2021-06-03 09:00:50 +02:00
ieee802154 net: ieee802154: Return meaningful error codes from the netlink helpers 2022-02-08 18:30:37 +01:00
ife
ipv4 esp: limit skb_page_frag_refill use to a single page 2022-04-27 13:53:48 +02:00
ipv6 ipv6: make ip6_rt_gc_expire an atomic_t 2022-04-27 13:53:51 +02:00
iucv net/af_iucv: remove WARN_ONCE on malformed RX packets 2021-03-07 12:34:05 +01:00
kcm
key af_key: add __GFP_ZERO flag for compose_sadb_supported in function pfkey_register 2022-04-08 14:39:48 +02:00
l2tp net/l2tp: Fix reference count leak in l2tp_udp_recv_core 2021-09-22 12:27:56 +02:00
l3mdev l3mdev: l3mdev_master_upper_ifindex_by_index_rcu should be using netdev_master_upper_dev_get_rcu 2022-04-27 13:53:50 +02:00
lapb net: lapb: Copy the skb before sending a packet 2021-02-10 09:29:14 +01:00
llc llc: only change llc->dev when bind() succeeds 2022-03-28 09:57:10 +02:00
mac80211 mac80211: fix potential double free on mesh join 2022-03-28 09:57:10 +02:00
mac802154 net: mac802154: Fix general protection fault 2021-04-14 08:42:13 +02:00
mpls net: mpls: Fix notifications when deleting a device 2021-12-08 09:03:23 +01:00
mptcp mptcp: clear 'kern' flag from fallback sockets 2021-12-22 09:30:54 +01:00
ncsi net/ncsi: check for error return from call to nla_put_u32 2022-01-05 12:40:32 +01:00
netfilter netfilter: nf_conntrack_tcp: preserve liberal flag in tcp options 2022-04-08 14:40:28 +02:00
netlabel netlabel: fix out-of-bounds memory accesses 2022-04-13 21:01:00 +02:00
netlink netlink: reset network and mac headers in netlink_dump() 2022-04-27 13:53:51 +02:00
netrom netrom: fix api breakage in nr_setsockopt() 2022-01-27 10:54:03 +01:00
nfc nfc: nci: add flush_workqueue to prevent uaf 2022-04-20 09:23:18 +02:00
nsh
openvswitch net: openvswitch: fix leak of nested actions 2022-04-13 21:01:06 +02:00
packet net/packet: fix packet_sock xmit return value checking 2022-04-27 13:53:50 +02:00
phonet phonet: refcount leak in pep_sock_accep 2022-01-11 15:25:01 +01:00
psample net: psample: Fix netlink skb length with tunnel info 2021-03-07 12:34:07 +01:00
qrtr net: qrtr: fix another OOB Read in qrtr_endpoint_post 2021-09-03 10:09:21 +02:00
rds rds: memory leak in __rds_conn_create() 2021-12-22 09:30:54 +01:00
rfkill rfkill: Fix use-after-free in rfkill_resume() 2020-11-12 09:18:06 +01:00
rose rose: Fix Null pointer dereference in rose_send_frame() 2020-11-20 10:04:58 -08:00
rxrpc rxrpc: Restore removed timer deletion 2022-04-27 13:53:49 +02:00
sched net/sched: cls_u32: fix possible leak in u32_init_knode() 2022-04-27 13:53:50 +02:00
sctp sctp: Initialize daddr on peeled off socket 2022-04-20 09:23:17 +02:00
smc net/smc: Fix sock leak when release after smc_shutdown() 2022-04-27 13:53:49 +02:00
strparser bpf: sockmap, strparser, and tls are reusing qdisc_skb_cb and colliding 2021-11-18 14:04:27 +01:00
sunrpc SUNRPC: svc_tcp_sendmsg() should handle errors from xdr_alloc_bvec() 2022-04-13 21:01:07 +02:00
switchdev net: switchdev: don't set port_obj_info->handled true when -EOPNOTSUPP 2021-02-07 15:37:12 +01:00
tipc tipc: fix the timer expires after interval 100ms 2022-04-08 14:40:23 +02:00
tls net/tls: fix slab-out-of-bounds bug in decrypt_internal 2022-04-13 21:01:04 +02:00
unix af_unix: annote lockless accesses to unix_tot_inflight & gc_in_progress 2022-01-27 10:54:31 +01:00
vmw_vsock vsock: each transport cycles only on its own sockets 2022-03-23 09:13:27 +01:00
wimax genetlink: move to smaller ops wherever possible 2020-10-02 19:11:11 -07:00
wireless nl80211: correctly check NL80211_ATTR_REG_ALPHA2 size 2022-04-20 09:23:28 +02:00
x25 net/x25: Fix null-ptr-deref caused by x25_disconnect 2022-04-08 14:40:30 +02:00
xdp Revert "xsk: Do not sleep in poll() when need_wakeup set" 2021-12-22 09:30:59 +01:00
xfrm xfrm: fix tunnel model fragmentation behavior 2022-04-08 14:39:47 +02:00
compat.c net: Return the correct errno code 2021-06-18 10:00:06 +02:00
devres.c
Kconfig
Makefile
socket.c ethtool: improve compat ioctl handling 2021-09-18 13:40:21 +02:00
sysctl_net.c