linux/net/core
Eric Dumazet e195e9b5de net, neigh: clear whole pneigh_entry at alloc time
Commit 2c611ad97a ("net, neigh: Extend neigh->flags to 32 bit
to allow for extensions") enables a new KMSAM warning [1]

I think the bug is actually older, because the following intruction
only occurred if ndm->ndm_flags had NTF_PROXY set.

	pn->flags = ndm->ndm_flags;

Let's clear all pneigh_entry fields at alloc time.

[1]
BUG: KMSAN: uninit-value in pneigh_fill_info+0x986/0xb30 net/core/neighbour.c:2593
 pneigh_fill_info+0x986/0xb30 net/core/neighbour.c:2593
 pneigh_dump_table net/core/neighbour.c:2715 [inline]
 neigh_dump_info+0x1e3f/0x2c60 net/core/neighbour.c:2832
 netlink_dump+0xaca/0x16a0 net/netlink/af_netlink.c:2265
 __netlink_dump_start+0xd1c/0xee0 net/netlink/af_netlink.c:2370
 netlink_dump_start include/linux/netlink.h:254 [inline]
 rtnetlink_rcv_msg+0x181b/0x18c0 net/core/rtnetlink.c:5534
 netlink_rcv_skb+0x447/0x800 net/netlink/af_netlink.c:2491
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5589
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x1095/0x1360 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x16f3/0x1870 net/netlink/af_netlink.c:1916
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 sock_write_iter+0x594/0x690 net/socket.c:1057
 call_write_iter include/linux/fs.h:2162 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x1318/0x2030 fs/read_write.c:590
 ksys_write+0x28c/0x520 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0xdb/0x120 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:524 [inline]
 slab_alloc_node mm/slub.c:3251 [inline]
 slab_alloc mm/slub.c:3259 [inline]
 __kmalloc+0xc3c/0x12d0 mm/slub.c:4437
 kmalloc include/linux/slab.h:595 [inline]
 pneigh_lookup+0x60f/0xd70 net/core/neighbour.c:766
 arp_req_set_public net/ipv4/arp.c:1016 [inline]
 arp_req_set+0x430/0x10a0 net/ipv4/arp.c:1032
 arp_ioctl+0x8d4/0xb60 net/ipv4/arp.c:1232
 inet_ioctl+0x4ef/0x820 net/ipv4/af_inet.c:947
 sock_do_ioctl net/socket.c:1118 [inline]
 sock_ioctl+0xa3f/0x13e0 net/socket.c:1235
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0x2df/0x4a0 fs/ioctl.c:860
 __x64_sys_ioctl+0xd8/0x110 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

CPU: 1 PID: 20001 Comm: syz-executor.0 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 62dd93181a ("[IPV6] NDISC: Set per-entry is_router flag in Proxy NA.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20211206165329.1049835-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-08 17:41:44 -08:00
..
bpf_sk_storage.c net: in_irq() cleanup 2021-08-13 14:09:19 -07:00
datagram.c net: avoid double accounting for pure zerocopy skbs 2021-11-03 11:19:49 +00:00
datagram.h
dev_addr_lists.c net: dev_addr_list: handle first address in __hw_addr_add_ex 2021-09-30 13:29:09 +01:00
dev_ioctl.c ethtool: push the rtnl_lock into dev_ethtool() 2021-11-01 13:26:07 +00:00
dev.c net: annotate data-races on txq->xmit_lock_owner 2021-12-01 19:14:26 -08:00
devlink.c devlink: fix netns refcount leak in devlink_nl_cmd_reload() 2021-12-06 16:56:32 -08:00
drop_monitor.c net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
dst_cache.c wireguard: device: reset peer src endpoint when netns exits 2021-11-29 19:50:45 -08:00
dst.c net: Remove redundant if statements 2021-08-05 13:27:50 +01:00
failover.c
fib_notifier.c
fib_rules.c ipv6: fix memory leak in fib6_rule_suppress 2021-11-29 14:43:35 +00:00
filter.c bpf: Forbid bpf_ktime_get_coarse_ns and bpf_timer_* in tracing progs 2021-11-15 20:35:58 -08:00
flow_dissector.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-11-01 20:05:14 -07:00
flow_offload.c net: Fix offloading indirect devices dependency on qdisc order creation 2021-08-19 13:19:30 +01:00
gen_estimator.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
gen_stats.c net: stats: Read the statistics in ___gnet_stats_copy_basic() instead of adding. 2021-10-21 12:47:56 +01:00
gro_cells.c gro_cells: reduce number of synchronize_net() calls 2020-11-25 11:28:12 -08:00
hwbm.c
link_watch.c net: linkwatch: fix failure to restore device state across suspend/resume 2021-08-11 14:43:16 -07:00
lwt_bpf.c lwt_bpf: Replace preempt_disable() with migrate_disable() 2020-12-07 11:53:40 -08:00
lwtunnel.c netfilter: add netfilter hooks to SRv6 data plane 2021-08-30 01:51:36 +02:00
Makefile of: net: move of_net under net/ 2021-10-07 13:39:51 +01:00
neighbour.c net, neigh: clear whole pneigh_entry at alloc time 2021-12-08 17:41:44 -08:00
net_namespace.c net: net_namespace: Fix undefined member in key_remove_domain() 2021-09-19 12:43:04 +01:00
net-procfs.c Revert "net: procfs: add seq_puts() statement for dev_mcast" 2021-10-13 17:24:38 -07:00
net-sysfs.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-10-28 10:43:58 -07:00
net-sysfs.h
net-traces.c tcp: add tracepoint for checksum errors 2021-05-14 15:26:03 -07:00
netclassid_cgroup.c bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode 2021-09-13 16:35:58 -07:00
netevent.c net: core: Correct function name netevent_unregister_notifier() in the kerneldoc 2021-03-28 17:56:56 -07:00
netpoll.c asm-generic/unaligned: Unify asm/unaligned.h around struct helper 2021-07-02 12:43:40 -07:00
netprio_cgroup.c bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode 2021-09-13 16:35:58 -07:00
of_net.c of: net: add a helper for loading netdev->dev_addr 2021-10-07 13:39:51 +01:00
page_pool.c page_pool: Revert "page_pool: disable dma mapping support..." 2021-11-18 11:29:40 +00:00
pktgen.c pktgen: remove unused variable 2021-09-03 11:48:28 +01:00
ptp_classifier.c bpf: Refactor BPF_PROG_RUN into a function 2021-08-17 00:45:07 +02:00
request_sock.c
rtnetlink.c net: rtnetlink: use __dev_addr_set() 2021-10-24 13:59:44 +01:00
scm.c memcg: enable accounting for scm_fp_list objects 2021-07-20 06:00:38 -07:00
secure_seq.c
selftests.c net: core: constify mac addrs in selftests 2021-10-24 13:59:44 +01:00
skbuff.c net: avoid double accounting for pure zerocopy skbs 2021-11-03 11:19:49 +00:00
skmsg.c bpf, sockmap: Re-evaluate proto ops when psock is removed from sockmap 2021-11-20 00:56:24 +01:00
sock_destructor.h skb_expand_head() adjust skb->truesize incorrectly 2021-10-22 12:35:51 -07:00
sock_diag.c bpf, net: Rework cookie generator as per-cpu one 2020-09-30 11:50:35 -07:00
sock_map.c bpf, sockmap: Re-evaluate proto ops when psock is removed from sockmap 2021-11-20 00:56:24 +01:00
sock_reuseport.c tcp: Add stats for socket migration. 2021-06-23 12:56:08 -07:00
sock.c sock: fix /proc/net/sockstat underflow in sk_clone_lock() 2021-11-15 14:27:39 +00:00
stream.c net: stream: don't purge sk_error_queue in sk_stream_kill_queues() 2021-10-16 09:06:09 +01:00
sysctl_net_core.c bpf: Prevent increasing bpf_jit_limit above max 2021-10-22 17:23:53 -07:00
timestamping.c
tso.c
utils.c
xdp.c xdp: Remove redundant warning 2021-10-27 18:13:57 -07:00