linux/net/netfilter/ipvs
YueHaibing 719c7d563c ipvs: Fix use-after-free in ip_vs_in
BUG: KASAN: use-after-free in ip_vs_in.part.29+0xe8/0xd20 [ip_vs]
Read of size 4 at addr ffff8881e9b26e2c by task sshd/5603

CPU: 0 PID: 5603 Comm: sshd Not tainted 4.19.39+ #30
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Call Trace:
 dump_stack+0x71/0xab
 print_address_description+0x6a/0x270
 kasan_report+0x179/0x2c0
 ip_vs_in.part.29+0xe8/0xd20 [ip_vs]
 ip_vs_in+0xd8/0x170 [ip_vs]
 nf_hook_slow+0x5f/0xe0
 __ip_local_out+0x1d5/0x250
 ip_local_out+0x19/0x60
 __tcp_transmit_skb+0xba1/0x14f0
 tcp_write_xmit+0x41f/0x1ed0
 ? _copy_from_iter_full+0xca/0x340
 __tcp_push_pending_frames+0x52/0x140
 tcp_sendmsg_locked+0x787/0x1600
 ? tcp_sendpage+0x60/0x60
 ? inet_sk_set_state+0xb0/0xb0
 tcp_sendmsg+0x27/0x40
 sock_sendmsg+0x6d/0x80
 sock_write_iter+0x121/0x1c0
 ? sock_sendmsg+0x80/0x80
 __vfs_write+0x23e/0x370
 vfs_write+0xe7/0x230
 ksys_write+0xa1/0x120
 ? __ia32_sys_read+0x50/0x50
 ? __audit_syscall_exit+0x3ce/0x450
 do_syscall_64+0x73/0x200
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7ff6f6147c60
Code: 73 01 c3 48 8b 0d 28 12 2d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 5d 73 2d 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83
RSP: 002b:00007ffd772ead18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000034 RCX: 00007ff6f6147c60
RDX: 0000000000000034 RSI: 000055df30a31270 RDI: 0000000000000003
RBP: 000055df30a31270 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffd772ead70 R11: 0000000000000246 R12: 00007ffd772ead74
R13: 00007ffd772eae20 R14: 00007ffd772eae24 R15: 000055df2f12ddc0

Allocated by task 6052:
 kasan_kmalloc+0xa0/0xd0
 __kmalloc+0x10a/0x220
 ops_init+0x97/0x190
 register_pernet_operations+0x1ac/0x360
 register_pernet_subsys+0x24/0x40
 0xffffffffc0ea016d
 do_one_initcall+0x8b/0x253
 do_init_module+0xe3/0x335
 load_module+0x2fc0/0x3890
 __do_sys_finit_module+0x192/0x1c0
 do_syscall_64+0x73/0x200
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 6067:
 __kasan_slab_free+0x130/0x180
 kfree+0x90/0x1a0
 ops_free_list.part.7+0xa6/0xc0
 unregister_pernet_operations+0x18b/0x1f0
 unregister_pernet_subsys+0x1d/0x30
 ip_vs_cleanup+0x1d/0xd2f [ip_vs]
 __x64_sys_delete_module+0x20c/0x300
 do_syscall_64+0x73/0x200
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8881e9b26600 which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 2092 bytes inside of 4096-byte region [ffff8881e9b26600, ffff8881e9b27600)
The buggy address belongs to the page:
page:ffffea0007a6c800 count:1 mapcount:0 mapping:ffff888107c0e600 index:0x0 compound_mapcount: 0
flags: 0x17ffffc0008100(slab|head)
raw: 0017ffffc0008100 dead000000000100 dead000000000200 ffff888107c0e600
raw: 0000000000000000 0000000080070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

while unregistering ipvs module, ops_free_list calls
__ip_vs_cleanup, then nf_unregister_net_hooks be called to
do remove nf hook entries. It need a RCU period to finish,
however net->ipvs is set to NULL immediately, which will
trigger NULL pointer dereference when a packet is hooked
and handled by ip_vs_in where net->ipvs is dereferenced.

Another scene is ops_free_list call ops_free to free the
net_generic directly while __ip_vs_cleanup finished, then
calling ip_vs_in will triggers use-after-free.

This patch moves nf_unregister_net_hooks from __ip_vs_cleanup()
to __ip_vs_dev_cleanup(),  where rcu_barrier() is called by
unregister_pernet_device -> unregister_pernet_operations,
that will do the needed grace period.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: efe4160618 ("ipvs: convert to use pernet nf_hook api")
Suggested-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-05-21 18:31:09 +02:00
..
ip_vs_app.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
ip_vs_conn.c ipvs: don't show negative times in ip_vs_conn 2018-08-16 19:36:57 +02:00
ip_vs_core.c ipvs: Fix use-after-free in ip_vs_in 2019-05-21 18:31:09 +02:00
ip_vs_ctl.c genetlink: optionally validate strictly/dumps 2019-04-27 17:07:22 -04:00
ip_vs_dh.c ipvs: fix multiplicative hashing in sh/dh/lblc/lblcr algorithms 2018-04-09 10:15:27 +03:00
ip_vs_est.c netfilter: ipvs: Convert timers to use timer_setup() 2017-11-08 15:53:58 -08:00
ip_vs_fo.c
ip_vs_ftp.c ipvs: change some data types from int to bool 2019-03-01 14:19:04 +01:00
ip_vs_lblc.c ipvs: initialize tbl->entries in ip_vs_lblc_init_svc() 2018-04-27 00:20:33 +02:00
ip_vs_lblcr.c ipvs: initialize tbl->entries after allocation 2018-04-27 00:20:33 +02:00
ip_vs_lc.c
ip_vs_mh.c treewide: convert ISO_8859-1 text comments to utf-8 2018-08-23 18:48:43 -07:00
ip_vs_nfct.c ipvs: add full ipv6 support to nfct 2018-06-01 14:01:54 +02:00
ip_vs_nq.c netfilter: refcounter conversions 2017-03-17 12:49:43 +01:00
ip_vs_ovf.c ipvs: Add ovf scheduler 2015-08-21 09:08:39 -07:00
ip_vs_pe_sip.c ipvs: handle connections started by real-servers 2016-04-20 12:34:17 +10:00
ip_vs_pe.c
ip_vs_proto_ah_esp.c ipvs: avoid indirect calls when calculating checksums 2019-01-28 11:15:58 +01:00
ip_vs_proto_sctp.c ipvs: get sctphdr by sctphoff in sctp_csum_check 2019-03-01 14:28:44 +01:00
ip_vs_proto_tcp.c ipvs: change some data types from int to bool 2019-03-01 14:19:04 +01:00
ip_vs_proto_udp.c ipvs: change some data types from int to bool 2019-03-01 14:19:04 +01:00
ip_vs_proto.c ipvs: add assured state for conn templates 2018-07-18 11:26:40 +02:00
ip_vs_rr.c netfilter: refcounter conversions 2017-03-17 12:49:43 +01:00
ip_vs_sched.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2015-08-04 23:57:45 -07:00
ip_vs_sed.c netfilter: refcounter conversions 2017-03-17 12:49:43 +01:00
ip_vs_sh.c ipvs: fix multiplicative hashing in sh/dh/lblc/lblcr algorithms 2018-04-09 10:15:27 +03:00
ip_vs_sync.c iov_iter: Separate type from direction and use accessor functions 2018-10-24 00:41:07 +01:00
ip_vs_wlc.c netfilter: refcounter conversions 2017-03-17 12:49:43 +01:00
ip_vs_wrr.c netfilter: refcounter conversions 2017-03-17 12:49:43 +01:00
ip_vs_xmit.c ipvs: allow tunneling with gue encapsulation 2019-04-08 22:57:59 +02:00
Kconfig ipvs: fix dependency on nf_defrag_ipv6 2019-02-12 11:24:01 +01:00
Makefile netfilter: ipvs: Add configurations of Maglev hashing 2018-04-09 10:11:18 +03:00