syzbot


KASAN: use-after-free Read in xfrm_policy_lookup_bytype

Status: fixed on 2019/03/06 07:43
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+87da0517ca1d154f0610@syzkaller.appspotmail.com
Fix commit: 12750abad517 xfrm: policy: fix infinite loop when merging src-nodes
First crash: 1925d, last: 1884d
Discussions (1)
Title Replies (including bot) Last reply
KASAN: use-after-free Read in xfrm_policy_lookup_bytype 0 (1) 2018/12/20 12:10

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __xfrm_policy_eval_candidates net/xfrm/xfrm_policy.c:2019 [inline]
BUG: KASAN: use-after-free in xfrm_policy_eval_candidates net/xfrm/xfrm_policy.c:2053 [inline]
BUG: KASAN: use-after-free in xfrm_policy_lookup_bytype+0xd27/0xdb0 net/xfrm/xfrm_policy.c:2113
Read of size 4 at addr ffff88809804a9f4 by task syz-executor0/14841

CPU: 0 PID: 14841 Comm: syz-executor0 Not tainted 5.0.0-rc3+ #37
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:134
 __xfrm_policy_eval_candidates net/xfrm/xfrm_policy.c:2019 [inline]
 xfrm_policy_eval_candidates net/xfrm/xfrm_policy.c:2053 [inline]
 xfrm_policy_lookup_bytype+0xd27/0xdb0 net/xfrm/xfrm_policy.c:2113
 xfrm_policy_lookup+0x7e/0x90 net/xfrm/xfrm_policy.c:2145
 xfrm_bundle_lookup net/xfrm/xfrm_policy.c:2939 [inline]
 xfrm_lookup_with_ifid+0x8cf/0x2a90 net/xfrm/xfrm_policy.c:3080
 xfrm_lookup net/xfrm/xfrm_policy.c:3172 [inline]
 xfrm_lookup_route+0x3b/0x1f0 net/xfrm/xfrm_policy.c:3183
 ip_route_output_flow+0xad/0xc0 net/ipv4/route.c:2582
 ip_route_connect include/net/route.h:309 [inline]
 __ip4_datagram_connect+0x7ae/0x1330 net/ipv4/datagram.c:51
 __ip6_datagram_connect+0xf13/0x1440 net/ipv6/datagram.c:191
 ip6_datagram_connect+0x30/0x50 net/ipv6/datagram.c:273
 inet_dgram_connect+0x150/0x2e0 net/ipv4/af_inet.c:571
 __sys_connect+0x357/0x490 net/socket.c:1664
 __do_sys_connect net/socket.c:1675 [inline]
 __se_sys_connect net/socket.c:1672 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1672
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458099
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5d1cf83c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099
RDX: 000000000000001c RSI: 0000000020000000 RDI: 0000000000000006
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5d1cf846d4
R13: 00000000004be4f7 R14: 00000000004ceb30 R15: 00000000ffffffff

Allocated by task 14099:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc mm/kasan/common.c:496 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
 __do_kmalloc_node mm/slab.c:3673 [inline]
 __kmalloc_node_track_caller+0x4e/0x70 mm/slab.c:3687
 __kmalloc_reserve.isra.0+0x40/0xe0 net/core/skbuff.c:140
 __alloc_skb+0x12d/0x730 net/core/skbuff.c:208
 alloc_skb include/linux/skbuff.h:1011 [inline]
 alloc_skb_with_frags+0xef/0x720 net/core/skbuff.c:5283
 sock_alloc_send_pskb+0x8c9/0xad0 net/core/sock.c:2091
 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2108
 __ip_append_data.isra.0+0x1b47/0x3350 net/ipv4/ip_output.c:998
 ip_make_skb+0x2b8/0x350 net/ipv4/ip_output.c:1531
 udp_sendmsg+0x28b5/0x3a40 net/ipv4/udp.c:1181
 inet_sendmsg+0x1af/0x740 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:631
 ___sys_sendmsg+0x409/0x910 net/socket.c:2116
 __sys_sendmmsg+0x246/0x730 net/socket.c:2211
 __do_sys_sendmmsg net/socket.c:2240 [inline]
 __se_sys_sendmmsg net/socket.c:2237 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2237
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 14099:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466
 __cache_free mm/slab.c:3487 [inline]
 kfree+0xcf/0x230 mm/slab.c:3806
 skb_free_head+0x93/0xb0 net/core/skbuff.c:553
 skb_release_data+0x6ea/0x970 net/core/skbuff.c:573
 skb_release_all+0x4d/0x60 net/core/skbuff.c:627
 __kfree_skb net/core/skbuff.c:641 [inline]
 kfree_skb net/core/skbuff.c:659 [inline]
 kfree_skb+0x199/0x580 net/core/skbuff.c:653
 __udp4_lib_mcast_deliver net/ipv4/udp.c:2177 [inline]
 __udp4_lib_rcv+0x2772/0x3180 net/ipv4/udp.c:2305
 udp_rcv+0x22/0x30 net/ipv4/udp.c:2480
 ip_protocol_deliver_rcu+0xb6/0xa20 net/ipv4/ip_input.c:208
 ip_local_deliver_finish+0x23b/0x390 net/ipv4/ip_input.c:234
 NF_HOOK include/linux/netfilter.h:289 [inline]
 NF_HOOK include/linux/netfilter.h:283 [inline]
 ip_local_deliver+0x1f0/0x740 net/ipv4/ip_input.c:255
 dst_input include/net/dst.h:450 [inline]
 ip_rcv_finish+0x1f4/0x2f0 net/ipv4/ip_input.c:414
 NF_HOOK include/linux/netfilter.h:289 [inline]
 NF_HOOK include/linux/netfilter.h:283 [inline]
 ip_rcv+0xed/0x620 net/ipv4/ip_input.c:524
 __netif_receive_skb_one_core+0x160/0x210 net/core/dev.c:4973
 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083
 netif_receive_skb_internal+0x11e/0x690 net/core/dev.c:5186
 napi_skb_finish net/core/dev.c:5665 [inline]
 napi_gro_receive+0x79a/0x9b0 net/core/dev.c:5698
 gro_cell_poll+0x132/0x1f0 net/core/gro_cells.c:46
 napi_poll net/core/dev.c:6346 [inline]
 net_rx_action+0x76d/0x1930 net/core/dev.c:6412
 __do_softirq+0x30b/0xb11 kernel/softirq.c:292

The buggy address belongs to the object at ffff88809804a940
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 180 bytes inside of
 1024-byte region [ffff88809804a940, ffff88809804ad40)
The buggy address belongs to the page:
page:ffffea0002601280 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0xffff88809804b240 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea00017e4488 ffffea0002461c08 ffff88812c3f0ac0
raw: ffff88809804b240 ffff88809804a040 0000000100000005 0000000000000000
page dumped because: kasan: bad access detected

kobject: 'loop5' (000000008862a7b9): fill_kobj_path: path = '/devices/virtual/block/loop5'
Memory state around the buggy address:
 ffff88809804a880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88809804a900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff88809804a980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff88809804aa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809804aa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (33):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/01/28 16:00 net-old abfd04f738c2 629c2a27 .config console log report ci-upstream-net-this-kasan-gce
2019/01/27 20:15 net-old abfd04f738c2 c73f090a .config console log report ci-upstream-net-this-kasan-gce
2019/01/25 14:25 net-old 6eea3527e68a b5d78bce .config console log report ci-upstream-net-this-kasan-gce
2019/01/21 10:00 net-old 6436408e814b fd37a550 .config console log report ci-upstream-net-this-kasan-gce
2019/01/10 19:20 net-old 85704cb8dcfd db9b6579 .config console log report ci-upstream-net-this-kasan-gce
2019/01/09 15:09 net-old d972f3dce8d1 45c0c1b1 .config console log report ci-upstream-net-this-kasan-gce
2019/01/09 02:55 net-old 977e4899c9b4 010ed08b .config console log report ci-upstream-net-this-kasan-gce
2019/01/08 01:22 net-old 0aaa81377c5a 69d69aa9 .config console log report ci-upstream-net-this-kasan-gce
2019/01/07 19:09 net-old 0aaa81377c5a 69d69aa9 .config console log report ci-upstream-net-this-kasan-gce
2019/01/05 16:08 net-old ec90ad334986 53be0a37 .config console log report ci-upstream-net-this-kasan-gce
2019/01/01 14:20 net-old 756af9c64232 3d85f48c .config console log report ci-upstream-net-this-kasan-gce
2019/01/01 13:32 net-old 756af9c64232 3d85f48c .config console log report ci-upstream-net-this-kasan-gce
2019/01/01 09:51 net-old 756af9c64232 3d85f48c .config console log report ci-upstream-net-this-kasan-gce
2018/12/29 18:34 net-old 7418e6520f22 a40793d7 .config console log report ci-upstream-net-this-kasan-gce
2018/12/28 19:32 net-old a3c9311f62b4 fc6ae81a .config console log report ci-upstream-net-this-kasan-gce
2019/01/29 17:45 net-next-old 085c4c7dd2b6 aa432daf .config console log report ci-upstream-net-kasan-gce
2019/01/29 15:46 net-next-old 085c4c7dd2b6 aa432daf .config console log report ci-upstream-net-kasan-gce
2019/01/29 15:40 net-next-old 085c4c7dd2b6 aa432daf .config console log report ci-upstream-net-kasan-gce
2019/01/29 07:26 net-next-old 085c4c7dd2b6 aa432daf .config console log report ci-upstream-net-kasan-gce
2019/01/29 00:04 net-next-old 085c4c7dd2b6 aa432daf .config console log report ci-upstream-net-kasan-gce
2019/01/28 14:56 net-next-old 085c4c7dd2b6 629c2a27 .config console log report ci-upstream-net-kasan-gce
2019/01/28 06:06 net-next-old 085c4c7dd2b6 c73f090a .config console log report ci-upstream-net-kasan-gce
2019/01/26 06:19 net-next-old 30e5c2c6bf28 ebf7a37c .config console log report ci-upstream-net-kasan-gce
2019/01/24 20:46 net-next-old 254764e55652 ce1ccf97 .config console log report ci-upstream-net-kasan-gce
2019/01/16 01:36 net-next-old 7939f8beecf1 79cb1a7c .config console log report ci-upstream-net-kasan-gce
2019/01/07 22:03 net-next-old b71acb0e3721 69d69aa9 .config console log report ci-upstream-net-kasan-gce
2018/12/28 20:25 net-next-old b71acb0e3721 fc6ae81a .config console log report ci-upstream-net-kasan-gce
2018/12/28 08:39 net-next-old b71acb0e3721 af317504 .config console log report ci-upstream-net-kasan-gce
2018/12/26 11:59 net-next-old 90cadbbf341d 8a41a0ad .config console log report ci-upstream-net-kasan-gce
2018/12/25 05:38 net-next-old ce28bb445388 8a41a0ad .config console log report ci-upstream-net-kasan-gce
2018/12/21 22:41 net-next-old fa2323325e8b 588075e6 .config console log report ci-upstream-net-kasan-gce
2018/12/21 07:44 net-next-old 962ad710f7d6 2b497001 .config console log report ci-upstream-net-kasan-gce
2018/12/19 18:06 net-next-old 33f18c96afdf fe2dc057 .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.