syzbot


KASAN: use-after-free Read in xfrm_policy_insert_list

Status: fixed on 2019/03/06 07:43
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+5c4fda922a0a685e2bb5@syzkaller.appspotmail.com
Fix commit: 12750abad517 xfrm: policy: fix infinite loop when merging src-nodes
First crash: 2011d, last: 1969d

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in xfrm_policy_insert_list+0xd32/0xfb0 net/xfrm/xfrm_policy.c:1532
Read of size 1 at addr ffff8880a0685899 by task syz-executor5/13976

CPU: 0 PID: 13976 Comm: syz-executor5 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_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 xfrm_policy_insert_list+0xd32/0xfb0 net/xfrm/xfrm_policy.c:1532
 xfrm_policy_inexact_insert+0x155/0xda0 net/xfrm/xfrm_policy.c:1195
 xfrm_policy_insert+0x623/0x910 net/xfrm/xfrm_policy.c:1570
 xfrm_add_policy+0x2a1/0x6c0 net/xfrm/xfrm_user.c:1657
 xfrm_user_rcv_msg+0x458/0x8d0 net/xfrm/xfrm_user.c:2663
 netlink_rcv_skb+0x17d/0x410 net/netlink/af_netlink.c:2477
 xfrm_netlink_rcv+0x70/0x90 net/xfrm/xfrm_user.c:2671
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x574/0x770 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0xa05/0xf90 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:631
 ___sys_sendmsg+0x7ec/0x910 net/socket.c:2116
 __sys_sendmsg+0x112/0x270 net/socket.c:2154
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg net/socket.c:2161 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161
IPVS: set_ctl: invalid protocol: 251 0.0.0.0:20002
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
IPVS: set_ctl: invalid protocol: 251 0.0.0.0:20002
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458089
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:00007f3c881dec78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458089
RDX: 0000000000000000 RSI: 000000002014f000 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3c881df6d4
R13: 00000000004c568f R14: 00000000004d9400 R15: 00000000ffffffff

Allocated by task 16526:
 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
 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
 kmalloc include/linux/slab.h:545 [inline]
 kzalloc include/linux/slab.h:740 [inline]
 xfrm_policy_alloc+0xfb/0x530 net/xfrm/xfrm_policy.c:383
 xfrm_policy_construct+0x30/0x660 net/xfrm/xfrm_user.c:1599
 xfrm_add_policy+0x20a/0x6c0 net/xfrm/xfrm_user.c:1648
 xfrm_user_rcv_msg+0x458/0x8d0 net/xfrm/xfrm_user.c:2663
 netlink_rcv_skb+0x17d/0x410 net/netlink/af_netlink.c:2477
 xfrm_netlink_rcv+0x70/0x90 net/xfrm/xfrm_user.c:2671
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x574/0x770 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0xa05/0xf90 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:631
 ___sys_sendmsg+0x7ec/0x910 net/socket.c:2116
 __sys_sendmsg+0x112/0x270 net/socket.c:2154
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg net/socket.c:2161 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 13445:
 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
 xfrm_policy_destroy_rcu+0x48/0x60 net/xfrm/xfrm_policy.c:407
 __rcu_reclaim kernel/rcu/rcu.h:240 [inline]
 rcu_do_batch kernel/rcu/tree.c:2452 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2773 [inline]
 rcu_process_callbacks+0xc4a/0x1680 kernel/rcu/tree.c:2754
 __do_softirq+0x30b/0xb11 kernel/softirq.c:292

The buggy address belongs to the object at ffff8880a0685680
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 537 bytes inside of
 1024-byte region [ffff8880a0685680, ffff8880a0685a80)
The buggy address belongs to the page:
page:ffffea000281a100 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea0001a44288 ffffea000259b408 ffff88812c3f0ac0
raw: 0000000000000000 ffff8880a0684000 0000000100000007 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a0685780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a0685800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880a0685880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff8880a0685900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a0685980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (30):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/01/30 03:20 net-old abfd04f738c2 aa432daf .config console log report ci-upstream-net-this-kasan-gce
2019/01/23 03:33 net-old 56cb4e503499 b1ff06b2 .config console log report ci-upstream-net-this-kasan-gce
2019/01/21 17:16 net-old 6436408e814b badbbeee .config console log report ci-upstream-net-this-kasan-gce
2019/01/19 17:23 net-old 8a7fa0c35027 8aa587b0 .config console log report ci-upstream-net-this-kasan-gce
2019/01/18 13:58 net-old 88a8121dc1d3 5bf17c30 .config console log report ci-upstream-net-this-kasan-gce
2019/01/14 15:59 net-old 2f960bd05640 95485883 .config console log report ci-upstream-net-this-kasan-gce
2019/01/12 23:40 net-old 8d008e64a2eb c3f3344c .config console log report ci-upstream-net-this-kasan-gce
2019/01/07 09:16 net-old d4a7e9bb74b5 ee332608 .config console log report ci-upstream-net-this-kasan-gce
2019/01/04 10:48 net-old c5ee066333eb 7da23925 .config console log report ci-upstream-net-this-kasan-gce
2019/01/03 18:04 net-old c5ee066333eb 66fcd29b .config console log report ci-upstream-net-this-kasan-gce
2019/01/02 06:30 net-old 4087d2bc0d94 3d85f48c .config console log report ci-upstream-net-this-kasan-gce
2019/01/29 11:32 net-next-old 085c4c7dd2b6 aa432daf .config console log report ci-upstream-net-kasan-gce
2019/01/27 17:36 net-next-old 085c4c7dd2b6 c73f090a .config console log report ci-upstream-net-kasan-gce
2019/01/27 04:52 net-next-old a4b829949326 c73f090a .config console log report ci-upstream-net-kasan-gce
2019/01/21 22:00 net-next-old 28f9d1a3d4fe badbbeee .config console log report ci-upstream-net-kasan-gce
2019/01/13 14:59 net-next-old b71acb0e3721 c3f3344c .config console log report ci-upstream-net-kasan-gce
2019/01/10 09:46 net-next-old b71acb0e3721 45c0c1b1 .config console log report ci-upstream-net-kasan-gce
2019/01/08 14:29 net-next-old b71acb0e3721 37dd2683 .config console log report ci-upstream-net-kasan-gce
2019/01/06 13:47 net-next-old b71acb0e3721 94f8adb5 .config console log report ci-upstream-net-kasan-gce
2019/01/01 18:44 net-next-old b71acb0e3721 3d85f48c .config console log report ci-upstream-net-kasan-gce
2019/01/01 04:34 net-next-old b71acb0e3721 3d85f48c .config console log report ci-upstream-net-kasan-gce
2019/01/01 04:09 net-next-old b71acb0e3721 3d85f48c .config console log report ci-upstream-net-kasan-gce
2018/12/27 04:15 net-next-old 90cadbbf341d e747ec98 .config console log report ci-upstream-net-kasan-gce
2018/12/26 20:54 net-next-old 90cadbbf341d 8a41a0ad .config console log report ci-upstream-net-kasan-gce
2018/12/26 04:54 net-next-old 90cadbbf341d 8a41a0ad .config console log report ci-upstream-net-kasan-gce
2018/12/23 04:43 net-next-old ce28bb445388 e3bd7ab8 .config console log report ci-upstream-net-kasan-gce
2018/12/22 08:53 net-next-old ce28bb445388 603b5124 .config console log report ci-upstream-net-kasan-gce
2018/12/22 00:08 net-next-old fa2323325e8b 588075e6 .config console log report ci-upstream-net-kasan-gce
2018/12/19 20:51 net-next-old 33f18c96afdf fe2dc057 .config console log report ci-upstream-net-kasan-gce
2018/12/19 06:49 net-next-old a26d94bff4d5 4edaba93 .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.