syzbot


KASAN: use-after-free Read in tipc_nametbl_stop

Status: fixed on 2018/05/08 18:30
Subsystems: tipc
[Documentation on labels]
Reported-by: syzbot+d64b64afc55660106556@syzkaller.appspotmail.com
Fix commit: be47e41d77fb tipc: fix use-after-free in tipc_nametbl_stop
First crash: 2226d, last: 2220d
Discussions (4)
Title Replies (including bot) Last reply
[lkp-robot] 486ad79630 [ 15.532543] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 5 (5) 2018/05/03 18:02
486ad79630 ("origin"): BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 1 (1) 2018/05/03 03:47
[net 1/1] tipc: fix use-after-free in tipc_nametbl_stop 2 (2) 2018/04/18 17:48
KASAN: use-after-free Read in tipc_nametbl_stop 0 (1) 2018/04/16 05:57

Sample crash report:
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
==================================================================
BUG: KASAN: use-after-free in tipc_service_delete net/tipc/name_table.c:751 [inline]
BUG: KASAN: use-after-free in tipc_nametbl_stop+0x94e/0xd70 net/tipc/name_table.c:780
Read of size 8 at addr ffff8801cccdd2b0 by task kworker/u4:2/61

CPU: 1 PID: 61 Comm: kworker/u4:2 Not tainted 4.16.0+ #4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 tipc_service_delete net/tipc/name_table.c:751 [inline]
 tipc_nametbl_stop+0x94e/0xd70 net/tipc/name_table.c:780
 tipc_exit_net+0x2d/0x40 net/tipc/core.c:103
 ops_exit_list.isra.7+0xb0/0x160 net/core/net_namespace.c:152
 cleanup_net+0x51d/0xb20 net/core/net_namespace.c:523
 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145
 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411

Allocated by task 4490:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620
 kmalloc include/linux/slab.h:512 [inline]
 kzalloc include/linux/slab.h:701 [inline]
 tipc_service_create_range net/tipc/name_table.c:183 [inline]
 tipc_service_insert_publ net/tipc/name_table.c:207 [inline]
 tipc_nametbl_insert_publ+0x569/0x1910 net/tipc/name_table.c:371
 tipc_nametbl_publish+0x6c3/0xba0 net/tipc/name_table.c:618
 tipc_sk_publish+0x22a/0x510 net/tipc/socket.c:2604
 tipc_bind+0x206/0x330 net/tipc/socket.c:647
 __sys_bind+0x331/0x440 net/socket.c:1484
 SYSC_bind net/socket.c:1495 [inline]
 SyS_bind+0x24/0x30 net/socket.c:1493
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 61:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xd9/0x260 mm/slab.c:3813
 tipc_service_remove_publ.isra.8+0x909/0xc30 net/tipc/name_table.c:283
 tipc_service_delete net/tipc/name_table.c:753 [inline]
 tipc_nametbl_stop+0x746/0xd70 net/tipc/name_table.c:780
 tipc_exit_net+0x2d/0x40 net/tipc/core.c:103
 ops_exit_list.isra.7+0xb0/0x160 net/core/net_namespace.c:152
 cleanup_net+0x51d/0xb20 net/core/net_namespace.c:523
 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145
 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411

The buggy address belongs to the object at ffff8801cccdd280
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 48 bytes inside of
 64-byte region [ffff8801cccdd280, ffff8801cccdd2c0)
The buggy address belongs to the page:
page:ffffea0007333740 count:1 mapcount:0 mapping:ffff8801cccdd000 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801cccdd000 0000000000000000 0000000100000020
raw: ffffea00073a66a0 ffffea000735db60 ffff8801dac00340 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cccdd180: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
 ffff8801cccdd200: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff8801cccdd280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                                     ^
 ffff8801cccdd300: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
 ffff8801cccdd380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/04/16 07:16 upstream 71b8ebbf3d7b 7a67784c .config console log report syz C ci-upstream-kasan-gce-root
2018/04/16 02:58 net-next-old 5d1365940a68 7a67784c .config console log report syz C ci-upstream-net-kasan-gce
2018/04/16 03:17 upstream 71b8ebbf3d7b 7a67784c .config console log report syz ci-upstream-kasan-gce
2018/04/20 03:12 upstream 87ef12027b9b eae05cb0 .config console log report ci-upstream-kasan-gce-root
2018/04/20 00:51 upstream 87ef12027b9b eae05cb0 .config console log report ci-upstream-kasan-gce-root
2018/04/17 15:02 upstream a27fc14219f2 b80fd3b5 .config console log report ci-upstream-kasan-gce-root
2018/04/17 11:08 upstream a27fc14219f2 b80fd3b5 .config console log report ci-upstream-kasan-gce-root
2018/04/16 22:05 upstream 60cc43fc8884 802ac912 .config console log report ci-upstream-kasan-gce
2018/04/16 15:02 upstream 60cc43fc8884 802ac912 .config console log report ci-upstream-kasan-gce-root
2018/04/15 07:26 upstream 18b7fd1c93e5 7a67784c .config console log report ci-upstream-kasan-gce
2018/04/15 00:38 upstream 18b7fd1c93e5 7a67784c .config console log report ci-upstream-kasan-gce-root
2018/04/16 02:39 net-next-old 5d1365940a68 7a67784c .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.