syzbot


KASAN: slab-out-of-bounds Read in sctp_send_reset_streams

Status: fixed on 2018/02/01 10:32
Subsystems: sctp
[Documentation on labels]
Reported-by: syzbot+0665d43fa62276c7a5e3372929aa0bab96260979@syzkaller.appspotmail.com
Fix commit: 2342b8d95bca sctp: make sure stream nums can match optlen in sctp_setsockopt_reset_streams
First crash: 2423d, last: 2407d

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in sctp_send_reset_streams+0xb03/0xc10 net/sctp/stream.c:323
Read of size 2 at addr ffff8801d8bc84c8 by task syzkaller012611/3087

CPU: 0 PID: 3087 Comm: syzkaller012611 Not tainted 4.15.0-rc2+ #207
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428
 sctp_send_reset_streams+0xb03/0xc10 net/sctp/stream.c:323
 sctp_setsockopt_reset_streams net/sctp/socket.c:3905 [inline]
 sctp_setsockopt+0x70d/0x5d50 net/sctp/socket.c:4195
 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968
 SYSC_setsockopt net/socket.c:1851 [inline]
 SyS_setsockopt+0x189/0x360 net/socket.c:1830
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x445659
RSP: 002b:00007f185ec6cdc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000445659
RDX: 0000000000000077 RSI: 0000000000000084 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000008 R09: 00007f185ec6d700
R10: 0000000020b24000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffdfc7e9fef R14: 00007f185ec6d9c0 R15: 0000000000000000

Allocated by task 3087:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3711 [inline]
 __kmalloc_track_caller+0x15e/0x760 mm/slab.c:3726
 memdup_user+0x2c/0x90 mm/util.c:164
 sctp_setsockopt_reset_streams net/sctp/socket.c:3897 [inline]
 sctp_setsockopt+0x6a6/0x5d50 net/sctp/socket.c:4195
 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968
 SYSC_setsockopt net/socket.c:1851 [inline]
 SyS_setsockopt+0x189/0x360 net/socket.c:1830
 entry_SYSCALL_64_fastpath+0x1f/0x96

Freed by task 1:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3491 [inline]
 kfree+0xca/0x250 mm/slab.c:3806
 kobject_uevent_env+0x248/0xbc0 lib/kobject_uevent.c:541
 kobject_uevent+0x1f/0x30 lib/kobject_uevent.c:558
 kernel_add_sysfs_param kernel/params.c:798 [inline]
 param_sysfs_builtin kernel/params.c:833 [inline]
 param_sysfs_init+0x3f9/0x474 kernel/params.c:954
 do_one_initcall+0x9e/0x330 init/main.c:826
 do_initcall_level init/main.c:892 [inline]
 do_initcalls init/main.c:900 [inline]
 do_basic_setup init/main.c:918 [inline]
 kernel_init_freeable+0x469/0x521 init/main.c:1066
 kernel_init+0x13/0x172 init/main.c:993
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441

The buggy address belongs to the object at ffff8801d8bc84c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff8801d8bc84c0, ffff8801d8bc84e0)
The buggy address belongs to the page:
page:00000000ea2ff4c3 count:1 mapcount:0 mapping:0000000075381a1b index:0xffff8801d8bc8fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d8bc8000 ffff8801d8bc8fc1 000000010000003b
raw: ffffea00076334a0 ffff8801db001240 ffff8801db0001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d8bc8380: fb fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc
 ffff8801d8bc8400: 00 05 fc fc fc fc fc fc 00 05 fc fc fc fc fc fc
>ffff8801d8bc8480: fb fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc
                                              ^
 ffff8801d8bc8500: fb fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff8801d8bc8580: 00 02 fc fc fc fc fc fc 00 02 fc fc fc fc fc fc
==================================================================

Crashes (73):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2017/12/05 05:56 upstream 2391f0b4808e de212f1a .config console log report syz C ci-upstream-kasan-gce
2017/12/06 19:21 upstream 328b4ed93b69 5d643f8e .config console log report syz C ci-upstream-kasan-gce-386
2017/12/05 06:25 upstream 2391f0b4808e de212f1a .config console log report syz C ci-upstream-kasan-gce-386
2017/12/11 16:47 mmots 82bcf1def3b5 27f5dfef .config console log report syz C ci-upstream-mmots-kasan-gce
2017/12/11 03:19 mmots 82bcf1def3b5 5ad0ce95 .config console log report syz C ci-upstream-mmots-kasan-gce
2017/12/09 05:45 linux-next ad4dac17f9d5 5ad0ce95 .config console log report syz C ci-upstream-next-kasan-gce
2017/12/08 20:31 linux-next ad4dac17f9d5 5ad0ce95 .config console log report syz C ci-upstream-next-kasan-gce
2017/12/15 17:46 upstream 032b4cc8ff84 ac20b98c .config console log report ci-upstream-kasan-gce
2017/12/15 16:30 upstream 032b4cc8ff84 ac20b98c .config console log report ci-upstream-kasan-gce
2017/12/15 12:46 upstream 032b4cc8ff84 ac20b98c .config console log report ci-upstream-kasan-gce
2017/12/15 11:35 upstream 032b4cc8ff84 ac20b98c .config console log report ci-upstream-kasan-gce
2017/12/15 11:01 upstream 032b4cc8ff84 ac20b98c .config console log report ci-upstream-kasan-gce
2017/12/15 07:55 upstream d455df0bcc00 ac20b98c .config console log report ci-upstream-kasan-gce
2017/12/15 07:54 upstream d455df0bcc00 ac20b98c .config console log report ci-upstream-kasan-gce
2017/12/15 03:48 upstream d455df0bcc00 ac20b98c .config console log report ci-upstream-kasan-gce
2017/12/14 18:38 upstream 7c5cac1bc717 ac20b98c .config console log report ci-upstream-kasan-gce
2017/12/14 05:21 upstream 7c5cac1bc717 06ea774d .config console log report ci-upstream-kasan-gce
2017/12/13 23:52 upstream d39a01eff9af 06ea774d .config console log report ci-upstream-kasan-gce
2017/12/13 20:30 upstream d39a01eff9af 06ea774d .config console log report ci-upstream-kasan-gce
2017/12/10 19:40 upstream 51090c5d6de0 5ad0ce95 .config console log report ci-upstream-kasan-gce
2017/12/10 08:13 upstream 4ded3bec65a0 5ad0ce95 .config console log report ci-upstream-kasan-gce
2017/12/10 06:45 upstream 4ded3bec65a0 5ad0ce95 .config console log report ci-upstream-kasan-gce
2017/12/09 23:07 upstream f335195adf04 5ad0ce95 .config console log report ci-upstream-kasan-gce
2017/12/15 13:24 upstream 032b4cc8ff84 ac20b98c .config console log report ci-upstream-kasan-gce-386
2017/12/15 10:54 upstream 032b4cc8ff84 ac20b98c .config console log report ci-upstream-kasan-gce-386
2017/12/15 01:32 upstream d455df0bcc00 ac20b98c .config console log report ci-upstream-kasan-gce-386
2017/12/14 19:57 upstream 7c5cac1bc717 ac20b98c .config console log report ci-upstream-kasan-gce-386
2017/12/14 09:37 upstream 7c5cac1bc717 ac20b98c .config console log report ci-upstream-kasan-gce-386
2017/12/14 04:01 upstream d39a01eff9af 06ea774d .config console log report ci-upstream-kasan-gce-386
2017/12/13 23:18 upstream d39a01eff9af 06ea774d .config console log report ci-upstream-kasan-gce-386
2017/12/13 20:31 upstream d39a01eff9af 06ea774d .config console log report ci-upstream-kasan-gce-386
2017/12/13 06:50 upstream d39a01eff9af ce7f2399 .config console log report ci-upstream-kasan-gce-386
2017/12/12 00:07 upstream 50c4c4e268a2 da131727 .config console log report ci-upstream-kasan-gce-386
2017/12/11 17:13 upstream 50c4c4e268a2 27f5dfef .config console log report ci-upstream-kasan-gce-386
2017/12/10 22:10 upstream 51090c5d6de0 5ad0ce95 .config console log report ci-upstream-kasan-gce-386
2017/12/10 17:57 upstream 51090c5d6de0 5ad0ce95 .config console log report ci-upstream-kasan-gce-386
2017/12/09 21:10 upstream f335195adf04 5ad0ce95 .config console log report ci-upstream-kasan-gce-386
2017/12/21 01:10 mmots 82bcf1def3b5 90a46995 .config console log report ci-upstream-mmots-kasan-gce
2017/12/20 19:16 mmots 82bcf1def3b5 90a46995 .config console log report ci-upstream-mmots-kasan-gce
2017/12/13 23:09 mmots 82bcf1def3b5 06ea774d .config console log report ci-upstream-mmots-kasan-gce
2017/12/11 23:40 mmots 82bcf1def3b5 da131727 .config console log report ci-upstream-mmots-kasan-gce
2017/12/11 04:54 linux-next ad4dac17f9d5 5ad0ce95 .config console log report ci-upstream-next-kasan-gce
2017/12/10 18:19 linux-next ad4dac17f9d5 5ad0ce95 .config console log report ci-upstream-next-kasan-gce
2017/12/10 15:32 linux-next ad4dac17f9d5 5ad0ce95 .config console log report ci-upstream-next-kasan-gce
2017/12/09 22:05 linux-next ad4dac17f9d5 5ad0ce95 .config console log report ci-upstream-next-kasan-gce
2017/12/09 10:28 linux-next ad4dac17f9d5 5ad0ce95 .config console log report ci-upstream-next-kasan-gce
2017/12/09 08:17 linux-next ad4dac17f9d5 5ad0ce95 .config console log report ci-upstream-next-kasan-gce
* Struck through repros no longer work on HEAD.