syzbot


KASAN: slab-out-of-bounds Write in tgr192_final

Status: fixed on 2018/07/09 18:05
Subsystems: crypto
[Documentation on labels]
Fix commit: 3619dec5103d dh key: fix rounding up KDF output length
First crash: 2147d, last: 2128d

Sample crash report:
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
==================================================================
BUG: KASAN: slab-out-of-bounds in tgr192_final+0x538/0x560 crypto/tgr192.c:603
Write of size 8 at addr ffff8801af53de20 by task syz-executor142/4504

CPU: 1 PID: 4504 Comm: syz-executor142 Not tainted 4.17.0+ #92
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+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_store8_noabort+0x17/0x20 mm/kasan/report.c:438
 tgr192_final+0x538/0x560 crypto/tgr192.c:603
 crypto_shash_final+0x104/0x260 crypto/shash.c:152
 kdf_ctr security/keys/dh.c:186 [inline]
 keyctl_dh_compute_kdf security/keys/dh.c:217 [inline]
 __keyctl_dh_compute+0x1184/0x1bc0 security/keys/dh.c:389
 keyctl_dh_compute+0xb9/0x100 security/keys/dh.c:425
 __do_sys_keyctl security/keys/keyctl.c:1741 [inline]
 __se_sys_keyctl security/keys/keyctl.c:1637 [inline]
 __x64_sys_keyctl+0x12a/0x3b0 security/keys/keyctl.c:1637
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440099
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 6b 45 00 00 c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007ffd04232a48 EFLAGS: 00000213 ORIG_RAX: 00000000000000fa
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440099
RDX: 0000000020000540 RSI: 0000000020000380 RDI: 0000000000000017
RBP: 00000000006ca018 R08: 00000000200005c0 R09: 00000000004002c8
R10: 0000000000000010 R11: 0000000000000213 R12: 00000000004019c0
R13: 0000000000401a50 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4504:
 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
 __do_kmalloc mm/slab.c:3718 [inline]
 __kmalloc+0x14e/0x760 mm/slab.c:3727
 kmalloc include/linux/slab.h:518 [inline]
 keyctl_dh_compute_kdf security/keys/dh.c:211 [inline]
 __keyctl_dh_compute+0xfe9/0x1bc0 security/keys/dh.c:389
 keyctl_dh_compute+0xb9/0x100 security/keys/dh.c:425
 __do_sys_keyctl security/keys/keyctl.c:1741 [inline]
 __se_sys_keyctl security/keys/keyctl.c:1637 [inline]
 __x64_sys_keyctl+0x12a/0x3b0 security/keys/keyctl.c:1637
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 2846:
 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
 single_release+0x8f/0xb0 fs/seq_file.c:609
 __fput+0x353/0x890 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x1e4/0x290 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:192 [inline]
 exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
 do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801af53de00
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes to the right of
 32-byte region [ffff8801af53de00, ffff8801af53de20)
The buggy address belongs to the page:
page:ffffea0006bd4f40 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801af53dfc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0006bf91c8 ffffea0006bdac88 ffff8801da8001c0
raw: ffff8801af53dfc1 ffff8801af53d000 000000010000003f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801af53dd00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801af53dd80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801af53de00: 00 00 00 00 fc fc fc fc fb fb fb fb fc fc fc fc
                               ^
 ffff8801af53de80: 00 00 00 00 fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801af53df00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================

Crashes (30):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/06/09 18:42 upstream 7d3bf613e99a 866118af .config console log report syz C ci-upstream-kasan-gce-root
2018/06/09 14:05 upstream 7d3bf613e99a 866118af .config console log report syz C ci-upstream-kasan-gce
2018/06/09 00:32 upstream 410feb75de24 866118af .config console log report syz C ci-upstream-kasan-gce-386
2018/06/27 12:28 upstream 813835028e9a 43e60f7e .config console log report ci-upstream-kasan-gce-root
2018/06/27 01:39 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce
2018/06/26 22:13 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce
2018/06/26 21:11 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce
2018/06/26 12:05 upstream 6f0d349d922b 2064fc5c .config console log report ci-upstream-kasan-gce
2018/06/26 03:06 upstream 6f0d349d922b 2064fc5c .config console log report ci-upstream-kasan-gce
2018/06/24 07:17 upstream 77072ca59fdd 2064fc5c .config console log report ci-upstream-kasan-gce-root
2018/06/20 14:42 upstream 81e97f01371f 095ef806 .config console log report ci-upstream-kasan-gce-root
2018/06/19 15:23 upstream ba4dbdedd3ed 732e4256 .config console log report ci-upstream-kasan-gce-root
2018/06/19 06:45 upstream ba4dbdedd3ed 45c54f75 .config console log report ci-upstream-kasan-gce-root
2018/06/18 03:03 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/18 00:24 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/17 21:38 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/17 18:23 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/17 14:24 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/17 14:00 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/16 09:22 upstream 9215310cf13b 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/16 00:14 upstream 4c5e8fc62d6a 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/10 22:03 upstream 3ca24ce9ff76 866118af .config console log report ci-upstream-kasan-gce
2018/06/27 16:29 upstream 813835028e9a 43e60f7e .config console log report ci-upstream-kasan-gce-386
2018/06/24 21:45 upstream 7daf201d7fe8 2064fc5c .config console log report ci-upstream-kasan-gce-386
2018/06/20 15:27 upstream 81e97f01371f 095ef806 .config console log report ci-upstream-kasan-gce-386
2018/06/19 15:53 upstream ba4dbdedd3ed 732e4256 .config console log report ci-upstream-kasan-gce-386
2018/06/16 23:20 upstream 35773c93817c 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/11 19:49 upstream f0dc7f9c6dd9 ae8bdb50 .config console log report ci-upstream-kasan-gce-386
2018/06/11 00:02 upstream 3ca24ce9ff76 866118af .config console log report ci-upstream-kasan-gce-386
2018/06/10 04:27 upstream a16afaf7928b 866118af .config console log report ci-upstream-kasan-gce-386
* Struck through repros no longer work on HEAD.