syzbot


KASAN: slab-out-of-bounds Write in wp384_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: 2172d, last: 2153d

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 memcpy include/linux/string.h:345 [inline]
BUG: KASAN: slab-out-of-bounds in wp384_final+0x93/0xe0 crypto/wp512.c:1105
Write of size 48 at addr ffff8801b70856b0 by task syz-executor188/4473

CPU: 1 PID: 4473 Comm: syz-executor188 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
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 memcpy+0x37/0x50 mm/kasan/kasan.c:303
 memcpy include/linux/string.h:345 [inline]
 wp384_final+0x93/0xe0 crypto/wp512.c:1105
 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: 0033:0x440019
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:00007ffd31e8d908 EFLAGS: 00000217 ORIG_RAX: 00000000000000fa
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440019
RDX: 0000000020000300 RSI: 0000000020000040 RDI: 0000000000000017
RBP: 00000000006ca018 R08: 0000000020c61fc8 R09: 00000000004002c8
R10: 00000000000000fb R11: 0000000000000217 R12: 0000000000401940
R13: 00000000004019d0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4473:
 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 0:
(stack is not available)

The buggy address belongs to the object at ffff8801b70855c0
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 240 bytes inside of
 256-byte region [ffff8801b70855c0, ffff8801b70856c0)
The buggy address belongs to the page:
page:ffffea0006dc2140 count:1 mapcount:0 mapping:ffff8801da8007c0 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0006bb01c8 ffff8801da801648 ffff8801da8007c0
raw: 0000000000000000 ffff8801b70850c0 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b7085580: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff8801b7085600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801b7085680: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                           ^
 ffff8801b7085700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801b7085780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (27):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/06/09 13:20 upstream 7d3bf613e99a 866118af .config console log report syz C ci-upstream-kasan-gce-root
2018/06/09 10:21 upstream 7d3bf613e99a 866118af .config console log report syz C ci-upstream-kasan-gce
2018/06/08 09:23 upstream 68abbe729567 f7b27b7a .config console log report syz ci-upstream-kasan-gce-386
2018/06/27 12:23 upstream 813835028e9a 43e60f7e .config console log report ci-upstream-kasan-gce
2018/06/27 01:07 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce-root
2018/06/25 07:29 upstream 7daf201d7fe8 2064fc5c .config console log report ci-upstream-kasan-gce-root
2018/06/25 06:05 upstream 7daf201d7fe8 2064fc5c .config console log report ci-upstream-kasan-gce-root
2018/06/22 06:43 upstream 27db64f65f1b 095ef806 .config console log report ci-upstream-kasan-gce
2018/06/21 12:25 upstream 1abd8a8f39cd 095ef806 .config console log report ci-upstream-kasan-gce-root
2018/06/16 15:40 upstream 9215310cf13b 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/15 05:01 upstream b5d903c2d656 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/14 08:39 upstream be779f03d563 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/11 17:07 upstream f0dc7f9c6dd9 ae8bdb50 .config console log report ci-upstream-kasan-gce
2018/06/26 18:24 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce-386
2018/06/26 03:41 upstream 6f0d349d922b 2064fc5c .config console log report ci-upstream-kasan-gce-386
2018/06/24 09:39 upstream 77072ca59fdd 2064fc5c .config console log report ci-upstream-kasan-gce-386
2018/06/22 03:21 upstream 27db64f65f1b 095ef806 .config console log report ci-upstream-kasan-gce-386
2018/06/21 18:03 upstream 1abd8a8f39cd 095ef806 .config console log report ci-upstream-kasan-gce-386
2018/06/21 09:39 upstream 1abd8a8f39cd 095ef806 .config console log report ci-upstream-kasan-gce-386
2018/06/20 14:20 upstream 81e97f01371f 095ef806 .config console log report ci-upstream-kasan-gce-386
2018/06/19 22:15 upstream ba4dbdedd3ed 732e4256 .config console log report ci-upstream-kasan-gce-386
2018/06/18 10:30 upstream 9ffc59d57228 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/17 07:56 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/16 14:20 upstream 9215310cf13b 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/14 08:12 upstream be779f03d563 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/12 11:48 upstream 8efcf34a2639 112eec79 .config console log report ci-upstream-kasan-gce-386
2018/06/08 07:29 upstream 68abbe729567 f7b27b7a .config console log report ci-upstream-kasan-gce-386
* Struck through repros no longer work on HEAD.