syzbot


KASAN: slab-out-of-bounds Write in sha512_finup

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: 2138d, last: 2122d

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 put_unaligned_be64 include/linux/unaligned/access_ok.h:65 [inline]
BUG: KASAN: slab-out-of-bounds in sha512_base_finish include/crypto/sha512_base.h:127 [inline]
BUG: KASAN: slab-out-of-bounds in sha512_finup+0x564/0x620 arch/x86/crypto/sha512_ssse3_glue.c:80
Write of size 8 at addr ffff8801ae495440 by task syz-executor501/4514

CPU: 0 PID: 4514 Comm: syz-executor501 Not tainted 4.17.0+ #93
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
 put_unaligned_be64 include/linux/unaligned/access_ok.h:65 [inline]
 sha512_base_finish include/crypto/sha512_base.h:127 [inline]
 sha512_finup+0x564/0x620 arch/x86/crypto/sha512_ssse3_glue.c:80
 sha512_avx2_finup arch/x86/crypto/sha512_ssse3_glue.c:244 [inline]
 sha512_avx2_final+0x28/0x30 arch/x86/crypto/sha512_ssse3_glue.c:250
 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: 0033:0x43ffa9
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:00007fff4f463d78 EFLAGS: 00000217 ORIG_RAX: 00000000000000fa
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043ffa9
RDX: 0000000020a53ffb RSI: 0000000020000100 RDI: 0000000000000017
RBP: 00000000006ca018 R08: 0000000020c61fc8 R09: 00000000004002c8
R10: 0000000000000053 R11: 0000000000000217 R12: 00000000004018d0
R13: 0000000000401960 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4514:
 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 ffff8801ae4953c0
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 0 bytes to the right of
 128-byte region [ffff8801ae4953c0, ffff8801ae495440)
The buggy address belongs to the page:
page:ffffea0006b92540 count:1 mapcount:0 mapping:ffff8801da800640 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0006b2fd08 ffffea0007646348 ffff8801da800640
raw: 0000000000000000 ffff8801ae495000 0000000100000015 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ae495300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801ae495380: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
>ffff8801ae495400: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                           ^
 ffff8801ae495480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801ae495500: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
==================================================================

Crashes (25):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/06/10 10:56 upstream a16afaf7928b 866118af .config console log report syz C ci-upstream-kasan-gce
2018/06/10 10:27 upstream a16afaf7928b 866118af .config console log report syz C ci-upstream-kasan-gce-root
2018/06/10 11:02 upstream a16afaf7928b 866118af .config console log report syz ci-upstream-kasan-gce-386
2018/06/26 20:12 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce
2018/06/26 17:21 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce-root
2018/06/25 20:37 upstream 6f0d349d922b 2064fc5c .config console log report ci-upstream-kasan-gce-root
2018/06/25 14:49 upstream 6f0d349d922b 2064fc5c .config console log report ci-upstream-kasan-gce
2018/06/24 22:46 upstream 7daf201d7fe8 2064fc5c .config console log report ci-upstream-kasan-gce-root
2018/06/24 02:04 upstream 5e2204832b20 2064fc5c .config console log report ci-upstream-kasan-gce-root
2018/06/23 16:20 upstream 5e2204832b20 2064fc5c .config console log report ci-upstream-kasan-gce
2018/06/21 22:56 upstream 27db64f65f1b 095ef806 .config console log report ci-upstream-kasan-gce
2018/06/21 03:41 upstream 1abd8a8f39cd 095ef806 .config console log report ci-upstream-kasan-gce
2018/06/19 22:10 upstream ba4dbdedd3ed 732e4256 .config console log report ci-upstream-kasan-gce
2018/06/17 23:01 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/16 00:10 upstream 4c5e8fc62d6a 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/14 15:03 upstream 2837461dbe6f 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/10 22:20 upstream 3ca24ce9ff76 866118af .config console log report ci-upstream-kasan-gce
2018/06/10 10:02 upstream a16afaf7928b 866118af .config console log report ci-upstream-kasan-gce-root
2018/06/26 17:21 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce-386
2018/06/25 05:57 upstream 7daf201d7fe8 2064fc5c .config console log report ci-upstream-kasan-gce-386
2018/06/24 15:53 upstream 77072ca59fdd 2064fc5c .config console log report ci-upstream-kasan-gce-386
2018/06/22 01:07 upstream 27db64f65f1b 095ef806 .config console log report ci-upstream-kasan-gce-386
2018/06/18 02:30 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/15 23:02 upstream 4c5e8fc62d6a 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/11 06:59 upstream 1aaccb5fa0ea 866118af .config console log report ci-upstream-kasan-gce-386
* Struck through repros no longer work on HEAD.