syzbot


KASAN: slab-out-of-bounds Write in tgr160_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: 2120d, last: 2101d

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 tgr160_final+0x93/0xe0 crypto/tgr192.c:614
Write of size 20 at addr ffff8801d912c054 by task syz-executor926/4564

CPU: 0 PID: 4564 Comm: syz-executor926 Not tainted 4.17.0+ #89
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]
 tgr160_final+0x93/0xe0 crypto/tgr192.c:614
 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: 0033:0x440029
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:00007ffce89982d8 EFLAGS: 00000217 ORIG_RAX: 00000000000000fa
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440029
RDX: 0000000020a53ffb RSI: 0000000020000100 RDI: 0000000000000017
RBP: 00000000006ca018 R08: 0000000020c61fc8 R09: 00000000004002c8
R10: 0000000000000005 R11: 0000000000000217 R12: 0000000000401950
R13: 00000000004019e0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4564:
 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 2863:
 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 ffff8801d912c040
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 20 bytes inside of
 32-byte region [ffff8801d912c040, ffff8801d912c060)
The buggy address belongs to the page:
page:ffffea0007644b00 count:1 mapcount:0 mapping:ffff8801d912c000 index:0xffff8801d912cfc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d912c000 ffff8801d912cfc1 000000010000001a
raw: ffffea000764a060 ffffea0007646b60 ffff8801da8001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d912bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801d912bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801d912c000: 06 fc fc fc fc fc fc fc 00 00 00 fc fc fc fc fc
                                                    ^
 ffff8801d912c080: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d912c100: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================

Crashes (55):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/06/08 02:40 upstream 1c8c5a9d38f6 645e75f8 .config console log report syz C ci-upstream-kasan-gce
2018/06/08 03:29 upstream 1c8c5a9d38f6 645e75f8 .config console log report syz ci-upstream-kasan-gce-386
2018/06/26 20:00 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce
2018/06/26 07:56 upstream 6f0d349d922b 2064fc5c .config console log report ci-upstream-kasan-gce-root
2018/06/25 21:53 upstream 6f0d349d922b 2064fc5c .config console log report ci-upstream-kasan-gce
2018/06/25 07:39 upstream 7daf201d7fe8 2064fc5c .config console log report ci-upstream-kasan-gce
2018/06/24 08:20 upstream 77072ca59fdd 2064fc5c .config console log report ci-upstream-kasan-gce-root
2018/06/23 22:09 upstream 5e2204832b20 2064fc5c .config console log report ci-upstream-kasan-gce
2018/06/21 19:09 upstream 1abd8a8f39cd 095ef806 .config console log report ci-upstream-kasan-gce-root
2018/06/21 18:17 upstream 1abd8a8f39cd 095ef806 .config console log report ci-upstream-kasan-gce
2018/06/21 09:50 upstream 1abd8a8f39cd 095ef806 .config console log report ci-upstream-kasan-gce
2018/06/21 04:46 upstream 1abd8a8f39cd 095ef806 .config console log report ci-upstream-kasan-gce
2018/06/21 03:11 upstream 1abd8a8f39cd 095ef806 .config console log report ci-upstream-kasan-gce
2018/06/21 00:19 upstream 1abd8a8f39cd 095ef806 .config console log report ci-upstream-kasan-gce
2018/06/20 20:50 upstream 81e97f01371f 095ef806 .config console log report ci-upstream-kasan-gce
2018/06/18 21:09 upstream 9ffc59d57228 45c54f75 .config console log report ci-upstream-kasan-gce
2018/06/18 14:49 upstream 9ffc59d57228 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/17 22:48 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/17 19:05 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/17 11:02 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/15 14:47 upstream 4c5e8fc62d6a 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/14 19:20 upstream 2837461dbe6f 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/14 13:37 upstream 2837461dbe6f 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/14 13:27 upstream 2837461dbe6f 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/14 07:55 upstream be779f03d563 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/13 22:12 upstream be779f03d563 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/13 22:01 upstream be779f03d563 27c5f59f .config console log report ci-upstream-kasan-gce
2018/06/13 12:06 upstream f5b7769eb040 27c5f59f .config console log report ci-upstream-kasan-gce-root
2018/06/27 07:23 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce-386
2018/06/27 02:40 upstream 813835028e9a b0294c53 .config console log report ci-upstream-kasan-gce-386
2018/06/26 05:45 upstream 6f0d349d922b 2064fc5c .config console log report ci-upstream-kasan-gce-386
2018/06/25 23:34 upstream 6f0d349d922b 2064fc5c .config console log report ci-upstream-kasan-gce-386
2018/06/23 22:09 upstream 5e2204832b20 2064fc5c .config console log report ci-upstream-kasan-gce-386
2018/06/22 08:46 upstream 27db64f65f1b 095ef806 .config console log report ci-upstream-kasan-gce-386
2018/06/22 00:07 upstream 27db64f65f1b 095ef806 .config console log report ci-upstream-kasan-gce-386
2018/06/20 22:01 upstream 81e97f01371f 095ef806 .config console log report ci-upstream-kasan-gce-386
2018/06/19 06:11 upstream ba4dbdedd3ed 45c54f75 .config console log report ci-upstream-kasan-gce-386
2018/06/19 03:54 upstream ba4dbdedd3ed 45c54f75 .config console log report ci-upstream-kasan-gce-386
2018/06/18 09:23 upstream 9ffc59d57228 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/17 15:42 upstream ce397d215ccd 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/15 07:18 upstream b5d903c2d656 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/15 02:52 upstream b5d903c2d656 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/14 12:45 upstream 2837461dbe6f 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/13 19:17 upstream f5b7769eb040 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/13 04:54 upstream 0725d4e1b8b0 6dcbc435 .config console log report ci-upstream-kasan-gce-386
2018/06/13 02:30 upstream 0725d4e1b8b0 6dcbc435 .config console log report ci-upstream-kasan-gce-386
* Struck through repros no longer work on HEAD.