syzbot


KASAN: slab-out-of-bounds Read in crypto_morus640_decrypt_chunk

Status: fixed on 2018/07/09 18:05
Subsystems: crypto
[Documentation on labels]
Reported-by: syzbot+1fafa9c4cf42df33f716@syzkaller.appspotmail.com
Fix commit: a81ae8095712 crypto: morus640 - Fix out-of-bounds access
First crash: 2136d, last: 2129d
Discussions (1)
Title Replies (including bot) Last reply
KASAN: slab-out-of-bounds Read in crypto_morus640_decrypt_chunk 0 (2) 2018/06/13 11:32

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 crypto_morus640_load_a crypto/morus640.c:111 [inline]
BUG: KASAN: slab-out-of-bounds in crypto_morus640_decrypt_chunk+0xcf8/0xd20 crypto/morus640.c:278
Read of size 4 at addr ffff8801d95e8588 by task syz-executor643/4576

CPU: 0 PID: 4576 Comm: syz-executor643 Not tainted 4.17.0+ #100
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_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 crypto_morus640_load_a crypto/morus640.c:111 [inline]
 crypto_morus640_decrypt_chunk+0xcf8/0xd20 crypto/morus640.c:278
 crypto_morus640_process_crypt.isra.12+0x153/0x230 crypto/morus640.c:376
 crypto_morus640_crypt+0x42e/0x9f0 crypto/morus640.c:442
 crypto_morus640_decrypt+0x23e/0x3d0 crypto/morus640.c:485
 crypto_aead_decrypt include/crypto/aead.h:370 [inline]
 _aead_recvmsg crypto/algif_aead.c:315 [inline]
 aead_recvmsg+0x13cc/0x1ba0 crypto/algif_aead.c:334
 sock_recvmsg_nosec net/socket.c:818 [inline]
 sock_recvmsg+0xd0/0x110 net/socket.c:825
 ___sys_recvmsg+0x2b6/0x680 net/socket.c:2323
 __sys_recvmsg+0x112/0x260 net/socket.c:2372
 __do_sys_recvmsg net/socket.c:2382 [inline]
 __se_sys_recvmsg net/socket.c:2379 [inline]
 __x64_sys_recvmsg+0x78/0xb0 net/socket.c:2379
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43fef9
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:00007ffefc749938 EFLAGS: 00000207 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fef9
RDX: 0000000000000000 RSI: 0000000020002840 RDI: 0000000000000004
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000207 R12: 0000000000401820
R13: 00000000004018b0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4576:
 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]
 kzalloc include/linux/slab.h:706 [inline]
 skcipher_next_slow crypto/skcipher.c:253 [inline]
 skcipher_walk_next+0x750/0x1850 crypto/skcipher.c:357
 skcipher_walk_first+0x151/0x410 crypto/skcipher.c:442
 skcipher_walk_aead_common+0x7f8/0xbc0 crypto/skcipher.c:539
 skcipher_walk_aead_decrypt+0xc7/0x100 crypto/skcipher.c:572
 crypto_morus640_process_crypt.isra.12+0x9c/0x230 crypto/morus640.c:370
 crypto_morus640_crypt+0x42e/0x9f0 crypto/morus640.c:442
 crypto_morus640_decrypt+0x23e/0x3d0 crypto/morus640.c:485
 crypto_aead_decrypt include/crypto/aead.h:370 [inline]
 _aead_recvmsg crypto/algif_aead.c:315 [inline]
 aead_recvmsg+0x13cc/0x1ba0 crypto/algif_aead.c:334
 sock_recvmsg_nosec net/socket.c:818 [inline]
 sock_recvmsg+0xd0/0x110 net/socket.c:825
 ___sys_recvmsg+0x2b6/0x680 net/socket.c:2323
 __sys_recvmsg+0x112/0x260 net/socket.c:2372
 __do_sys_recvmsg net/socket.c:2382 [inline]
 __se_sys_recvmsg net/socket.c:2379 [inline]
 __x64_sys_recvmsg+0x78/0xb0 net/socket.c:2379
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 2859:
 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+0x302/0x360 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d95e8580
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff8801d95e8580, ffff8801d95e85a0)
The buggy address belongs to the page:
page:ffffea0007657a00 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801d95e8fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0007651a88 ffffea0007649c08 ffff8801da8001c0
raw: ffff8801d95e8fc1 ffff8801d95e8000 000000010000001e 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d95e8480: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d95e8500: 00 00 00 00 fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801d95e8580: 00 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
                      ^
 ffff8801d95e8600: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d95e8680: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/06/13 16:32 upstream f5b7769eb040 27c5f59f .config console log report syz C ci-upstream-kasan-gce-root
2018/06/13 12:05 upstream f5b7769eb040 27c5f59f .config console log report syz C ci-upstream-kasan-gce
2018/06/13 11:31 net-next-old f0dc7f9c6dd9 27c5f59f .config console log report syz C ci-upstream-net-kasan-gce
2018/06/20 10:35 upstream 81e97f01371f 095ef806 .config console log report ci-upstream-kasan-gce
2018/06/15 16:06 upstream 4c5e8fc62d6a 27c5f59f .config console log report ci-upstream-kasan-gce-386
2018/06/16 00:50 net-next-old f0dc7f9c6dd9 27c5f59f .config console log report ci-upstream-net-kasan-gce
2018/06/13 14:14 net-next-old f0dc7f9c6dd9 27c5f59f .config console log report ci-upstream-net-kasan-gce
2018/06/13 10:07 net-next-old f0dc7f9c6dd9 27c5f59f .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.