syzbot


KASAN: use-after-free Read in crypto_gcm_init_common

Status: fixed on 2019/11/08 08:43
Subsystems: crypto
[Documentation on labels]
Reported-by: syzbot+e736399a2c4054612307@syzkaller.appspotmail.com
Fix commit: 9354544cbccf net/tls: fix page double free on TX cleanup
First crash: 2034d, last: 1966d
Cause bisection: introduced by (bisect log) :
commit 428490e38b2e352812e0b765d8bceafab0ec441d
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Wed Sep 20 14:58:39 2017 +0000

  security/keys: rewrite all of big_key crypto

Crash: KASAN: use-after-free Write in padata_parallel_worker (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit 9354544cbccf68da1b047f8fb7b47630e3c8a59d
Author: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Date: Mon Jun 24 04:26:58 2019 +0000

  net/tls: fix page double free on TX cleanup

  
Discussions (2)
Title Replies (including bot) Last reply
KASAN: use-after-free Read in crypto_gcm_init_common 3 (6) 2019/11/07 20:05
Reminder: 17 open syzbot bugs in "net/tls" subsystem 1 (1) 2019/06/25 05:50

Sample crash report:
audit: type=1800 audit(1541644536.564:30): pid=5568 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0
sshd (5709) used greatest stack depth: 15744 bytes left
==================================================================
BUG: KASAN: use-after-free in memcpy include/linux/string.h:352 [inline]
BUG: KASAN: use-after-free in crypto_gcm_init_common+0xe2/0x710 crypto/gcm.c:181
Read of size 12 at addr ffff8801d2c05b00 by task kworker/1:2/2856

CPU: 1 PID: 2856 Comm: kworker/1:2 Not tainted 4.20.0-rc1+ #102
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: pencrypt padata_parallel_worker
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.8+0x242/0x309 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+0x23/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:352 [inline]
 crypto_gcm_init_common+0xe2/0x710 crypto/gcm.c:181
 crypto_gcm_encrypt+0xe2/0x6b0 crypto/gcm.c:479
 crypto_aead_encrypt include/crypto/aead.h:364 [inline]
 pcrypt_aead_enc+0xd6/0x340 crypto/pcrypt.c:143
 padata_parallel_worker+0x49d/0x760 kernel/padata.c:86
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Allocated by task 5737:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620
 kmalloc include/linux/slab.h:546 [inline]
 tls_set_sw_offload+0xcb3/0x1390 net/tls/tls_sw.c:1945
 do_tls_setsockopt_conf net/tls/tls_main.c:467 [inline]
 do_tls_setsockopt net/tls/tls_main.c:514 [inline]
 tls_setsockopt+0x689/0x770 net/tls/tls_main.c:533
 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2978
 __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902
 __do_sys_setsockopt net/socket.c:1913 [inline]
 __se_sys_setsockopt net/socket.c:1910 [inline]
 __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 5737:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xcf/0x230 mm/slab.c:3817
 tls_sk_proto_close+0x5fa/0x750 net/tls/tls_main.c:277
 inet_release+0x104/0x1f0 net/ipv4/af_inet.c:428
 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:458
 __sock_release+0xd7/0x250 net/socket.c:579
 sock_close+0x19/0x20 net/socket.c:1141
 __fput+0x385/0xa30 fs/file_table.c:278
 ____fput+0x15/0x20 fs/file_table.c:309
 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x318/0x380 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+0x6be/0x820 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d2c05b00
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8801d2c05b00, ffff8801d2c05b20)
The buggy address belongs to the page:
page:ffffea00074b0140 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801d2c05fc1
flags: 0x2fffc0000000200(slab)
raw: 02fffc0000000200 ffffea00074b04c8 ffffea000755e548 ffff8801da8001c0
raw: ffff8801d2c05fc1 ffff8801d2c05000 000000010000002e 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d2c05a00: 06 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d2c05a80: fb fb fb fb fc fc fc fc 00 00 01 fc fc fc fc fc
>ffff8801d2c05b00: fb fb fb fb fc fc fc fc 05 fc fc fc fc fc fc fc
                   ^
 ffff8801d2c05b80: 06 fc fc fc fc fc fc fc 06 fc fc fc fc fc fc fc
 ffff8801d2c05c00: 06 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/11/08 02:40 upstream e09d51adfbb1 e85d2a61 .config console log report syz C ci-upstream-kasan-gce-smack-root
2018/11/07 15:15 upstream 8053e5b93eca 8bd6bd63 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2018/11/05 10:33 upstream 4710e78940d8 8bd6bd63 .config console log report syz C ci-upstream-kasan-gce
2018/11/04 11:21 net-old 12480e3b1698 8bd6bd63 .config console log report syz C ci-upstream-net-this-kasan-gce
2018/11/04 08:34 net-next-old 7c6c54b505b8 8bd6bd63 .config console log report syz C ci-upstream-net-kasan-gce
2018/11/09 00:45 linux-next f7af6d2c48bf e85d2a61 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2018/11/29 21:11 upstream 60b548237fed 4b6d14f2 .config console log report ci-upstream-kasan-gce-root
2018/11/20 15:09 upstream f2ce1065e767 9bc2a903 .config console log report ci-upstream-kasan-gce-386
2019/01/11 03:09 net-old b19bce0335e2 80dde172 .config console log report ci-upstream-net-this-kasan-gce
2019/01/10 13:22 net-next-old b71acb0e3721 db9b6579 .config console log report ci-upstream-net-kasan-gce
2019/01/09 12:45 net-next-old b71acb0e3721 45c0c1b1 .config console log report ci-upstream-net-kasan-gce
2018/11/30 03:07 net-next-old e561bb29b650 66071e27 .config console log report ci-upstream-net-kasan-gce
2018/11/05 12:42 net-next-old 7c6c54b505b8 8bd6bd63 .config console log report ci-upstream-net-kasan-gce
2018/11/03 19:34 net-next-old 7c6c54b505b8 8bd6bd63 .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.