KASAN: use-after-free Read in sha512_ctx_mgr_resubmit

From: syzbot
Date: Wed Aug 15 2018 - 12:00:08 EST

Next message: syzbot: "WARNING in wiphy_register (2)"
Previous message: Dave Kleikamp: "[GIT PULL] jfs patches for v4.19"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Hello,

syzbot found the following crash on:

HEAD commit: 7796916146b8 Merge branch 'x86-cpu-for-linus' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=164b1922400000
kernel config: https://syzkaller.appspot.com/x/.config?x=265bef9882cce8d7
dashboard link: https://syzkaller.appspot.com/bug?extid=d5455bac3ba1ee9114e5
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=1013478c400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1349c8aa400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d5455bac3ba1ee9114e5@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
BUG: KASAN: use-after-free in sha512_ctx_mgr_resubmit.part.3+0x3b1/0x4a0 arch/x86/crypto/sha512-mb/sha512_mb.c:136
Read of size 4 at addr ffff8801b0b9e838 by task kworker/0:1/13

CPU: 0 PID: 13 Comm: kworker/0:1 Not tainted 4.18.0+ #187
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: crypto mcryptd_flusher
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c9/0x2b4 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
sha512_ctx_mgr_resubmit.part.3+0x3b1/0x4a0 arch/x86/crypto/sha512-mb/sha512_mb.c:136
sha512_ctx_mgr_resubmit arch/x86/crypto/sha512-mb/sha512_mb.c:135 [inline]
sha512_ctx_mgr_flush+0x5c/0xb0 arch/x86/crypto/sha512-mb/sha512_mb.c:367
sha512_mb_flusher+0x27b/0x610 arch/x86/crypto/sha512-mb/sha512_mb.c:939
mcryptd_flusher+0x342/0x4b0 crypto/mcryptd.c:208
process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153
worker_thread+0x189/0x13c0 kernel/workqueue.c:2296
kthread+0x35a/0x420 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413

Allocated by task 23902:
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]
sock_kmalloc+0x156/0x1f0 net/core/sock.c:1996
hash_accept_parent_nokey+0x58/0x2e0 crypto/algif_hash.c:438
hash_accept_parent+0x5b/0x80 crypto/algif_hash.c:465
af_alg_accept+0x127/0x7d0 crypto/af_alg.c:296
alg_accept+0x46/0x60 crypto/af_alg.c:332
__sys_accept4+0x3b2/0x8a0 net/socket.c:1600
__do_sys_accept4 net/socket.c:1635 [inline]
__se_sys_accept4 net/socket.c:1632 [inline]
__x64_sys_accept4+0x97/0xf0 net/socket.c:1632
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 23902:
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
__sock_kfree_s net/core/sock.c:2017 [inline]
sock_kfree_s+0x29/0x60 net/core/sock.c:2023
hash_sock_destruct+0x157/0x1c0 crypto/algif_hash.c:427
__sk_destruct+0x107/0xa60 net/core/sock.c:1573
sk_destruct+0x78/0x90 net/core/sock.c:1608
__sk_free+0xcf/0x300 net/core/sock.c:1619
sk_free+0x42/0x50 net/core/sock.c:1630
sock_put include/net/sock.h:1667 [inline]
af_alg_release+0x6e/0x90 crypto/af_alg.c:126
__sock_release+0xd7/0x260 net/socket.c:600
sock_close+0x19/0x20 net/socket.c:1151
__fput+0x355/0x8b0 fs/file_table.c:209
____fput+0x15/0x20 fs/file_table.c:243
task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:192 [inline]
exit_to_usermode_loop+0x313/0x370 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 ffff8801b0b9e340
which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 1272 bytes inside of
2048-byte region [ffff8801b0b9e340, ffff8801b0b9eb40)
The buggy address belongs to the page:
page:ffffea0006c2e780 count:1 mapcount:0 mapping:ffff8801dac00c40 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea0007543a88 ffffea000760b188 ffff8801dac00c40
raw: 0000000000000000 ffff8801b0b9e340 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8801b0b9e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801b0b9e780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

ffff8801b0b9e800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

^
ffff8801b0b9e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801b0b9e900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

Next message: syzbot: "WARNING in wiphy_register (2)"
Previous message: Dave Kleikamp: "[GIT PULL] jfs patches for v4.19"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]