[syzbot] KASAN: use-after-free Read in nfc_llcp_sock_unlink

From: syzbot
Date: Mon Mar 29 2021 - 11:44:23 EST

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Hello,

syzbot found the following issue on:

HEAD commit: 75887e88 Merge branch '40GbE' of git://git.kernel.org/pub/..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=12d6bb06d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=5adab0bdee099d7a
dashboard link: https://syzkaller.appspot.com/bug?extid=8b7c5fc0cfb74afee8d1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15c2db21d00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1091d4bed00000

The issue was bisected to:

commit 997acaf6b4b59c6a9c259740312a69ea549cc684
Author: Mark Rutland <mark.rutland@xxxxxxx>
Date: Mon Jan 11 15:37:07 2021 +0000

lockdep: report broken irq restoration

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12636d06d00000
final oops: https://syzkaller.appspot.com/x/report.txt?x=11636d06d00000
console output: https://syzkaller.appspot.com/x/log.txt?x=16636d06d00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8b7c5fc0cfb74afee8d1@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 997acaf6b4b5 ("lockdep: report broken irq restoration")

==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x3e6f/0x54c0 kernel/locking/lockdep.c:4770
Read of size 8 at addr ffff888144614468 by task syz-executor242/8422

CPU: 0 PID: 8422 Comm: syz-executor242 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232
__kasan_report mm/kasan/report.c:399 [inline]
kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
__lock_acquire+0x3e6f/0x54c0 kernel/locking/lockdep.c:4770
lock_acquire kernel/locking/lockdep.c:5510 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
__raw_write_lock include/linux/rwlock_api_smp.h:210 [inline]
_raw_write_lock+0x2a/0x40 kernel/locking/spinlock.c:295
nfc_llcp_sock_unlink+0x1d/0x1c0 net/nfc/llcp_core.c:32
llcp_sock_release+0x286/0x580 net/nfc/llcp_sock.c:640
__sock_release+0xcd/0x280 net/socket.c:599
sock_close+0x18/0x20 net/socket.c:1258
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
exit_task_work include/linux/task_work.h:30 [inline]
do_exit+0xbfc/0x2a60 kernel/exit.c:825
do_group_exit+0x125/0x310 kernel/exit.c:922
__do_sys_exit_group kernel/exit.c:933 [inline]
__se_sys_exit_group kernel/exit.c:931 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43db99
Code: Unable to access opcode bytes at RIP 0x43db6f.
RSP: 002b:00007ffdd4d753e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00000000004ae230 RCX: 000000000043db99
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000400488
R10: 0000000000400488 R11: 0000000000000246 R12: 00000000004ae230
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001

Allocated by task 1:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:427 [inline]
____kasan_kmalloc mm/kasan/common.c:506 [inline]
____kasan_kmalloc mm/kasan/common.c:465 [inline]
__kasan_kmalloc+0x99/0xc0 mm/kasan/common.c:515
kmalloc include/linux/slab.h:554 [inline]
kzalloc include/linux/slab.h:684 [inline]
nfc_llcp_register_device+0x45/0x9d0 net/nfc/llcp_core.c:1572
nfc_register_device+0x6d/0x360 net/nfc/core.c:1124
nfcsim_device_new+0x345/0x5c1 drivers/nfc/nfcsim.c:408
nfcsim_init+0x71/0x14d drivers/nfc/nfcsim.c:455
do_one_initcall+0x103/0x650 init/main.c:1226
do_initcall_level init/main.c:1299 [inline]
do_initcalls init/main.c:1315 [inline]
do_basic_setup init/main.c:1335 [inline]
kernel_init_freeable+0x63e/0x6c2 init/main.c:1537
kernel_init+0xd/0x1b8 init/main.c:1424
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Freed by task 8422:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
____kasan_slab_free mm/kasan/common.c:360 [inline]
____kasan_slab_free mm/kasan/common.c:325 [inline]
__kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367
kasan_slab_free include/linux/kasan.h:199 [inline]
slab_free_hook mm/slub.c:1562 [inline]
slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600
slab_free mm/slub.c:3161 [inline]
kfree+0xe5/0x7f0 mm/slub.c:4213
local_release net/nfc/llcp_core.c:175 [inline]
kref_put include/linux/kref.h:65 [inline]
nfc_llcp_local_put net/nfc/llcp_core.c:183 [inline]
nfc_llcp_local_put+0x194/0x200 net/nfc/llcp_core.c:178
llcp_sock_destruct+0x81/0x150 net/nfc/llcp_sock.c:950
__sk_destruct+0x4b/0x900 net/core/sock.c:1795
sk_destruct+0xbd/0xe0 net/core/sock.c:1839
__sk_free+0xef/0x3d0 net/core/sock.c:1850
sk_free+0x78/0xa0 net/core/sock.c:1861
sock_put include/net/sock.h:1803 [inline]
llcp_sock_release+0x3c9/0x580 net/nfc/llcp_sock.c:644
__sock_release+0xcd/0x280 net/socket.c:599
sock_close+0x18/0x20 net/socket.c:1258
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
exit_task_work include/linux/task_work.h:30 [inline]
do_exit+0xbfc/0x2a60 kernel/exit.c:825
do_group_exit+0x125/0x310 kernel/exit.c:922
__do_sys_exit_group kernel/exit.c:933 [inline]
__se_sys_exit_group kernel/exit.c:931 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888144614000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1128 bytes inside of
2048-byte region [ffff888144614000, ffff888144614800)
The buggy address belongs to the page:
page:ffffea0005118400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888144616000 pfn:0x144610
head:ffffea0005118400 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x57ff00000010200(slab|head)
raw: 057ff00000010200 ffffea00050f2008 ffffea00050f1e08 ffff888010842000
raw: ffff888144616000 0000000000080006 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff888144614300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888144614380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888144614400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888144614480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888144614500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
This report 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@xxxxxxxxxxxxxxxx.

syzbot will keep track of this issue. See:
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

Next message: syzbot: "[syzbot] KMSAN: uninit-value in hci_event_packet (3)"
Previous message: Simon Ser: "Re: [PATCH] drm: DON'T require each CRTC to have a unique primary plane"
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