Date:   Mon, 10 Sep 2018 01:31:04 -0700
From:   syzbot <syzbot+5bbe234204453085d43e@...kaller.appspotmail.com>
To:     ast@...nel.org, daniel@...earbox.net, linux-kernel@...r.kernel.org,
        netdev@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: KASAN: use-after-free Read in psock_map_pop

Hello,

syzbot found the following crash on:

HEAD commit:    28619527b8a7 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree:       bpf
console output: https://syzkaller.appspot.com/x/log.txt?x=1442c149400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8f59875069d721b6
dashboard link: https://syzkaller.appspot.com/bug?extid=5bbe234204453085d43e
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17fb118e400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=169f48be400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5bbe234204453085d43e@...kaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x37c2/0x4ec0  
kernel/locking/lockdep.c:3291
Read of size 8 at addr ffff8801be270b88 by task syz-executor843/16792

CPU: 0 PID: 16792 Comm: syz-executor843 Not tainted 4.19.0-rc2+ #51
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+0x1c4/0x2b4 lib/dump_stack.c:113
  print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  __lock_acquire+0x37c2/0x4ec0 kernel/locking/lockdep.c:3291
  lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3901
  __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
  _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168
  spin_lock_bh include/linux/spinlock.h:334 [inline]
  psock_map_pop.isra.22+0x93/0x3b0 kernel/bpf/sockmap.c:298
  bpf_tcp_close+0x6ca/0x10c0 kernel/bpf/sockmap.c:380
  inet_release+0x104/0x1f0 net/ipv4/af_inet.c:428
  inet6_release+0x50/0x70 net/ipv6/af_inet6.c:457
  __sock_release+0xd7/0x250 net/socket.c:579
  sock_close+0x19/0x20 net/socket.c:1139
  __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:193 [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
RIP: 0033:0x4063c1
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 b4 17 00 00 c3 48  
83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48  
89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffdfa87cf10 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00000000004063c1
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000000000000003
RBP: 00000000006ddc30 R08: 00000000006ddc30 R09: 0000000000406c00
R10: 00007ffdfa87cf30 R11: 0000000000000293 R12: 00000000006ddc3c
R13: 00000000000003e8 R14: 0000000000000004 R15: 000000000000002d

Allocated by task 16796:
  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_node_trace+0x14c/0x740 mm/slab.c:3663
  kmalloc_node include/linux/slab.h:551 [inline]
  kzalloc_node include/linux/slab.h:718 [inline]
  smap_init_psock kernel/bpf/sockmap.c:1614 [inline]
  __sock_map_ctx_update_elem.isra.23+0x7a9/0x12f0 kernel/bpf/sockmap.c:1918
  sock_map_ctx_update_elem.isra.24+0x1a3/0xbe0 kernel/bpf/sockmap.c:1983
  sock_map_update_elem+0x22a/0x5a0 kernel/bpf/sockmap.c:2109
  map_update_elem+0x753/0xd50 kernel/bpf/syscall.c:799
  __do_sys_bpf kernel/bpf/syscall.c:2363 [inline]
  __se_sys_bpf kernel/bpf/syscall.c:2334 [inline]
  __x64_sys_bpf+0x32d/0x510 kernel/bpf/syscall.c:2334
  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 14:
  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:3813
  smap_gc_work+0x910/0xc70 kernel/bpf/sockmap.c:1607
  process_one_work+0xc90/0x1b90 kernel/workqueue.c:2153
  worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
  kthread+0x35a/0x420 kernel/kthread.c:246
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413

The buggy address belongs to the object at ffff8801be270940
  which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 584 bytes inside of
  1024-byte region [ffff8801be270940, ffff8801be270d40)
The buggy address belongs to the page:
page:ffffea0006f89c00 count:1 mapcount:0 mapping:ffff8801da800ac0 index:0x0  
compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea0006fa1408 ffffea0006f8ea08 ffff8801da800ac0
raw: 0000000000000000 ffff8801be270040 0000000100000007 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8801be270a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801be270b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8801be270b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                       ^
  ffff8801be270c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801be270c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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