general protection fault in tipc_conn_close

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 97a8651c Linux 4.19.189
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12d9921ed00000
kernel config: https://syzkaller.appspot.com/x/.config?x=82311d18bf81a023
dashboard link: https://syzkaller.appspot.com/bug?extid=cae65bcdcf43a3593dd6

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cae65b...@syzkaller.appspotmail.com

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 15667 Comm: kworker/u4:6 Not tainted 4.19.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:tipc_conn_close+0x48/0x140 net/tipc/topsrv.c:165
Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 eb 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5d 08 48 8d 7b 20 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 be 00 00 00 4c 8b 6b 20 4d 8d a5 60 03 00 00 4c
RSP: 0018:ffff888226167bb0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff11003149d4f
RDX: 0000000000000004 RSI: ffffffff87b9c774 RDI: 0000000000000020
RBP: ffff888025f1f280 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880aaf48a50
R13: ffffed10155e9151 R14: ffff888025f1f288 R15: ffff888025f1f280
FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f069d672210 CR3: 000000009e63f000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
tipc_topsrv_stop net/tipc/topsrv.c:701 [inline]
tipc_topsrv_exit_net+0x27b/0x5c0 net/tipc/topsrv.c:722
ops_exit_list+0xa5/0x150 net/core/net_namespace.c:153
cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:553
process_one_work+0x864/0x1570 kernel/workqueue.c:2152
worker_thread+0x64c/0x1130 kernel/workqueue.c:2295
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Modules linked in:
---[ end trace 407c8dd3fc5c2eb5 ]---
RIP: 0010:tipc_conn_close+0x48/0x140 net/tipc/topsrv.c:165
Code: fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 eb 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5d 08 48 8d 7b 20 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 be 00 00 00 4c 8b 6b 20 4d 8d a5 60 03 00 00 4c
RSP: 0018:ffff888226167bb0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff11003149d4f
RDX: 0000000000000004 RSI: ffffffff87b9c774 RDI: 0000000000000020
RBP: ffff888025f1f280 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880aaf48a50
R13: ffffed10155e9151 R14: ffff888025f1f288 R15: ffff888025f1f280
FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000546f98 CR3: 00000000b2ccc000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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 syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 59456c9cc40c Linux 4.19.204
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=172e1c89300000
kernel config: https://syzkaller.appspot.com/x/.config?x=a84b4514346e13dc
dashboard link: https://syzkaller.appspot.com/bug?extid=cae65bcdcf43a3593dd6
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14dff01e300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10466c99300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cae65b...@syzkaller.appspotmail.com

IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
==================================================================
BUG: KASAN: use-after-free in tipc_conn_close+0x122/0x140 net/tipc/topsrv.c:165
Read of size 8 at addr ffff888099305a08 by task kworker/u4:3/435

CPU: 0 PID: 435 Comm: kworker/u4:3 Not tainted 4.19.204-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net

Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
kasan_report mm/kasan/report.c:412 [inline]
__asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
tipc_conn_close+0x122/0x140 net/tipc/topsrv.c:165

tipc_topsrv_stop net/tipc/topsrv.c:701 [inline]
tipc_topsrv_exit_net+0x27b/0x5c0 net/tipc/topsrv.c:722
ops_exit_list+0xa5/0x150 net/core/net_namespace.c:153
cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:553

process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296

kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 23:
kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
kmalloc include/linux/slab.h:515 [inline]
kzalloc include/linux/slab.h:709 [inline]
tipc_conn_alloc+0x43/0x4f0 net/tipc/topsrv.c:192
tipc_topsrv_accept+0x1b5/0x280 net/tipc/topsrv.c:470
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296

kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Freed by task 23:
__cache_free mm/slab.c:3503 [inline]
kfree+0xcc/0x210 mm/slab.c:3822
tipc_conn_kref_release net/tipc/topsrv.c:150 [inline]
kref_put include/linux/kref.h:70 [inline]
conn_put+0x2cd/0x3a0 net/tipc/topsrv.c:155
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296

kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

The buggy address belongs to the object at ffff888099305a00
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 8 bytes inside of
512-byte region [ffff888099305a00, ffff888099305c00)
The buggy address belongs to the page:
page:ffffea000264c140 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea00028b6b88 ffffea0002cd2b08 ffff88813bff0940
raw: 0000000000000000 ffff888099305000 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff888099305900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888099305980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888099305a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888099305a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888099305b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================