kernel BUG at include/linux/mm.h:LINE! (5)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    9e9322e5d28e selftest/net: Remove duplicate header
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13516233200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=47f2db597668ac40
dashboard link: https://syzkaller.appspot.com/bug?extid=5013d47539cdd43e7098
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=148763eb200000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1416ff3d200000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5013d47539cdd43e7098@xxxxxxxxxxxxxxxxxxxxxxxxx

flags: 0x1fffc0000000000()
raw: 01fffc0000000000 ffffea00025f6208 ffff88812fffc878 0000000000000000
raw: 0000000000000000 0000000000000003 00000000ffffff7f 0000000000000000
page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)
------------[ cut here ]------------
kernel BUG at include/linux/mm.h:546!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 7872 Comm: syz-executor445 Not tainted 5.0.0-rc7+ #95
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:put_page_testzero include/linux/mm.h:546 [inline]
RIP: 0010:put_page include/linux/mm.h:992 [inline]
RIP: 0010:__skb_frag_unref include/linux/skbuff.h:2837 [inline]
RIP: 0010:skb_release_data+0x5a5/0x7b0 net/core/skbuff.c:571
Code: f0 fe ff e9 b6 fb ff ff e8 38 b9 01 fc 4c 8d 63 ff e9 c8 fc ff ff e8  
2a b9 01 fc 48 c7 c6 80 c2 fe 87 4c 89 e7 e8 bb c6 2a fc <0f> 0b e8 14 b9  
01 fc 4d 8d 66 0e 48 b8 00 00 00 00 00 fc ff df 4c
RSP: 0018:ffff888086a0f708 EFLAGS: 00010293
RAX: ffff8880a3590440 RBX: ffffea00025dfa34 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81990662 RDI: ffffea00025dfa38
RBP: ffff888086a0f770 R08: 000000000000003e R09: ffffed1015d03ef9
R10: ffffed1015d03ef8 R11: ffff8880ae81f7c7 R12: ffffea00025dfa00
R13: ffff8880a4398c40 R14: 0000000000000001 R15: dffffc0000000000
FS:  00007fba67236700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fba67235e78 CR3: 0000000099c9f000 CR4: 00000000001406f0
Call Trace:
 skb_release_all+0x4d/0x60 net/core/skbuff.c:631
 __kfree_skb+0x16/0x30 net/core/skbuff.c:645
 sk_wmem_free_skb include/net/sock.h:1463 [inline]
 tcp_write_queue_purge+0x253/0x7d0 net/ipv4/tcp.c:2543
 tcp_disconnect+0x402/0x1890 net/ipv4/tcp.c:2583
 tcp_close+0xe37/0x10c0 net/ipv4/tcp.c:2384
 tls_sk_proto_close+0x40d/0x7a0 net/tls/tls_main.c:291
 inet_release+0x105/0x1f0 net/ipv4/af_inet.c:428
 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:473
 __sock_release+0xd3/0x2b0 net/socket.c:579
 sock_close+0x1b/0x30 net/socket.c:1162
 __fput+0x2df/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x92c/0x2fd0 kernel/exit.c:875
 do_group_exit+0x135/0x370 kernel/exit.c:979
 get_signal+0x399/0x1d50 kernel/signal.c:2575
 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x447589
Code: 6e 4d 6f 64 65 00 69 43 75 72 72 4f 66 66 73 00 69 4d 61 78 46 69 6c  
65 53 69 7a 65 00 69 4d 61 78 46 69 6c 65 73 00 69 46 69 <6c> 65 4e 75 6d  
44 69 67 69 74 73 00 62 44 65 6c 65 74 65 4f 6e 43
RSP: 002b:00007fba67235d98 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000006ddc68 RCX: 0000000000447589
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006ddc68
RBP: 00000000006ddc60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006ddc6c
R13: 0030656c69662f2e R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 3c84b12f07d7d40a ]---
RIP: 0010:put_page_testzero include/linux/mm.h:546 [inline]
RIP: 0010:put_page include/linux/mm.h:992 [inline]
RIP: 0010:__skb_frag_unref include/linux/skbuff.h:2837 [inline]
RIP: 0010:skb_release_data+0x5a5/0x7b0 net/core/skbuff.c:571
Code: f0 fe ff e9 b6 fb ff ff e8 38 b9 01 fc 4c 8d 63 ff e9 c8 fc ff ff e8  
2a b9 01 fc 48 c7 c6 80 c2 fe 87 4c 89 e7 e8 bb c6 2a fc <0f> 0b e8 14 b9  
01 fc 4d 8d 66 0e 48 b8 00 00 00 00 00 fc ff df 4c
RSP: 0018:ffff888086a0f708 EFLAGS: 00010293
RAX: ffff8880a3590440 RBX: ffffea00025dfa34 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81990662 RDI: ffffea00025dfa38
RBP: ffff888086a0f770 R08: 000000000000003e R09: ffffed1015d03ef9
R10: ffffed1015d03ef8 R11: ffff8880ae81f7c7 R12: ffffea00025dfa00
R13: ffff8880a4398c40 R14: 0000000000000001 R15: dffffc0000000000
FS:  00007fba67236700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fba67235e78 CR3: 0000000099c9f000 CR4: 00000000001406f0


---
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