general protection fault in tcp_sk_exit

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 0585df468e8f Merge tag 'media/v4.18-3' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=178f65b4400000
kernel config: https://syzkaller.appspot.com/x/.config?x=2dc0cd7c2eefb46f
dashboard link: https://syzkaller.appspot.com/bug?extid=fe060728040f2935968f
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [da...@davemloft.net edum...@google.com
kuz...@ms2.inr.ac.ru linux-...@vger.kernel.org net...@vger.kernel.org
yosh...@linux-ipv6.org]

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+fe0607...@syzkaller.appspotmail.com

syz-executor7 invoked oom-killer: gfp_mask=0x6000c0(GFP_KERNEL),
nodemask=(null), order=0, oom_score_adj=0
kasan: CONFIG_KASAN_INLINE enabled
syz-executor7 cpuset=
kasan: GPF could be caused by NULL-ptr deref or user memory access
/
general protection fault: 0000 [#1] SMP KASAN
CPU: 0 PID: 8621 Comm: syz-executor7 Not tainted 4.18.0-rc7+ #175
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
mems_allowed=0
RIP: 0010:tcp_sk_exit+0x5a/0x230 net/ipv4/tcp_ipv4.c:2496
Code:
CPU: 1 PID: 8606 Comm: syz-executor7 Not tainted 4.18.0-rc7+ #175
03
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
80
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
3c
02
00
dump_header+0x27b/0xf64 mm/oom_kill.c:432
0f
85
d0
01
00
00
49
8b
9d
08
09
00
00
48
oom_kill_process.cold.25+0x10/0x10bc mm/oom_kill.c:867
b8
00
00
00
00
00
fc
ff
df
48
8d
bb
90
00
00 00
out_of_memory+0xa8a/0x14d0 mm/oom_kill.c:1081
48
89
fa
48
mem_cgroup_out_of_memory+0x15e/0x210 mm/memcontrol.c:1212
c1
ea
03
mem_cgroup_oom_synchronize+0x713/0x940 mm/memcontrol.c:1557
<80>
3c
02
pagefault_out_of_memory+0xc8/0x197 mm/oom_kill.c:1107
00
0f
85
mm_fault_error+0x1de/0x380 arch/x86/mm/fault.c:1024
9d
__do_page_fault+0xd25/0xe50 arch/x86/mm/fault.c:1424
01
00
00 48
8b
do_page_fault+0xf6/0x8c0 arch/x86/mm/fault.c:1471
bb
90
00
00
00
bb
ff
ff
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1160
ff
RIP: 0033:0x40e33f
Code:
ff
0f
84 c8
RSP: 0018:ffff880199f07620 EFLAGS: 00010206
02 00
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90002216000
00 48
RDX: 0000000000000012 RSI: ffffffff85846199 RDI: 0000000000000090
83 bd
RBP: ffff880199f07668 R08: ffff8801d51ea480 R09: ffffed003b6046d6
78 ff
R10: ffffed003b6046d6 R11: ffff8801db0236b3 R12: 0000000000000001
ff ff
R13: ffff8801932f85c0 R14: ffffed00333e0ed8 R15: ffff880199f07740
00 0f
FS: 00007f13f4184700(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
84 f9
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
04 00
CR2: 0000000000625208 CR3: 00000001d0108000 CR4: 00000000001406f0
00 48
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
8b 95
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
68 ff
Call Trace:
ff ff
tcp_sk_init+0xdc6/0x12b0 net/ipv4/tcp_ipv4.c:2601
44 89
95 38
ff ff
ff 4c
8d ac
10 00
ops_init+0x101/0x560 net/core/net_namespace.c:128
f7 ff
ff <49>
setup_net+0x3d9/0x980 net/core/net_namespace.c:313
89 85
90 06
00 00
49 8d
85 10
03 00
00 49
89 95
copy_net_ns+0x2b8/0x4d0 net/core/net_namespace.c:436
98 06
00 00
41
RSP: 002b:0000000000a3fc20 EFLAGS: 00010206
create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107
RAX: 00007f13f4101000 RBX: 0000000000020000 RCX: 0000000000456b7a
RDX: 0000000000021000 RSI: 0000000000021000 RDI: 0000000000000000
RBP: 0000000000a3fd00 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000a3fdf0
R13: 00007f13f4121700 R14: 0000000000000003 R15: 0000000000000004
Task in
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206
/ile0
ksys_unshare+0x723/0xfb0 kernel/fork.c:2442
killed as a result of limit of
/ile0
memory: usage 64kB, limit 0kB, failcnt 20
memory+swap: usage 0kB, limit 9007199254740988kB, failcnt 0
kmem: usage 0kB, limit 9007199254740988kB, failcnt 0
Memory cgroup stats for
__do_sys_unshare kernel/fork.c:2510 [inline]
__se_sys_unshare kernel/fork.c:2508 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2508
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
/ile0
:
cache:0KB
rss:8KB
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456b29
rss_huge:0KB
Code: fd b4 fb
shmem:0KB
ff c3 66 2e 0f
mapped_file:0KB
1f 84 00 00 00
dirty:0KB
00 00 66 90 48
writeback:0KB
89 f8 48 89 f7
swap:0KB
48 89 d6 48
inactive_anon:0KB
89 ca 4d 89 c2 4d
active_anon:0KB
89 c8 4c 8b 4c 24 08
inactive_file:0KB
0f 05 <48> 3d 01
active_file:0KB
f0 ff ff 0f 83
unevictable:0KB
cb b4 fb ff c3
66 2e 0f 1f 84
[ pid ] uid tgid total_vm rss pgtables_bytes swapents oom_score_adj
name
00 00 00 00
[ 8606] 0 8606 17717 8731 131072 0 0
syz-executor7
RSP: 002b:00007f13f4183c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f13f41846d4 RCX: 0000000000456b29
Memory cgroup out of memory: Kill process 8606 (syz-executor7) score
8763000 or sacrifice child
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000060040200
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
Killed process 8606 (syz-executor7) total-vm:70868kB, anon-rss:2156kB,
file-rss:32768kB, shmem-rss:0kB
R13: 00000000004d6140 R14: 00000000004c9843 R15: 0000000000000001
Modules linked in:
Dumping ftrace buffer:
(ftrace buffer empty)
---[ end trace f4f449fcff085a6d ]---
RIP: 0010:tcp_sk_exit+0x5a/0x230 net/ipv4/tcp_ipv4.c:2496
Code: 03 80 3c 02 00 0f 85 d0 01 00 00 49 8b 9d 08 09 00 00 48 b8 00 00 00
00 00 fc ff df 48 8d bb 90 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f
85 9d 01 00 00 48 8b bb 90 00 00 00 bb ff ff ff ff
RSP: 0018:ffff880199f07620 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90002216000
RDX: 0000000000000012 RSI: ffffffff85846199 RDI: 0000000000000090
RBP: ffff880199f07668 R08: ffff8801d51ea480 R09: ffffed003b6046d6
R10: ffffed003b6046d6 R11: ffff8801db0236b3 R12: 0000000000000001
R13: ffff8801932f85c0 R14: ffffed00333e0ed8 R15: ffff880199f07740
FS: 00007f13f4184700(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000625208 CR3: 00000001d0108000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This bug is generated by a bot. It may contain errors.
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[Dmitry Vyukov]

Seems to stop happenning now and reports look somewhat corrupted.

#syz invalid

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