BUG: unable to handle kernel NULL pointer dereference in corrupted (2)

From: syzbot
Date: Wed Jul 18 2018 - 00:29:06 EST


Hello,

syzbot found the following crash on:

HEAD commit: dc989d2ce2c2 tools: bpftool: don't pass FEATURES_DUMP to l..
git tree: bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10a9a978400000
kernel config: https://syzkaller.appspot.com/x/.config?x=89129667b46496c3
dashboard link: https://syzkaller.appspot.com/bug?extid=c9ebf7fd9683e40ccebc
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=11974b2c400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14de7a58400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+c9ebf7fd9683e40ccebc@xxxxxxxxxxxxxxxxxxxxxxxxx

random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
random: sshd: uninitialized urandom read (32 bytes read)
IPVS: ftp: loaded support on port[0] = 21
BUG: unable to handle kernel NULL pointer dereference at 0000000000000072
==================================================================
PGD 1acfe1067
BUG: KASAN: stack-out-of-bounds in rcu_cblist_dequeue+0xaa/0xe0 kernel/rcu/rcu_segcblist.c:54
P4D 1acfe1067
Read of size 8 at addr ffff8801cfe1e340 by task syz-executor568/12240
PUD 1c551a067

PMD 0
CPU: 0 PID: 12240 Comm: syz-executor568 Not tainted 4.18.0-rc3+ #57
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Oops: 0002 [#1] SMP KASAN
Call Trace:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.18.0-rc3+ #57
<IRQ>
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
RIP: 0010:K512_4+0x6792/0x120eac
Code:
20
36
34
print_address_description+0x6c/0x20b mm/kasan/report.c:256
20
34
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
20
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
74
rcu_cblist_dequeue+0xaa/0xe0 kernel/rcu/rcu_segcblist.c:54
68
69
rcu_do_batch kernel/rcu/tree.c:2556 [inline]
invoke_rcu_callbacks kernel/rcu/tree.c:2818 [inline]
__rcu_process_callbacks kernel/rcu/tree.c:2785 [inline]
rcu_process_callbacks+0xf7e/0x1850 kernel/rcu/tree.c:2802
73
20
32
35
36
20
36
34
20
34
20
__do_softirq+0x2e8/0xb17 kernel/softirq.c:288
74
68
61
74
20
00
00
00
00
00
invoke_softirq kernel/softirq.c:368 [inline]
irq_exit+0x1d1/0x200 kernel/softirq.c:408
00
exiting_irq arch/x86/include/asm/apic.h:527 [inline]
smp_apic_timer_interrupt+0x186/0x730 arch/x86/kernel/apic/apic.c:1052
00
20
30
20
33
32
20
38
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
20
</IRQ>
31

32
Allocated by task 0:
<20>
(stack is not available)
74

61
Freed by task 3487688240:
72 67 65 74 5f 65 6e 74 72 79 20 39 36 20 32 34 20 35 20
RSP: 0018:ffff8801daf07980 EFLAGS: 00010202
RAX: ffffffff81674dc6 RBX: ffffffff88bf2c08 RCX: 0000000000000000
RDX: ffffffff88bf2c08 RSI: 0000000000000000 RDI: ffff8801cfea94a0
RBP: ffff8801daf07c88 R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff157bc71 R11: ffffffff8abde38b R12: ffff8801cfea94a0
R13: ffff8801cfea94a8 R14: dffffc0000000000 R15: ffff8801daf07c60
FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000072 CR3: 00000001cae8d000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
__do_softirq+0x2e8/0xb17 kernel/softirq.c:288
invoke_softirq kernel/softirq.c:368 [inline]
irq_exit+0x1d1/0x200 kernel/softirq.c:408
exiting_irq arch/x86/include/asm/apic.h:527 [inline]
smp_apic_timer_interrupt+0x186/0x730 arch/x86/kernel/apic/apic.c:1052
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
</IRQ>
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54
Code: c7 48 89 45 d8 e8 8a 2d 23 fa 48 8b 45 d8 e9 d2 fe ff ff 48 89 df e8 79 2d 23 fa eb 8a 90 90 90 90 90 90 90 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90
RSP: 0018:ffff8801d9af7c38 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 1ffff1003b35ef8a RCX: ffffffff81667982
RDX: 1ffffffff11e3610 RSI: 0000000000000004 RDI: ffffffff88f1b080
RBP: ffff8801d9af7c38 R08: ffffed003b5e46d7 R09: ffffed003b5e46d6
R10: ffffed003b5e46d6 R11: ffff8801daf236b3 R12: 0000000000000001
R13: ffff8801d9af7cf0 R14: ffffffff899ee920 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
default_idle+0xc7/0x450 arch/x86/kernel/process.c:500
arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:491
default_idle_call+0x6d/0x90 kernel/sched/idle.c:93
cpuidle_idle_call kernel/sched/idle.c:153 [inline]
do_idle+0x3aa/0x570 kernel/sched/idle.c:262
cpu_startup_entry+0x10c/0x120 kernel/sched/idle.c:368
start_secondary+0x433/0x5d0 arch/x86/kernel/smpboot.c:265
secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242
Modules linked in:
Dumping ftrace buffer:
(ftrace buffer empty)
CR2: 0000000000000072
---[ end trace 9d01a82a0b66f200 ]---
BUG: unable to handle kernel paging request at ffffffff8c3f7968
PGD 8e6d067
RIP: 0010:K512_4+0x6792/0x120eac
P4D 8e6d067
Code:
PUD 8e6e063
20
PMD 0
36
34
Thread overran stack, or stack corrupted
20 34
Oops: 0000 [#2] SMP KASAN
20
CPU: 0 PID: 12240 Comm: syz-executor568 Tainted: G D 4.18.0-rc3+ #57
74
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
68
RIP: 0010:depot_fetch_stack+0x10/0x30 lib/stackdepot.c:201
69
Code:
73
e8
20
c5
32
2e
35
47
36
fe
20
e9
36
b3
34
fd
20
ff
34
ff
20
e8
74
bb
68
2e
61
47
74
fe
20
e9
00
55
00
fd
00
ff
00
ff
00
90
00
90
00
90
20
90
30
90
20
90
33
89
32
f8
20
c1
38
ef
20
11
31
25
32
ff
<20>
ff
74
1f
61
00
72
81
67
e7
65
f0
74
3f
5f
00
65
00
6e
<48>
74
03
72
3c
79
c5
20
60
39
39
36
43
20
8b
32
8b
34
47
20
0c
35
48
20
83
c7
RSP: 0018:ffff8801daf07980 EFLAGS: 00010202
18
c7
RAX: ffffffff81674dc6 RBX: ffffffff88bf2c08 RCX: 0000000000000000
46 10
RDX: ffffffff88bf2c08 RSI: 0000000000000000 RDI: ffff8801cfea94a0
00
RBP: ffff8801daf07c88 R08: 0000000000000000 R09: 0000000000000000
00
R10: fffffbfff157bc71 R11: ffffffff8abde38b R12: ffff8801cfea94a0
00
R13: ffff8801cfea94a8 R14: dffffc0000000000 R15: ffff8801daf07c60
00
FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
RSP: 0018:ffff8801dae07898 EFLAGS: 00010006
CR2: 0000000000000072 CR3: 00000001cae8d000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
RAX: 00000000001f8801 RBX: ffff8801cfe1e514 RCX: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
RDX: 0000000000000000 RSI: ffff8801dae078a0 RDI: 0000000000003ff0


---
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