BUG: unable to handle kernel NULL pointer dereference in padata_serial_worker

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: ab9dfda2 Linux 4.14.180
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16dccb94100000
kernel config: https://syzkaller.appspot.com/x/.config?x=221566a7407ce2de
dashboard link: https://syzkaller.appspot.com/bug?extid=d4e9d5a87c97669a88ec
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

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+d4e9d5...@syzkaller.appspotmail.com

TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: (null)
PGD 87c26067 P4D 87c26067 PUD 87c27067 PMD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 7387 Comm: kworker/1:4 Not tainted 4.14.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: pencrypt padata_serial_worker
task: ffff888051218600 task.stack: ffff888051220000
RIP: 0010: (null)
RSP: 0018:ffff888051227cc8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff88803f288cd0 RCX: 1ffff1100a244fa1
RDX: 1ffff11007e51192 RSI: 0000000000000000 RDI: ffff88803f288c80
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000002
R10: ffff888051218ed8 R11: ffff888051218600 R12: 0000000000000001
R13: ffff888051227d08 R14: ffff88803f288cd8 R15: ffff8882191d51c0
FS: 0000000000000000(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000087c25000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
padata_serial_worker+0x269/0x400 kernel/padata.c:317
process_one_work+0x813/0x1540 kernel/workqueue.c:2116
worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: Bad RIP value.
RIP: (null) RSP: ffff888051227cc8
CR2: 0000000000000000
---[ end trace 8e8d64d7f19dad87 ]---


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 27ce4f2a Linux 4.14.206
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16ec97be500000
kernel config: https://syzkaller.appspot.com/x/.config?x=32258a0e1fac372d
dashboard link: https://syzkaller.appspot.com/bug?extid=d4e9d5a87c97669a88ec
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1128cec2500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11e4447a500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d4e9d5...@syzkaller.appspotmail.com

audit: type=1804 audit(1605498664.442:2): pid=8012 uid=0 auid=0 ses=5 op="invalid_pcr" cause="open_writers" comm="syz-executor716" name="/root/bus" dev="sda1" ino=15707 res=1

TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: (null)

PGD a1b7b067 P4D a1b7b067 PUD aa629067 PMD 0

Oops: 0010 [#1] PREEMPT SMP KASAN
Modules linked in:

CPU: 0 PID: 3299 Comm: kworker/0:2 Not tainted 4.14.206-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: pencrypt padata_serial_worker

task: ffff8880aa6f0600 task.stack: ffff8880aabc8000
RIP: 0010: (null)
RSP: 0018:ffff8880aabcfcd0 EFLAGS: 00010296
RAX: 0000000000000000 RBX: ffff8880a3888090 RCX: 1ffff11015579fa2
RDX: 1ffff1101471100a RSI: 0000000000000000 RDI: ffff8880a3888040
RBP: dffffc0000000000 R08: ffffe8ffffc27170 R09: 0000000000000002
R10: 0000000000000000 R11: ffff8880aa6f0600 R12: 0000000000000001
R13: ffff8880aabcfd10 R14: ffff8880b0f7ff00 R15: ffff8880a3888098
FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 0000000000000000 CR3: 000000009f028000 CR4: 00000000001406f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

padata_serial_worker+0x232/0x3e0 kernel/padata.c:307
process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250

kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: Bad RIP value.

RIP: (null) RSP: ffff8880aabcfcd0
CR2: 0000000000000000
---[ end trace f6b31047ff78f7a3 ]---