Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 2 UID: 0 PID: 6160 Comm: kworker/u32:16 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: krdsd rds_tcp_accept_worker
RIP: 0010:rds_tcp_accept_one+0x9aa/0xd90 net/rds/tcp_listen.c:319
Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 b1 03 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 18 49 8d 7c 24 12 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 76 03 00 00
RSP: 0018:ffffc900030dfb68 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8880273dca00 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffffffff8adb775a RDI: 0000000000000012
RBP: ffff88802c82e280 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 1ffffffff1cfe929 R12: 0000000000000000
R13: ffff888038c28000 R14: ffff888037bd0000 R15: ffff888038c28020
FS:  0000000000000000(0000) GS:ffff8880d654a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f05cc04e9d3 CR3: 000000000e598000 CR4: 0000000000352ef0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rds_tcp_accept_worker+0x41/0x60 net/rds/tcp.c:524
 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
 process_scheduled_works kernel/workqueue.c:3358 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
 kthread+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:rds_tcp_accept_one+0x9aa/0xd90 net/rds/tcp_listen.c:319
Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 b1 03 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 18 49 8d 7c 24 12 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 76 03 00 00
RSP: 0018:ffffc900030dfb68 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8880273dca00 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffffffff8adb775a RDI: 0000000000000012
RBP: ffff88802c82e280 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 1ffffffff1cfe929 R12: 0000000000000000
R13: ffff888038c28000 R14: ffff888037bd0000 R15: ffff888038c28020
FS:  0000000000000000(0000) GS:ffff8880d664a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000002c0fd000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	fa                   	cli
   1:	48 c1 ea 03          	shr    $0x3,%rdx
   5:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   9:	0f 85 b1 03 00 00    	jne    0x3c0
   f:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  16:	fc ff df
  19:	4d 8b 64 24 18       	mov    0x18(%r12),%r12
  1e:	49 8d 7c 24 12       	lea    0x12(%r12),%rdi
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2e:	48 89 fa             	mov    %rdi,%rdx
  31:	83 e2 07             	and    $0x7,%edx
  34:	38 d0                	cmp    %dl,%al
  36:	7f 08                	jg     0x40
  38:	84 c0                	test   %al,%al
  3a:	0f 85 76 03 00 00    	jne    0x3b6