syzbot

general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 3598 Comm: syz-executor439 Not tainted 5.16.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:sg_alloc_append_table_from_pages+0x821/0xdb0 lib/scatterlist.c:525
Code: 0c 24 48 8b 4c 24 48 48 39 c8 48 0f 46 c8 89 f0 4c 8d 3c c7 48 89 4c 24 30 48 b9 00 00 00 00 00 fc ff df 4c 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 24 05 00 00 4d 8b 3f 4c 89 e0 31 ff 83 e0 03 48
RSP: 0018:ffffc90001f5fc48 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000001 RCX: dffffc0000000000
RDX: ffff888018623a00 RSI: 0000000000000000 RDI: 0000000000000010
RBP: 00000000fffff000 R08: fffffffffffff000 R09: ffff888145f2fec0
R10: ffffffff83d8c060 R11: 0000000000000001 R12: 0000000000000002
R13: ffff888145f2fec0 R14: 0000000000000000 R15: 0000000000000010
FS:  0000555556ea9300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020005b4c CR3: 000000006fc91000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 sg_alloc_table_from_pages_segment+0xc9/0x260 lib/scatterlist.c:573
 sg_alloc_table_from_pages include/linux/scatterlist.h:331 [inline]
 get_sg_table.isra.0+0xbb/0x160 drivers/dma-buf/udmabuf.c:67
 begin_cpu_udmabuf+0x130/0x1d0 drivers/dma-buf/udmabuf.c:126
 dma_buf_begin_cpu_access+0xfd/0x1d0 drivers/dma-buf/dma-buf.c:1175
 dma_buf_ioctl+0x29a/0x380 drivers/dma-buf/dma-buf.c:374
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f2e9baf8079
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd94191c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2e9baf8079
RDX: 0000000020000000 RSI: 0000000040086200 RDI: 0000000000000004
RBP: 00007f2e9babc060 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 00007f2e9babc0f0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace fc3b8f1d5f6f9add ]---
RIP: 0010:sg_alloc_append_table_from_pages+0x821/0xdb0 lib/scatterlist.c:525
Code: 0c 24 48 8b 4c 24 48 48 39 c8 48 0f 46 c8 89 f0 4c 8d 3c c7 48 89 4c 24 30 48 b9 00 00 00 00 00 fc ff df 4c 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 24 05 00 00 4d 8b 3f 4c 89 e0 31 ff 83 e0 03 48
RSP: 0018:ffffc90001f5fc48 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 0000000000000001 RCX: dffffc0000000000
RDX: ffff888018623a00 RSI: 0000000000000000 RDI: 0000000000000010
RBP: 00000000fffff000 R08: fffffffffffff000 R09: ffff888145f2fec0
R10: ffffffff83d8c060 R11: 0000000000000001 R12: 0000000000000002
R13: ffff888145f2fec0 R14: 0000000000000000 R15: 0000000000000010
FS:  0000555556ea9300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020005b4c CR3: 000000006fc91000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	0c 24                	or     $0x24,%al
   2:	48 8b 4c 24 48       	mov    0x48(%rsp),%rcx
   7:	48 39 c8             	cmp    %rcx,%rax
   a:	48 0f 46 c8          	cmovbe %rax,%rcx
   e:	89 f0                	mov    %esi,%eax
  10:	4c 8d 3c c7          	lea    (%rdi,%rax,8),%r15
  14:	48 89 4c 24 30       	mov    %rcx,0x30(%rsp)
  19:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  20:	fc ff df
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	0f 85 24 05 00 00    	jne    0x558
  34:	4d 8b 3f             	mov    (%r15),%r15
  37:	4c 89 e0             	mov    %r12,%rax
  3a:	31 ff                	xor    %edi,%edi
  3c:	83 e0 03             	and    $0x3,%eax
  3f:	48                   	rex.W