Oops: general protection fault, probably for non-canonical address 0xdffffc0000000017: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000000b8-0x00000000000000bf]
CPU: 0 UID: 0 PID: 6127 Comm: syz.3.92 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
CPU: 0 UID: 0 PID: 6127 Comm: syz.3.92 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:iommufd_ioas_change_process+0x60f/0x1580 drivers/iommu/iommufd/ioas.c:538
Code: 00 00 00 4c 8d 73 68 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 7e a1 cd fc 4d 8b 36 4d 01 e6 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 75 3a 45 8b 36 bf 01 00 00 00 44 89 f6 e8 e8
RSP: 0018:ffffc90005f97b00 EFLAGS: 00010206
RAX: 0000000000000017 RBX: ffff88805cfbb800 RCX: 0000000000080000
RDX: ffffc9000f4f1000 RSI: 000000000000059a RDI: 000000000000059b
RBP: ffffc90005f97d30 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000406 R12: 00000000000000b8
R13: dffffc0000000000 R14: 00000000000000b8 R15: 1ffffffff1f5f3f0
FS:  00007f1eae9d56c0(0000) GS:ffff888125c38000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1eae9d4ff8 CR3: 000000002bffe000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 iommufd_fops_ioctl+0x468/0x600 drivers/iommu/iommufd/main.c:533
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1eb079e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1eae9d5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f1eb0a26090 RCX: 00007f1eb079e0d9
RDX: 0000200000000580 RSI: 0000000000003b92 RDI: 0000000000000003
RBP: 00007f1eb0835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1eb0a26128 R14: 00007f1eb0a26090 R15: 00007fff9e780298
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:iommufd_ioas_change_process+0x60f/0x1580 drivers/iommu/iommufd/ioas.c:538
Code: 00 00 00 4c 8d 73 68 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 7e a1 cd fc 4d 8b 36 4d 01 e6 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 75 3a 45 8b 36 bf 01 00 00 00 44 89 f6 e8 e8
RSP: 0018:ffffc90005f97b00 EFLAGS: 00010206
RAX: 0000000000000017 RBX: ffff88805cfbb800 RCX: 0000000000080000
RDX: ffffc9000f4f1000 RSI: 000000000000059a RDI: 000000000000059b
RBP: ffffc90005f97d30 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000406 R12: 00000000000000b8
R13: dffffc0000000000 R14: 00000000000000b8 R15: 1ffffffff1f5f3f0
FS:  00007f1eae9d56c0(0000) GS:ffff888125d38000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1eae9b3ff8 CR3: 000000002bffe000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 4c 8d 73          	add    %cl,0x73(%rbp,%rcx,4)
   6:	68 4c 89 f0 48       	push   $0x48f0894c
   b:	c1 e8 03             	shr    $0x3,%eax
   e:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  13:	74 08                	je     0x1d
  15:	4c 89 f7             	mov    %r14,%rdi
  18:	e8 7e a1 cd fc       	call   0xfccda19b
  1d:	4d 8b 36             	mov    (%r14),%r14
  20:	4d 01 e6             	add    %r12,%r14
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	75 3a                	jne    0x6d
  33:	45 8b 36             	mov    (%r14),%r14d
  36:	bf 01 00 00 00       	mov    $0x1,%edi
  3b:	44 89 f6             	mov    %r14d,%esi
  3e:	e8                   	.byte 0xe8
  3f:	e8                   	.byte 0xe8