general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 PID: 21644 Comm: syz-executor.4 Not tainted 5.16.0-rc5-next-20211220-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:set_task_ioprio+0x2de/0x620 block/blk-ioc.c:289 Code: 4c 8b ab 18 12 00 00 4d 85 ed 0f 84 9b 01 00 00 e8 b7 fd a4 fd 49 8d 7d 0c 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 ef RSP: 0018:ffffc90006fe7e90 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: ffff88802d3aba80 RCX: ffffc9000a9ca000 RDX: 0000000000000001 RSI: ffffffff83d31899 RDI: 000000000000000c RBP: 0000000000002004 R08: 0000000000000000 R09: ffffffff8ffab957 R10: 0000000000000001 R11: 0000000000000103 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88802d3ac3c8 R15: ffff88802d3acc98 FS: 00007f157f33e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 000000007df5b000 CR4: 00000000003506e0 Call Trace: __do_sys_ioprio_set+0x586/0xae0 block/ioprio.c:124 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: 0033:0x7f15809c8e99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f157f33e168 EFLAGS: 00000246 ORIG_RAX: 00000000000000fb RAX: ffffffffffffffda RBX: 00007f1580adbf60 RCX: 00007f15809c8e99 RDX: 0000000000002004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f1580a22ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc925d857f R14: 00007f157f33e300 R15: 0000000000022000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:set_task_ioprio+0x2de/0x620 block/blk-ioc.c:289 Code: 4c 8b ab 18 12 00 00 4d 85 ed 0f 84 9b 01 00 00 e8 b7 fd a4 fd 49 8d 7d 0c 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 ef RSP: 0018:ffffc90006fe7e90 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: ffff88802d3aba80 RCX: ffffc9000a9ca000 RDX: 0000000000000001 RSI: ffffffff83d31899 RDI: 000000000000000c RBP: 0000000000002004 R08: 0000000000000000 R09: ffffffff8ffab957 R10: 0000000000000001 R11: 0000000000000103 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88802d3ac3c8 R15: ffff88802d3acc98 FS: 00007f157f33e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 000000007df5b000 CR4: 00000000003506e0 ---------------- Code disassembly (best guess): 0: 4c 8b ab 18 12 00 00 mov 0x1218(%rbx),%r13 7: 4d 85 ed test %r13,%r13 a: 0f 84 9b 01 00 00 je 0x1ab 10: e8 b7 fd a4 fd callq 0xfda4fdcc 15: 49 8d 7d 0c lea 0xc(%r13),%rdi 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction 2e: 48 89 f8 mov %rdi,%rax 31: 83 e0 07 and $0x7,%eax 34: 83 c0 01 add $0x1,%eax 37: 38 d0 cmp %dl,%al 39: 7c 08 jl 0x43 3b: 84 d2 test %dl,%dl 3d: 0f .byte 0xf 3e: 85 ef test %ebp,%edi