futex_wake_op: syz.1.19 tries to shift op by -1; fix this program
Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4216 Comm: syz.1.19 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 82000405 (Nzcv daif -PAN -UAO +TCO -DIT -SSBS BTYPE=jc)
pc : arch_futex_atomic_op_inuser arch/arm64/include/asm/futex.h:72 [inline]
pc : futex_atomic_op_inuser kernel/futex/core.c:1729 [inline]
pc : futex_wake_op kernel/futex/core.c:1779 [inline]
pc : do_futex+0x7a8/0x257c kernel/futex/core.c:3993
lr : __uaccess_enable_tco arch/arm64/include/asm/uaccess.h:188 [inline]
lr : uaccess_enable_privileged arch/arm64/include/asm/uaccess.h:221 [inline]
lr : arch_futex_atomic_op_inuser arch/arm64/include/asm/futex.h:72 [inline]
lr : futex_atomic_op_inuser kernel/futex/core.c:1729 [inline]
lr : futex_wake_op kernel/futex/core.c:1779 [inline]
lr : do_futex+0x774/0x257c kernel/futex/core.c:3993
sp : ffff80001fd178a0
x29: ffff80001fd17c20 x28: 00000000fffffff2 x27: 00000000c5fffffd
x26: ffff0000d8680000 x25: 0000000000000001 x24: 0000000000000004
x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000000000
x20: 0000000000000000 x19: 1fffe0001b0d02a9 x18: 0000000000000001
x17: 0000000000000002 x16: ffff8000083bf920 x15: 0000000000000004
x14: 0000000000ff0100 x13: ffffffffffffffff x12: 0000000080000000
x11: 00000000fffffff5 x10: 00000000fffffff2 x9 : ffff8000083bf8ec
x8 : 0000000000000080 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff80001fd17198 x4 : ffff80001424f400 x3 : ffff80000a723764
x2 : ffff0001a10e6d50 x1 : ffff80001435cb90 x0 : 0000000000000004
Call trace:
 arch_futex_atomic_op_inuser arch/arm64/include/asm/futex.h:72 [inline]
 futex_atomic_op_inuser kernel/futex/core.c:1729 [inline]
 futex_wake_op kernel/futex/core.c:1779 [inline]
 do_futex+0x7a8/0x257c kernel/futex/core.c:3993
 __do_sys_futex kernel/futex/core.c:4059 [inline]
 __se_sys_futex kernel/futex/core.c:4040 [inline]
 __arm64_sys_futex+0x388/0x400 kernel/futex/core.c:4040
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: 3400009c 4b1c0108 35ffff68 2a0b03fc (d5033bbf) 
---[ end trace 1c57679cb154b499 ]---
----------------
Code disassembly (best guess):
   0:	3400009c 	cbz	w28, 0x10
   4:	4b1c0108 	sub	w8, w8, w28
   8:	35ffff68 	cbnz	w8, 0xfffffffffffffff4
   c:	2a0b03fc 	mov	w28, w11
* 10:	d5033bbf 	dmb	ish <-- trapping instruction