=====================================================
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in _inline_copy_to_user include/linux/uaccess.h:196 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xcc/0x120 lib/usercopy.c:26
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 _inline_copy_to_user include/linux/uaccess.h:196 [inline]
 _copy_to_user+0xcc/0x120 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:225 [inline]
 i2cdev_ioctl_smbus+0x586/0x660 drivers/i2c/i2c-dev.c:394
 compat_i2cdev_ioctl+0x48f/0xb40 drivers/i2c/i2c-dev.c:585
 __do_compat_sys_ioctl fs/ioctl.c:1005 [inline]
 __se_compat_sys_ioctl fs/ioctl.c:948 [inline]
 __ia32_compat_sys_ioctl+0x7f9/0x1270 fs/ioctl.c:948
 ia32_sys_call+0x2d07/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:55
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Uninit was stored to memory at:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 9185 at kernel/stacktrace.c:29 stack_trace_print+0xd4/0xf0 kernel/stacktrace.c:29
Modules linked in:
CPU: 0 UID: 0 PID: 9185 Comm: syz.2.1259 Not tainted 6.16.0-rc3-syzkaller-00190-g67a993863163 #0 PREEMPT(undef) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:stack_trace_print+0xd4/0xf0 kernel/stacktrace.c:29
Code: 3c 7d 02 92 89 de ba 20 00 00 00 4c 89 e1 e8 d3 8a 4d ff 49 83 c6 08 49 ff cd 0f 85 6e ff ff ff eb 0b e8 0f aa c3 00 eb d4 90 <0f> 0b 90 5b 41 5c 41 5d 41 5e 41 5f 5d e9 0a 7c f4 0e cc 66 0f 1f
RSP: 0018:ffff888058423818 EFLAGS: 00010246
RAX: ffff8881186dac18 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888058423840 R08: 0000000000000000 R09: 0000000000000000
R10: ffff888057c23858 R11: 0000000000000001 R12: 0000000000000000
R13: 00000000abcd0100 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881aa87d000(0063) knlGS:00000000f511eb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000000c45bc62 CR3: 000000002a898000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kmsan_print_origin+0xb0/0x340 mm/kmsan/report.c:133
 kmsan_report+0x1d3/0x320 mm/kmsan/report.c:196
 kmsan_internal_check_memory+0x1e1/0x230 mm/kmsan/core.c:323
 kmsan_copy_to_user+0xf1/0x190 mm/kmsan/hooks.c:269
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 _inline_copy_to_user include/linux/uaccess.h:196 [inline]
 _copy_to_user+0xcc/0x120 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:225 [inline]
 i2cdev_ioctl_smbus+0x586/0x660 drivers/i2c/i2c-dev.c:394
 compat_i2cdev_ioctl+0x48f/0xb40 drivers/i2c/i2c-dev.c:585
 __do_compat_sys_ioctl fs/ioctl.c:1005 [inline]
 __se_compat_sys_ioctl fs/ioctl.c:948 [inline]
 __ia32_compat_sys_ioctl+0x7f9/0x1270 fs/ioctl.c:948
 ia32_sys_call+0x2d07/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:55
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf712e539
Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f511e55c EFLAGS: 00000206 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000000720
RDX: 0000000080000680 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
---[ end trace 0000000000000000 ]---

Local variable msgbuf1.i created at:
 i2c_smbus_xfer_emulated drivers/i2c/i2c-core-smbus.c:335 [inline]
 __i2c_smbus_xfer+0x86a/0x2f60 drivers/i2c/i2c-core-smbus.c:608
 i2c_smbus_xfer+0x31d/0x4d0 drivers/i2c/i2c-core-smbus.c:546

Bytes 0-1 of 2 are uninitialized
Memory access of size 2 starts at ffff888058423c86
Data copied to user address 0000000080000400

CPU: 0 UID: 0 PID: 9185 Comm: syz.2.1259 Tainted: G        W           6.16.0-rc3-syzkaller-00190-g67a993863163 #0 PREEMPT(undef) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
=====================================================
----------------
Code disassembly (best guess):
   0:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   4:	10 07                	adc    %al,(%rdi)
   6:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   a:	10 08                	adc    %cl,(%rax)
   c:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  20:	00 51 52             	add    %dl,0x52(%rcx)
  23:	55                   	push   %rbp
  24:	89 e5                	mov    %esp,%ebp
  26:	0f 34                	sysenter
  28:	cd 80                	int    $0x80
* 2a:	5d                   	pop    %rbp <-- trapping instruction
  2b:	5a                   	pop    %rdx
  2c:	59                   	pop    %rcx
  2d:	c3                   	ret
  2e:	90                   	nop
  2f:	90                   	nop
  30:	90                   	nop
  31:	90                   	nop
  32:	90                   	nop
  33:	90                   	nop
  34:	90                   	nop
  35:	90                   	nop
  36:	90                   	nop
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop