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BUG: KASAN: stack-out-of-bounds in cp2112_write_req drivers/hid/hid-cp2112.c:482 [inline]
BUG: KASAN: stack-out-of-bounds in cp2112_xfer+0x60b/0xdd0 drivers/hid/hid-cp2112.c:699
Read of size 42 at addr ffffc900055efd41 by task syz.2.40/4563

CPU: 1 PID: 4563 Comm: syz.2.40 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:420
 kasan_report+0x10b/0x140 mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x27b/0x290 mm/kasan/generic.c:189
 memcpy+0x25/0x60 mm/kasan/shadow.c:65
 cp2112_write_req drivers/hid/hid-cp2112.c:482 [inline]
 cp2112_xfer+0x60b/0xdd0 drivers/hid/hid-cp2112.c:699
 __i2c_smbus_xfer+0x771/0x1fc0 drivers/i2c/i2c-core-smbus.c:590
 i2c_smbus_xfer+0x263/0x3a0 drivers/i2c/i2c-core-smbus.c:545
 i2cdev_ioctl_smbus+0x3e3/0x650 drivers/i2c/i2c-dev.c:381
 i2cdev_ioctl+0x545/0x750 drivers/i2c/i2c-dev.c:467
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdce838f749
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdce9191038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdce85e6180 RCX: 00007fdce838f749
RDX: 0000200000000200 RSI: 0000000000000720 RDI: 0000000000000009
RBP: 00007fdce8413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdce85e6218 R14: 00007fdce85e6180 R15: 00007fff318fec78
 </TASK>

The buggy address belongs to stack of task syz.2.40/4563
 and is located at offset 33 in frame:
 i2cdev_ioctl_smbus+0x0/0x650

This frame has 1 object:
 [32, 66) 'temp'

The buggy address belongs to a 8-page vmalloc region starting at 0xffffc900055e8000 allocated at copy_process+0x5bd/0x4020 kernel/fork.c:2181
The buggy address belongs to the physical page:
page:ffffea0000a5c880 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29722
memcg:ffff8880186ee702
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff8880186ee702
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 4560, tgid 4560 (syz.2.40), ts 90807873141, free_ts 90549408368
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
 vm_area_alloc_pages mm/vmalloc.c:3002 [inline]
 __vmalloc_area_node mm/vmalloc.c:3071 [inline]
 __vmalloc_node_range+0x959/0x1390 mm/vmalloc.c:3243
 alloc_thread_stack_node kernel/fork.c:312 [inline]
 dup_task_struct+0x3d3/0x6b0 kernel/fork.c:989
 copy_process+0x5bd/0x4020 kernel/fork.c:2181
 kernel_clone+0x225/0x8b0 kernel/fork.c:2757
 __do_sys_clone3 kernel/fork.c:3056 [inline]
 __se_sys_clone3+0x2dc/0x360 kernel/fork.c:3040
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare mm/page_alloc.c:1509 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479
 tlb_batch_list_free mm/mmu_gather.c:75 [inline]
 tlb_finish_mmu+0x10c/0x1c0 mm/mmu_gather.c:364
 exit_mmap+0x343/0x8e0 mm/mmap.c:3262
 __mmput+0x118/0x3c0 kernel/fork.c:1200
 exit_mm+0x1e6/0x2c0 kernel/exit.c:565
 do_exit+0x8c1/0x2400 kernel/exit.c:867
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 get_signal+0x1272/0x1350 kernel/signal.c:2871
 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffffc900055efc00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f3 f3 f3
 ffffc900055efc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900055efd00: 00 00 00 00 f1 f1 f1 f1 00 00 00 00 02 f3 f3 f3
                                                       ^
 ffffc900055efd80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900055efe00: f1 f1 f1 f1 04 f2 00 00 f2 f2 00 00 f3 f3 f3 f3
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