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BUG: KASAN: slab-out-of-bounds in hiddev_ioctl_usage.isra.0+0x126d/0x13f0 drivers/hid/usbhid/hiddev.c:528
Write of size 4 at addr ffff8881a8ac8080 by task syz-executor.5/5252

CPU: 0 PID: 5252 Comm: syz-executor.5 Not tainted 5.9.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xf6/0x16e lib/dump_stack.c:118
 print_address_description.constprop.0+0x1c/0x210 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x37/0x7c mm/kasan/report.c:530
 hiddev_ioctl_usage.isra.0+0x126d/0x13f0 drivers/hid/usbhid/hiddev.c:528
 hiddev_ioctl+0x7a3/0x1570 drivers/hid/usbhid/hiddev.c:794
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d579
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc2cf4dfc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000f9c0 RCX: 000000000045d579
RDX: 0000000020000880 RSI: 000000004018480c RDI: 0000000000000007
RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffeadb7952f R14: 00007fc2cf4e09c0 R15: 000000000118cf4c

The buggy address belongs to the page:
page:00000000d5d63b71 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1a8a80
head:00000000d5d63b71 order:7 compound_mapcount:0 compound_pincount:0
flags: 0x200000000010000(head)
raw: 0200000000010000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881a8ac7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881a8ac8000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fe fe
>ffff8881a8ac8080: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
                   ^
 ffff8881a8ac8100: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 ffff8881a8ac8180: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
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