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BUG: KASAN: stack-out-of-bounds in ft260_smbus_write+0x156/0x2f0 drivers/hid/hid-ft260.c:486
Read of size 42 at addr ffffc9000400fd21 by task syz.2.19/6689

CPU: 0 UID: 0 PID: 6689 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 ft260_smbus_write+0x156/0x2f0 drivers/hid/hid-ft260.c:486
 ft260_smbus_xfer+0x8bc/0xdd0 drivers/hid/hid-ft260.c:-1
 __i2c_smbus_xfer+0x8d8/0x1e40 drivers/i2c/i2c-core-smbus.c:591
 i2c_smbus_xfer+0x1f4/0x310 drivers/i2c/i2c-core-smbus.c:546
 i2cdev_ioctl_smbus+0x434/0x730 drivers/i2c/i2c-dev.c:389
 i2cdev_ioctl+0x615/0x880 drivers/i2c/i2c-dev.c:478
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2fd499aef9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2fd57c8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2fd4c05fa0 RCX: 00007f2fd499aef9
RDX: 0000200000000200 RSI: 0000000000000720 RDI: 0000000000000004
RBP: 00007f2fd4a2fee0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2fd4c06038 R14: 00007f2fd4c05fa0 R15: 00007ffdd9ef9a18
 </TASK>

The buggy address belongs to stack of task syz.2.19/6689
 and is located at offset 33 in frame:
 i2cdev_ioctl_smbus+0x0/0x730 drivers/i2c/i2c-dev.c:317

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

The buggy address belongs to a vmalloc virtual mapping
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x74b0f
memcg:ffff888030e80302
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff888030e80302
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x29c2(GFP_NOWAIT|__GFP_HIGHMEM|__GFP_IO|__GFP_FS|__GFP_ZERO), pid 6687, tgid 6687 (syz.2.19), ts 136312253250, free_ts 134541265100
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1883
 prep_new_page mm/page_alloc.c:1891 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3956
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5244
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2485
 alloc_frozen_pages_noprof mm/mempolicy.c:2556 [inline]
 alloc_pages_noprof+0xa8/0x190 mm/mempolicy.c:2576
 vm_area_alloc_pages mm/vmalloc.c:3662 [inline]
 __vmalloc_area_node mm/vmalloc.c:3876 [inline]
 __vmalloc_node_range_noprof+0x79b/0x1730 mm/vmalloc.c:4064
 __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4124
 alloc_thread_stack_node kernel/fork.c:355 [inline]
 dup_task_struct+0x228/0x9a0 kernel/fork.c:924
 copy_process+0x508/0x3cf0 kernel/fork.c:2050
 kernel_clone+0x248/0x870 kernel/fork.c:2653
 __do_sys_clone3 kernel/fork.c:2955 [inline]
 __se_sys_clone3+0x33c/0x360 kernel/fork.c:2934
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5181 tgid 5181 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1432 [inline]
 __free_frozen_pages+0xc01/0xd80 mm/page_alloc.c:2972
 __slab_free+0x263/0x2b0 mm/slub.c:5487
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4456 [inline]
 slab_alloc_node mm/slub.c:4785 [inline]
 kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4837
 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:701
 alloc_skb include/linux/skbuff.h:1383 [inline]
 alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6746
 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:2995
 unix_dgram_sendmsg+0x460/0x18e0 net/unix/af_unix.c:2130
 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737
 __sock_sendmsg net/socket.c:752 [inline]
 __sys_sendto+0x3ff/0x590 net/socket.c:2221
 __do_sys_sendto net/socket.c:2228 [inline]
 __se_sys_sendto net/socket.c:2224 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2224
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffffc9000400fc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000400fc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000400fd00: f1 f1 f1 f1 00 00 00 00 02 f3 f3 f3 f3 f3 f3 f3
                                           ^
 ffffc9000400fd80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
 ffffc9000400fe00: f8 f2 f8 f8 f2 f2 00 00 f3 f3 f3 f3 00 00 00 00
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