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BUG: KASAN: slab-out-of-bounds in soft_cursor+0x96b/0xa30 drivers/video/fbdev/core/softcursor.c:61
Read of size 1 at addr ffff88801f0d4110 by task kworker/0:4/9054

CPU: 0 PID: 9054 Comm: kworker/0:4 Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Workqueue: events_power_efficient fb_flashcursor
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fd lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 soft_cursor+0x96b/0xa30 drivers/video/fbdev/core/softcursor.c:61
 bit_cursor+0xcfe/0x1720 drivers/video/fbdev/core/bitblit.c:377
 fb_flashcursor+0x38b/0x430 drivers/video/fbdev/core/fbcon.c:397
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Allocated by task 29732:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 __do_kmalloc mm/slab.c:3659 [inline]
 __kmalloc+0x1b0/0x360 mm/slab.c:3668
 kmalloc include/linux/slab.h:559 [inline]
 fbcon_set_font+0x363/0x9b0 drivers/video/fbdev/core/fbcon.c:2508
 con_font_set drivers/tty/vt/vt.c:4663 [inline]
 con_font_op+0xd26/0x1140 drivers/tty/vt/vt.c:4728
 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:595 [inline]
 vt_ioctl+0x1ce7/0x2e90 drivers/tty/vt/vt_ioctl.c:856
 vt_compat_ioctl+0x168/0x6f0 drivers/tty/vt/vt_ioctl.c:1264
 tty_compat_ioctl+0x19c/0x410 drivers/tty/tty_io.c:2847
 __do_compat_sys_ioctl+0x1d3/0x230 fs/ioctl.c:842
 do_syscall_32_irqs_on arch/x86/entry/common.c:78 [inline]
 __do_fast_syscall_32+0x60/0x90 arch/x86/entry/common.c:137
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:160
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

The buggy address belongs to the object at ffff88801f0d4000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 272 bytes inside of
 512-byte region [ffff88801f0d4000, ffff88801f0d4200)
The buggy address belongs to the page:
page:000000009dd59176 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801f0d4400 pfn:0x1f0d4
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0000a11d08 ffffea000073bb08 ffff88802c840600
raw: ffff88801f0d4400 ffff88801f0d4000 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88801f0d4000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88801f0d4080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88801f0d4100: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff88801f0d4180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801f0d4200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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