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BUG: KASAN: stack-out-of-bounds in fast_imageblit drivers/video/fbdev/core/sysimgblt.c:262 [inline]
BUG: KASAN: stack-out-of-bounds in sys_imageblit+0x1d95/0x21d0 drivers/video/fbdev/core/sysimgblt.c:326
Write of size 4 at addr ffffc9000523fca0 by task syz.6.1510/10789

CPU: 2 UID: 0 PID: 10789 Comm: syz.6.1510 Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 fast_imageblit drivers/video/fbdev/core/sysimgblt.c:262 [inline]
 sys_imageblit+0x1d95/0x21d0 drivers/video/fbdev/core/sysimgblt.c:326
 drm_fbdev_shmem_defio_imageblit+0x20/0x130 drivers/gpu/drm/drm_fbdev_shmem.c:37
 bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline]
 bit_putcs+0x90e/0xdf0 drivers/video/fbdev/core/bitblit.c:188
 fbcon_putcs+0x364/0x480 drivers/video/fbdev/core/fbcon.c:1308
 do_update_region+0x2e6/0x3f0 drivers/tty/vt/vt.c:619
 invert_screen+0x1da/0x570 drivers/tty/vt/vt.c:740
 highlight drivers/tty/vt/selection.c:57 [inline]
 clear_selection drivers/tty/vt/selection.c:87 [inline]
 clear_selection+0x59/0x70 drivers/tty/vt/selection.c:83
 vc_do_resize+0xda1/0x10f0 drivers/tty/vt/vt.c:1187
 vc_resize include/linux/vt_kern.h:49 [inline]
 fbcon_set_disp+0x7a5/0xe00 drivers/video/fbdev/core/fbcon.c:1409
 con2fb_init_display drivers/video/fbdev/core/fbcon.c:812 [inline]
 set_con2fb_map+0x6fd/0x1060 drivers/video/fbdev/core/fbcon.c:885
 fbcon_set_con2fb_map_ioctl+0x16d/0x220 drivers/video/fbdev/core/fbcon.c:3112
 do_fb_ioctl+0x32a/0x7d0 drivers/video/fbdev/core/fb_chrdev.c:138
 fb_ioctl+0xe5/0x150 drivers/video/fbdev/core/fb_chrdev.c:169
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl fs/ioctl.c:892 [inline]
 __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2189585d29
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:00007f218a35c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2189775fa0 RCX: 00007f2189585d29
RDX: 0000000020000140 RSI: 0000000000004610 RDI: 000000000000000a
RBP: 00007f2189601b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2189775fa0 R15: 00007ffd489e0908
 </TASK>

The buggy address belongs to the virtual mapping at
 [ffffc90005238000, ffffc90005241000) created by:
 kernel_clone+0xfd/0x960 kernel/fork.c:2806

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x235eb
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_ZERO), pid 39, tgid 39 (kworker/u32:2), ts 6116589842, free_ts 5988210129
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1558
 prep_new_page mm/page_alloc.c:1566 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x223/0x25b0 mm/page_alloc.c:4753
 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2269
 vm_area_alloc_pages mm/vmalloc.c:3591 [inline]
 __vmalloc_area_node mm/vmalloc.c:3669 [inline]
 __vmalloc_node_range_noprof+0x724/0x1530 mm/vmalloc.c:3846
 alloc_thread_stack_node kernel/fork.c:314 [inline]
 dup_task_struct kernel/fork.c:1116 [inline]
 copy_process+0x2f06/0x8e50 kernel/fork.c:2224
 kernel_clone+0xfd/0x960 kernel/fork.c:2806
 user_mode_thread+0xb4/0xf0 kernel/fork.c:2884
 call_usermodehelper_exec_work kernel/umh.c:171 [inline]
 call_usermodehelper_exec_work+0xcb/0x170 kernel/umh.c:157
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 66 tgid 66 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0x661/0x1080 mm/page_alloc.c:2659
 vfree+0x174/0x950 mm/vmalloc.c:3383
 delayed_vfree_work+0x56/0x70 mm/vmalloc.c:3303
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffffc9000523fb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000523fc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000523fc80: 00 00 00 00 f1 f1 f1 f1 f1 f1 04 f2 00 00 f2 f2
                               ^
 ffffc9000523fd00: 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00
 ffffc9000523fd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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