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BUG: KASAN: vmalloc-out-of-bounds in fast_imageblit drivers/video/fbdev/core/sysimgblt.c:257 [inline]
BUG: KASAN: vmalloc-out-of-bounds in sys_imageblit+0x20bb/0x21d0 drivers/video/fbdev/core/sysimgblt.c:326
Write of size 4 at addr ffffc90005131000 by task syz.4.3916/18961

CPU: 0 UID: 0 PID: 18961 Comm: syz.4.3916 Not tainted 6.14.0-rc7-syzkaller-00205-g586de92313fc #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:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xd9/0x110 mm/kasan/report.c:634
 fast_imageblit drivers/video/fbdev/core/sysimgblt.c:257 [inline]
 sys_imageblit+0x20bb/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
 con_putc+0x143/0x170 drivers/tty/vt/vt.c:302
 complement_pos+0x2d5/0x4f0 drivers/tty/vt/vt.c:757
 highlight_pointer drivers/tty/vt/selection.c:63 [inline]
 clear_selection+0x1b/0x70 drivers/tty/vt/selection.c:85
 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: 0033:0x7fcb95d8d169
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:00007fcb96c5b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcb95fa5fa0 RCX: 00007fcb95d8d169
RDX: 00002000000000c0 RSI: 0000000000004610 RDI: 0000000000000003
RBP: 00007fcb95e0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcb95fa5fa0 R15: 00007ffcf67bcd18
 </TASK>

The buggy address ffffc90005131000 belongs to a vmalloc virtual mapping
Memory state around the buggy address:
 ffffc90005130f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90005130f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc90005131000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                   ^
 ffffc90005131080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90005131100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
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