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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+0x1e04/0x2740 drivers/video/fbdev/core/sysimgblt.c:323
Write of size 4 at addr ffffc90004081000 by task syz-executor.2/22788

CPU: 0 PID: 22788 Comm: syz-executor.2 Not tainted 5.19.0-syzkaller-02972-g200e340f2196 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description+0x65/0x4b0 mm/kasan/report.c:313
 print_report+0xf4/0x210 mm/kasan/report.c:429
 kasan_report+0xfb/0x130 mm/kasan/report.c:491
 fast_imageblit drivers/video/fbdev/core/sysimgblt.c:257 [inline]
 sys_imageblit+0x1e04/0x2740 drivers/video/fbdev/core/sysimgblt.c:323
 drm_fb_helper_sys_imageblit drivers/gpu/drm/drm_fb_helper.c:825 [inline]
 drm_fbdev_fb_imageblit+0x163/0x300 drivers/gpu/drm/drm_fb_helper.c:2328
 bit_putcs+0x19b9/0x1ed0
 fbcon_putcs+0x347/0x520 drivers/video/fbdev/core/fbcon.c:1285
 do_update_region+0x530/0x740 drivers/tty/vt/vt.c:676
 redraw_screen+0x90a/0x1170 drivers/tty/vt/vt.c:1035
 fbcon_do_set_font+0xd86/0x1330 drivers/video/fbdev/core/fbcon.c:2435
 fbcon_set_font+0xc29/0xf70 drivers/video/fbdev/core/fbcon.c:2522
 con_font_set drivers/tty/vt/vt.c:4666 [inline]
 con_font_op+0xbe8/0x1070 drivers/tty/vt/vt.c:4710
 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
 vt_ioctl+0x172e/0x1d00 drivers/tty/vt/vt_ioctl.c:752
 tty_ioctl+0x874/0xc60 drivers/tty/tty_io.c:2778
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f7cc5689209
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7cc677c168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7cc579c030 RCX: 00007f7cc5689209
RDX: 0000000020000040 RSI: 0000000000004b72 RDI: 0000000000000005
RBP: 00007f7cc56e3161 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdd622f60f R14: 00007f7cc677c300 R15: 0000000000022000
 </TASK>

The buggy address belongs to the virtual mapping at
 [ffffc90003d81000, ffffc90004082000) created by:
 drm_gem_shmem_vmap_locked drivers/gpu/drm/drm_gem_shmem_helper.c:319 [inline]
 drm_gem_shmem_vmap+0x391/0x4d0 drivers/gpu/drm/drm_gem_shmem_helper.c:366

Memory state around the buggy address:
 ffffc90004080f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90004080f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90004081000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                   ^
 ffffc90004081080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90004081100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
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