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BUG: KASAN: vmalloc-out-of-bounds in fast_imageblit drivers/video/fbdev/core/sysimgblt.c:229 [inline]
BUG: KASAN: vmalloc-out-of-bounds in sys_imageblit+0x117f/0x1290 drivers/video/fbdev/core/sysimgblt.c:275
Write of size 4 at addr ffffc9000b901000 by task syz-executor.2/11035

CPU: 2 PID: 11035 Comm: syz-executor.2 Not tainted 5.10.0-rc7-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0x5/0x497 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 fast_imageblit drivers/video/fbdev/core/sysimgblt.c:229 [inline]
 sys_imageblit+0x117f/0x1290 drivers/video/fbdev/core/sysimgblt.c:275
 drm_fb_helper_sys_imageblit+0x1c/0x180 drivers/gpu/drm/drm_fb_helper.c:767
 bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline]
 bit_putcs+0x6e1/0xd20 drivers/video/fbdev/core/bitblit.c:188
 fbcon_putcs+0x35a/0x450 drivers/video/fbdev/core/fbcon.c:1306
 do_update_region+0x399/0x630 drivers/tty/vt/vt.c:676
 redraw_screen+0x658/0x790 drivers/tty/vt/vt.c:1035
 fbcon_blank+0x8c5/0xc30 drivers/video/fbdev/core/fbcon.c:2248
 do_unblank_screen+0x25b/0x470 drivers/tty/vt/vt.c:4406
 vt_kdsetmode drivers/tty/vt/vt_ioctl.c:276 [inline]
 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:381 [inline]
 vt_ioctl+0x1b83/0x2950 drivers/tty/vt/vt_ioctl.c:813
 tty_ioctl+0x1021/0x1600 drivers/tty/tty_io.c:2656
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dcd9
Code: bd b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 8b b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f6bc6567c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045dcd9
RDX: 0000000000000000 RSI: 0000000000004b3a RDI: 0000000000000003
RBP: 00000000004aae00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf40
R13: 00007ffd07fc128f R14: 00007f6bc6548000 R15: 0000000000000003


Memory state around the buggy address:
 ffffc9000b900f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000b900f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000b901000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                   ^
 ffffc9000b901080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc9000b901100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
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