netlink: 16 bytes leftover after parsing attributes in process `syz.5.2981'.
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BUG: KASAN: vmalloc-out-of-bounds in fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline]
BUG: KASAN: vmalloc-out-of-bounds in bitfill drivers/video/fbdev/core/fb_fillrect.h:133 [inline]
BUG: KASAN: vmalloc-out-of-bounds in fb_fillrect_static drivers/video/fbdev/core/fb_fillrect.h:219 [inline]
BUG: KASAN: vmalloc-out-of-bounds in fb_fillrect drivers/video/fbdev/core/fb_fillrect.h:278 [inline]
BUG: KASAN: vmalloc-out-of-bounds in sys_fillrect+0x15d4/0x17b0 drivers/video/fbdev/core/sysfillrect.c:24
Write of size 8 at addr ffffc900052e9000 by task syz.5.2981/16397

CPU: 0 UID: 0 PID: 16397 Comm: syz.5.2981 Not tainted syzkaller #0 PREEMPT(full) 
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+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline]
 bitfill drivers/video/fbdev/core/fb_fillrect.h:133 [inline]
 fb_fillrect_static drivers/video/fbdev/core/fb_fillrect.h:219 [inline]
 fb_fillrect drivers/video/fbdev/core/fb_fillrect.h:278 [inline]
 sys_fillrect+0x15d4/0x17b0 drivers/video/fbdev/core/sysfillrect.c:24
 drm_fbdev_shmem_defio_fillrect+0x22/0x140 drivers/gpu/drm/drm_fbdev_shmem.c:38
 bit_clear_margins+0x2f7/0x4c0 drivers/video/fbdev/core/bitblit.c:256
 fbcon_clear_margins.constprop.0+0x1d3/0x240 drivers/video/fbdev/core/fbcon.c:1333
 fbcon_switch+0xa01/0x1420 drivers/video/fbdev/core/fbcon.c:2205
 redraw_screen+0x2c1/0x760 drivers/tty/vt/vt.c:966
 fbcon_blank+0x652/0xc80 drivers/video/fbdev/core/fbcon.c:2266
 do_unblank_screen+0x2c9/0x560 drivers/tty/vt/vt.c:4683
 vt_kdsetmode drivers/tty/vt/vt_ioctl.c:276 [inline]
 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:381 [inline]
 vt_ioctl+0x1229/0x30a0 drivers/tty/vt/vt_ioctl.c:743
 tty_ioctl+0x661/0x1680 drivers/tty/tty_io.c:2792
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc9f378f7c9
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:00007fc9f46b4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc9f39e5fa0 RCX: 00007fc9f378f7c9
RDX: 0000000000000002 RSI: 0000000000004b3a RDI: 0000000000000003
RBP: 00007fc9f3813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc9f39e6038 R14: 00007fc9f39e5fa0 R15: 00007ffd49f63248
 </TASK>

The buggy address belongs to a 0-page vmalloc region starting at 0xffffc90004fe9000 allocated at drm_gem_shmem_vmap_locked+0x561/0x7e0 drivers/gpu/drm/drm_gem_shmem_helper.c:371
Memory state around the buggy address:
 ffffc900052e8f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900052e8f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900052e9000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                   ^
 ffffc900052e9080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc900052e9100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
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