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BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:655 [inline]
BUG: KASAN: slab-out-of-bounds in fb_pad_aligned_buffer+0x138/0x160 drivers/video/fbdev/core/fbmem.c:116
Read of size 1 at addr ffff88804f569950 by task syz-executor.0/22101

CPU: 1 PID: 22101 Comm: syz-executor.0 Not tainted 5.6.0-rc2-next-20200220-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:641
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 __fb_pad_aligned_buffer include/linux/fb.h:655 [inline]
 fb_pad_aligned_buffer+0x138/0x160 drivers/video/fbdev/core/fbmem.c:116
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:99 [inline]
 bit_putcs+0xd14/0xf10 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x33c/0x3e0 drivers/video/fbdev/core/fbcon.c:1360
 do_update_region+0x42b/0x6f0 drivers/tty/vt/vt.c:677
 redraw_screen+0x676/0x7d0 drivers/tty/vt/vt.c:1022
 vc_do_resize+0x10c9/0x1460 drivers/tty/vt/vt.c:1295
 vc_resize+0x4d/0x60 drivers/tty/vt/vt.c:1315
 vt_ioctl+0x207b/0x26c0 drivers/tty/vt/vt_ioctl.c:891
 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f03c1dc4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f03c1dc56d4 RCX: 000000000045c449
RDX: 0000000020000080 RSI: 000000000000560a RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000066b R14: 00000000004c8fe0 R15: 000000000076bf2c

Allocated by task 16338:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:515 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x163/0x770 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 fbcon_set_font+0x32d/0x860 drivers/video/fbdev/core/fbcon.c:2670
 con_font_set drivers/tty/vt/vt.c:4549 [inline]
 con_font_op+0xe30/0x1270 drivers/tty/vt/vt.c:4614
 vt_ioctl+0x181a/0x26c0 drivers/tty/vt/vt_ioctl.c:970
 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff88804f568000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 6480 bytes inside of
 8192-byte region [ffff88804f568000, ffff88804f56a000)
The buggy address belongs to the page:
page:ffffea00013d5a00 refcount:1 mapcount:0 mapping:00000000838701d4 index:0x0 head:ffffea00013d5a00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea00013d3108 ffffea000136ff08 ffff8880aa4021c0
raw: 0000000000000000 ffff88804f568000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804f569800: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88804f569880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88804f569900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                 ^
 ffff88804f569980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88804f569a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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