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BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:663 [inline]
BUG: KASAN: slab-out-of-bounds in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
BUG: KASAN: slab-out-of-bounds in bit_putcs+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff888090a067c2 by task syz-executor.1/17869

CPU: 1 PID: 17869 Comm: syz-executor.1 Not tainted 4.14.191-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load1_noabort+0x68/0x70 mm/kasan/report.c:427
 __fb_pad_aligned_buffer include/linux/fb.h:663 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x2fe/0x480 drivers/video/fbdev/core/fbcon.c:1301
 do_update_region+0x34b/0x5b0 drivers/tty/vt/vt.c:373
 redraw_screen+0x56e/0x790 drivers/tty/vt/vt.c:705
 vc_do_resize+0xc20/0xe30 drivers/tty/vt/vt.c:973
 vt_ioctl+0x19f7/0x1ea0 drivers/tty/vt/vt_ioctl.c:901
 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45ccd9
RSP: 002b:00007fa4f52ecc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000001c300 RCX: 000000000045ccd9
RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003
RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffc7aceb2ef R14: 00007fa4f52ed9c0 R15: 000000000078bf0c

Allocated by task 8645:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15a/0x400 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 fbcon_set_font+0x2fb/0x7c0 drivers/video/fbdev/core/fbcon.c:2621
 con_font_set drivers/tty/vt/vt.c:4189 [inline]
 con_font_op+0xb69/0xf60 drivers/tty/vt/vt.c:4254
 vt_ioctl+0xd91/0x1ea0 drivers/tty/vt/vt_ioctl.c:928
 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 7867:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xc9/0x250 mm/slab.c:3815
 kvfree+0x45/0x50 mm/util.c:416
 __free_fdtable fs/file.c:36 [inline]
 put_files_struct fs/file.c:425 [inline]
 put_files_struct+0x259/0x340 fs/file.c:418
 exit_files+0x7e/0xa0 fs/file.c:450
 do_exit+0x9dc/0x27f0 kernel/exit.c:860
 do_group_exit+0x100/0x2e0 kernel/exit.c:962
 get_signal+0x38d/0x1ca0 kernel/signal.c:2423
 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:814
 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

The buggy address belongs to the object at ffff888090a060c0
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 1794 bytes inside of
 2048-byte region [ffff888090a060c0, ffff888090a068c0)
The buggy address belongs to the page:
page:ffffea0002428180 count:1 mapcount:0 mapping:ffff888090a060c0 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffff888090a060c0 0000000000000000 0000000100000003
raw: ffffea0002846820 ffffea000238c3a0 ffff88812fe52c40 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888090a06680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888090a06700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888090a06780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                           ^
 ffff888090a06800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888090a06880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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