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BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:654 [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+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff88809a26edd0 by task syz-executor.4/28086

CPU: 0 PID: 28086 Comm: syz-executor.4 Not tainted 5.9.0-rc7-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+0x1d6/0x29e lib/dump_stack.c:118
 print_address_description+0x66/0x620 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report+0x132/0x1d0 mm/kasan/report.c:530
 __fb_pad_aligned_buffer include/linux/fb.h:654 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x790/0xaf0 drivers/video/fbdev/core/fbcon.c:1308
 con_flush drivers/tty/vt/vt.c:2575 [inline]
 do_con_write+0x2853/0xd580 drivers/tty/vt/vt.c:2905
 con_write+0x20/0x40 drivers/tty/vt/vt.c:3250
 process_output_block drivers/tty/n_tty.c:595 [inline]
 n_tty_write+0xcbf/0x1170 drivers/tty/n_tty.c:2333
 do_tty_write drivers/tty/tty_io.c:962 [inline]
 tty_write+0x593/0x940 drivers/tty/tty_io.c:1046
 vfs_write+0x2d3/0xd10 fs/read_write.c:584
 ksys_write+0x11b/0x220 fs/read_write.c:639
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: 0d b4 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f88bce3ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000039640 RCX: 000000000045dd99
RDX: 0000000000000040 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007fffe7d11a5f R14: 00007f88bce3f9c0 R15: 000000000118bf2c

Allocated by task 20371:
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461
 __do_kmalloc mm/slab.c:3659 [inline]
 __kmalloc+0x205/0x300 mm/slab.c:3668
 kmalloc include/linux/slab.h:559 [inline]
 fbcon_set_font+0x2c4/0x970 drivers/video/fbdev/core/fbcon.c:2496
 con_font_set drivers/tty/vt/vt.c:4663 [inline]
 con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4728
 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:506 [inline]
 vt_ioctl+0xd7f/0x3d70 drivers/tty/vt/vt_ioctl.c:856
 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88809a26ec00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 464 bytes inside of
 512-byte region [ffff88809a26ec00, ffff88809a26ee00)
The buggy address belongs to the page:
page:0000000002680ce3 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9a26e
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002451948 ffffea0002236008 ffff8880aa440600
raw: 0000000000000000 ffff88809a26e000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809a26ec80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88809a26ed00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88809a26ed80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                 ^
 ffff88809a26ee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809a26ee80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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