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BUG: KASAN: global-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:641 [inline]
BUG: KASAN: global-out-of-bounds in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:95 [inline]
BUG: KASAN: global-out-of-bounds in bit_putcs+0xa63/0xde0 drivers/video/fbdev/core/bitblit.c:184
Read of size 1 at addr ffffffff8c1876d8 by task syz.8.2679/20857

CPU: 0 UID: 0 PID: 20857 Comm: syz.8.2679 Not tainted 6.16.0-rc5-syzkaller-00038-g733923397fd9 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:408 [inline]
 print_report+0xcd/0x680 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 __fb_pad_aligned_buffer include/linux/fb.h:641 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:95 [inline]
 bit_putcs+0xa63/0xde0 drivers/video/fbdev/core/bitblit.c:184
 fbcon_putcs+0x380/0x4a0 drivers/video/fbdev/core/fbcon.c:1314
 do_update_region+0x1fb/0x3f0 drivers/tty/vt/vt.c:617
 update_region+0xc1/0x160 drivers/tty/vt/vt.c:641
 vcs_write+0x7c7/0xdb0 drivers/tty/vt/vc_screen.c:698
 do_loop_readv_writev fs/read_write.c:850 [inline]
 do_loop_readv_writev fs/read_write.c:835 [inline]
 vfs_writev+0x5dc/0xde0 fs/read_write.c:1059
 do_writev+0x132/0x340 fs/read_write.c:1103
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fba5178e929
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:00007fba52526038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007fba519b5fa0 RCX: 00007fba5178e929
RDX: 0000000000000008 RSI: 0000200000001500 RDI: 0000000000000009
RBP: 00007fba51810b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fba519b5fa0 R15: 00007ffdadb9eb98
 </TASK>

The buggy address belongs to the variable:
 fontdata_8x8+0x878/0x880

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xc187
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea00003061c8 ffffea00003061c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff8c187580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff8c187600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9
>ffffffff8c187680: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
                                                    ^
 ffffffff8c187700: 00 00 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00
 ffffffff8c187780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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