================================================================== BUG: KASAN: use-after-free in __fb_pad_aligned_buffer include/linux/fb.h:654 [inline] BUG: KASAN: use-after-free in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] BUG: KASAN: use-after-free in bit_putcs+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff888091114183 by task syz-executor.0/31085 CPU: 1 PID: 31085 Comm: syz-executor.0 Not tainted 5.9.0-rc4-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:1362 con_flush drivers/tty/vt/vt.c:2575 [inline] vc_con_write_normal drivers/tty/vt/vt.c:2803 [inline] do_con_write+0x115b/0xd580 drivers/tty/vt/vt.c:2910 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:576 ksys_write+0x11b/0x220 fs/read_write.c:631 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5b9 Code: 5d 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0c4c296c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000038900 RCX: 000000000045d5b9 RDX: 00000000000001b7 RSI: 0000000020001040 RDI: 0000000000000004 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffeb28b8f0f R14: 00007f0c4c2979c0 R15: 000000000118cf4c The buggy address belongs to the page: page:00000000793db522 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x91114 flags: 0xfffe0000000000() raw: 00fffe0000000000 ffffea00012d9f88 ffffea0001d12308 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffff7f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888091114080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888091114100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888091114180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888091114200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888091114280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================