================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:674 [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+0xbaf/0xd10 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff88808adbf62a by task syz-executor.5/16425 CPU: 0 PID: 16425 Comm: syz-executor.5 Not tainted 4.19.131-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+0x1fc/0x2fe lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430 __fb_pad_aligned_buffer include/linux/fb.h:674 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xbaf/0xd10 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x336/0x4f0 drivers/video/fbdev/core/fbcon.c:1323 con_flush drivers/tty/vt/vt.c:2552 [inline] do_con_write+0xd0e/0x1d90 drivers/tty/vt/vt.c:2805 con_put_char+0x96/0xe0 drivers/tty/vt/vt.c:3148 tty_put_char+0xb7/0x150 drivers/tty/tty_io.c:2887 __process_echoes+0x577/0x9f0 drivers/tty/n_tty.c:726 flush_echoes drivers/tty/n_tty.c:827 [inline] __receive_buf drivers/tty/n_tty.c:1646 [inline] n_tty_receive_buf_common+0xc0c/0x2a90 drivers/tty/n_tty.c:1740 tiocsti drivers/tty/tty_io.c:2194 [inline] tty_ioctl+0xff8/0x15c0 drivers/tty/tty_io.c:2580 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45cb29 Code: 0d b7 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1c3285ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004ef020 RCX: 000000000045cb29 RDX: 0000000020000280 RSI: 0000000000005412 RDI: 0000000000000006 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000566 R14: 00000000004c82d4 R15: 00007f1c3285f6d4 Allocated by task 15500: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x3c0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] fbcon_set_font+0x34f/0x8a0 drivers/video/fbdev/core/fbcon.c:2644 con_font_set drivers/tty/vt/vt.c:4529 [inline] con_font_op+0xd02/0x10e0 drivers/tty/vt/vt.c:4594 vt_ioctl+0x116d/0x24d0 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x5b0/0x15c0 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 14667: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 kernfs_fop_release+0x120/0x190 fs/kernfs/file.c:783 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808adbf500 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 298 bytes inside of 512-byte region [ffff88808adbf500, ffff88808adbf700) The buggy address belongs to the page: page:ffffea00022b6fc0 count:1 mapcount:0 mapping:ffff88812c39c940 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffffea00022b6f88 ffffea00022d21c8 ffff88812c39c940 raw: 0000000000000000 ffff88808adbf000 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808adbf500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88808adbf580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88808adbf600: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88808adbf680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808adbf700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================