================================================================== 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+0xbe2/0xd35 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff888088e15cd0 by task agetty/12293 CPU: 0 PID: 12293 Comm: agetty Not tainted 4.19.150-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+0x22c/0x33e lib/dump_stack.c:118 print_address_description.cold+0x56/0x25c mm/kasan/report.c:256 kasan_report_error.cold+0x66/0xb9 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+0xbe2/0xd35 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x389/0x5d0 drivers/video/fbdev/core/fbcon.c:1269 con_flush drivers/tty/vt/vt.c:2559 [inline] do_con_write+0x7b2/0x1f40 drivers/tty/vt/vt.c:2812 con_put_char+0x96/0xe0 drivers/tty/vt/vt.c:3155 tty_put_char+0xb7/0x150 drivers/tty/tty_io.c:2887 __process_echoes+0x583/0x9f0 drivers/tty/n_tty.c:727 flush_echoes drivers/tty/n_tty.c:827 [inline] __receive_buf drivers/tty/n_tty.c:1646 [inline] n_tty_receive_buf_common+0xbce/0x2a60 drivers/tty/n_tty.c:1740 tiocsti drivers/tty/tty_io.c:2194 [inline] tty_ioctl+0xec4/0x1420 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+0xf9/0x670 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f1c2ec80017 Code: 00 00 00 48 8b 05 81 7e 2b 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 51 7e 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd249b4718 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffd249b4891 RCX: 00007f1c2ec80017 RDX: 00007ffd249b4890 RSI: 0000000000005412 RDI: 0000000000000000 RBP: 00007ffd249b4891 R08: ffffffffffffff98 R09: 00007ffd249b4790 R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffd249b4734 R13: 00007ffd249b4890 R14: 00007ffd249b4790 R15: 0000000000000000 Allocated by task 11887: __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15a/0x4f0 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] fbcon_set_font+0x421/0xc60 drivers/video/fbdev/core/fbcon.c:2467 con_font_set drivers/tty/vt/vt.c:4537 [inline] con_font_op+0xd2b/0x1140 drivers/tty/vt/vt.c:4602 vt_ioctl+0x128c/0x2af0 drivers/tty/vt/vt_ioctl.c:938 tty_ioctl+0x5b0/0x1420 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+0xf9/0x670 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 6520: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x250 mm/slab.c:3822 __rcu_reclaim kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2584 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2864 [inline] rcu_process_callbacks+0x948/0x1d00 kernel/rcu/tree.c:2881 __do_softirq+0x27d/0xad2 kernel/softirq.c:292 The buggy address belongs to the object at ffff888088e154c0 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 16 bytes to the right of 2048-byte region [ffff888088e154c0, ffff888088e15cc0) The buggy address belongs to the page: page:ffffea0002238500 count:1 mapcount:0 mapping:ffff88812c3f6c40 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea0002686e88 ffffea00023ace88 ffff88812c3f6c40 raw: 0000000000000000 ffff888088e143c0 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888088e15b80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff888088e15c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888088e15c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888088e15d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888088e15d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================