================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:663 [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+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff88809b30c3e4 by task agetty/639 CPU: 0 PID: 639 Comm: agetty Not tainted 4.14.215-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load1_noabort+0x68/0x70 mm/kasan/report.c:427 __fb_pad_aligned_buffer include/linux/fb.h:663 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x2fe/0x480 drivers/video/fbdev/core/fbcon.c:1247 con_flush drivers/tty/vt/vt.c:2206 [inline] do_con_write+0xaf6/0x19b0 drivers/tty/vt/vt.c:2456 con_write+0x21/0xa0 drivers/tty/vt/vt.c:2805 process_output_block drivers/tty/n_tty.c:595 [inline] n_tty_write+0x352/0xda0 drivers/tty/n_tty.c:2333 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x410/0x740 drivers/tty/tty_io.c:1043 __vfs_write+0xe4/0x630 fs/read_write.c:480 vfs_write+0x17f/0x4d0 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xf2/0x210 fs/read_write.c:582 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fdb45aba970 RSP: 002b:00007ffebf401488 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fdb45aba970 RDX: 0000000000000001 RSI: 00007fdb45d79683 RDI: 0000000000000001 RBP: 00007fdb45d79683 R08: 00007fdb45d7a760 R09: 00007fdb45f9c500 R10: 0000000000000097 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000001 R14: 00007fdb45d79600 R15: 0000000000000001 Allocated by task 23472: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15a/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] fbcon_set_font+0x2fb/0x7c0 drivers/video/fbdev/core/fbcon.c:2456 con_font_set drivers/tty/vt/vt.c:4190 [inline] con_font_op+0x9e2/0xd90 drivers/tty/vt/vt.c:4234 vt_ioctl+0xd5d/0x1d50 drivers/tty/vt/vt_ioctl.c:938 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 22612: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 skb_free_head net/core/skbuff.c:554 [inline] skb_release_data+0x5f6/0x820 net/core/skbuff.c:574 skb_release_all net/core/skbuff.c:631 [inline] __kfree_skb net/core/skbuff.c:645 [inline] consume_skb+0xe0/0x380 net/core/skbuff.c:705 netlink_unicast_kernel net/netlink/af_netlink.c:1288 [inline] netlink_unicast+0x43f/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff88809b30c280 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 356 bytes inside of 512-byte region [ffff88809b30c280, ffff88809b30c480) The buggy address belongs to the page: page:ffffea00026cc300 count:1 mapcount:0 mapping:ffff88809b30c000 index:0x0 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff88809b30c000 0000000000000000 0000000100000006 raw: ffffea000261e4a0 ffffea00027db420 ffff88813fe80940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809b30c280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88809b30c300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88809b30c380: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88809b30c400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809b30c480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================