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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 ffff88808b2194cc by task syz-executor.2/23700

CPU: 0 PID: 23700 Comm: syz-executor.2 Not tainted 4.14.190-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:1301
 do_update_region+0x34b/0x5b0 drivers/tty/vt/vt.c:373
 redraw_screen+0x56e/0x790 drivers/tty/vt/vt.c:705
 vc_do_resize+0xc20/0xe30 drivers/tty/vt/vt.c:973
 vt_ioctl+0x19f7/0x1ea0 drivers/tty/vt/vt_ioctl.c:901
 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
RIP: 0033:0x45c369
RSP: 002b:00007f08c4c14c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000001ba00 RCX: 000000000045c369
RDX: 0000000020000580 RSI: 000000000000560a RDI: 0000000000000003
RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffce2581a3f R14: 00007f08c4c159c0 R15: 000000000078bf0c

Allocated by task 20985:
 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:2621
 con_font_set drivers/tty/vt/vt.c:4189 [inline]
 con_font_op+0xb69/0xf60 drivers/tty/vt/vt.c:4254
 vt_ioctl+0xd91/0x1ea0 drivers/tty/vt/vt_ioctl.c:928
 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 0:
 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
 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1446 [inline]
 sctp_chunk_put+0x167/0x250 net/sctp/sm_make_chunk.c:1473
 sctp_packet_pack net/sctp/output.c:485 [inline]
 sctp_packet_transmit+0xff6/0x2d40 net/sctp/output.c:605
 sctp_outq_flush+0xc59/0x2e00 net/sctp/outqueue.c:1187
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1787 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1179 [inline]
 sctp_do_sm+0x400/0x48a0 net/sctp/sm_sideeffect.c:1150
 sctp_generate_heartbeat_event+0x1da/0x3f0 net/sctp/sm_sideeffect.c:391
 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279
 expire_timers+0x232/0x4d0 kernel/time/timer.c:1318
 __run_timers kernel/time/timer.c:1636 [inline]
 run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1649
 __do_softirq+0x254/0xa1d kernel/softirq.c:288

The buggy address belongs to the object at ffff88808b2192c0
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 12 bytes to the right of
 512-byte region [ffff88808b2192c0, ffff88808b2194c0)
The buggy address belongs to the page:
page:ffffea00022c8640 count:1 mapcount:0 mapping:ffff88808b219040 index:0xffff88808b219cc0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88808b219040 ffff88808b219cc0 0000000100000005
raw: ffffea00023df6e0 ffffea00020c0560 ffff88812fe54940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808b219380: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
 ffff88808b219400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808b219480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                              ^
 ffff88808b219500: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff88808b219580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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