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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+0xa8a/0xc00 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff88805a09ac68 by task syz-executor.4/7713

CPU: 1 PID: 7713 Comm: syz-executor.4 Not tainted 4.14.184-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+0x54/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2b9 mm/kasan/report.c:393
 __fb_pad_aligned_buffer include/linux/fb.h:663 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0xa8a/0xc00 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x3bb/0x480 drivers/video/fbdev/core/fbcon.c:1301
 do_update_region+0x34b/0x5b0 drivers/tty/vt/vt.c:373
 redraw_screen+0x562/0x760 drivers/tty/vt/vt.c:705
 fbcon_blank+0x982/0xd20 drivers/video/fbdev/core/fbcon.c:2373
 do_unblank_screen drivers/tty/vt/vt.c:3929 [inline]
 do_unblank_screen+0x1fd/0x4e0 drivers/tty/vt/vt.c:3896
 unblank_screen drivers/tty/vt/vt.c:3948 [inline]
 tioclinux+0x113/0x400 drivers/tty/vt/vt.c:2711
 vt_ioctl+0x14e8/0x1f20 drivers/tty/vt/vt_ioctl.c:372
 tty_ioctl+0x6c9/0x1220 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 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: 0033:0x45cb19
RSP: 002b:00007fa8e3d02c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004ea180 RCX: 000000000045cb19
RDX: 0000000020000280 RSI: 000000000000541c RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000042e R14: 00000000004c7006 R15: 00007fa8e3d036d4

Allocated by task 11749:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc.part.0+0x4f/0xd0 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+0x2f8/0x7c0 drivers/video/fbdev/core/fbcon.c:2621
 con_font_set drivers/tty/vt/vt.c:4182 [inline]
 con_font_op+0xb73/0xf70 drivers/tty/vt/vt.c:4247
 vt_ioctl+0x736/0x1f20 drivers/tty/vt/vt_ioctl.c:928
 tty_ioctl+0x6c9/0x1220 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 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 10923:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xaf/0x190 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcb/0x260 mm/slab.c:3815
 skb_free_head+0x83/0xa0 net/core/skbuff.c:554
 skb_release_data+0x57e/0x7d0 net/core/skbuff.c:574
 skb_release_all+0x46/0x60 net/core/skbuff.c:631
 __kfree_skb+0x11/0x20 net/core/skbuff.c:645
 tcp_data_queue+0x175e/0x3150 net/ipv4/tcp_input.c:4675
 tcp_rcv_state_process+0xbac/0x494e net/ipv4/tcp_input.c:6157
 tcp_v4_do_rcv+0x2eb/0x800 net/ipv4/tcp_ipv4.c:1489
 sk_backlog_rcv include/net/sock.h:917 [inline]
 __release_sock+0x12a/0x350 net/core/sock.c:2267
 release_sock+0x54/0x1b0 net/core/sock.c:2782
 tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1458
 inet_sendmsg+0x116/0x4d0 net/ipv4/af_inet.c:762
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 SYSC_sendto net/socket.c:1763 [inline]
 SyS_sendto+0x1c7/0x2c0 net/socket.c:1731
 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 ffff88805a09a940
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 808 bytes inside of
 1024-byte region [ffff88805a09a940, ffff88805a09ad40)
The buggy address belongs to the page:
page:ffffea0001682680 count:1 mapcount:0 mapping:ffff88805a09a040 index:0xffff88805a09b6c0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffff88805a09a040 ffff88805a09b6c0 0000000100000004
raw: ffffea0002463820 ffffea00025c7fa0 ffff8880aa800ac0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88805a09ab00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805a09ab80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805a09ac00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                          ^
 ffff88805a09ac80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805a09ad00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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