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BUG: KASAN: use-after-free in __fb_pad_aligned_buffer include/linux/fb.h:663 [inline]
BUG: KASAN: use-after-free in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
BUG: KASAN: use-after-free in bit_putcs+0xa8a/0xc00 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff888090045718 by task syz-executor.4/16315

CPU: 0 PID: 16315 Comm: syz-executor.4 Not tainted 4.14.181-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+0x282/0x5b0 drivers/tty/vt/vt.c:363
 redraw_screen+0x562/0x760 drivers/tty/vt/vt.c:705
 vc_do_resize+0xbe0/0xde0 drivers/tty/vt/vt.c:967
 vt_ioctl+0x1a64/0x1f20 drivers/tty/vt/vt_ioctl.c:901
 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: 0033:0x45ca29
RSP: 002b:00007f3b5a6d7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f2b00 RCX: 000000000045ca29
RDX: 00000000200000c0 RSI: 000000000000560a RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000673 R14: 00000000004c9681 R15: 00007f3b5a6d86d4

Allocated by task 16019:
 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_node mm/slab.c:3682 [inline]
 __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3696
 __kmalloc_reserve.isra.0+0x35/0xd0 net/core/skbuff.c:137
 pskb_expand_head+0x115/0xc90 net/core/skbuff.c:1462
 skb_ensure_writable+0x249/0x2e0 net/core/skbuff.c:5091
 __bpf_try_make_writable net/core/filter.c:1403 [inline]
 bpf_try_make_writable net/core/filter.c:1409 [inline]
 bpf_try_make_head_writable net/core/filter.c:1417 [inline]
 ____bpf_clone_redirect net/core/filter.c:1781 [inline]
 bpf_clone_redirect+0x120/0x2c0 net/core/filter.c:1759
 0xffffffffa0090fd5

Freed by task 16019:
 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 net/core/skbuff.c:645 [inline]
 kfree_skb+0xae/0x340 net/core/skbuff.c:663
 vti_xmit net/ipv4/ip_vti.c:307 [inline]
 vti_tunnel_xmit+0x555/0x16f0 net/ipv4/ip_vti.c:339
 __netdev_start_xmit include/linux/netdevice.h:4039 [inline]
 netdev_start_xmit include/linux/netdevice.h:4048 [inline]
 xmit_one net/core/dev.c:3009 [inline]
 dev_hard_start_xmit+0x186/0x880 net/core/dev.c:3025
 __dev_queue_xmit+0x1dce/0x25a0 net/core/dev.c:3525
 __bpf_tx_skb net/core/filter.c:1708 [inline]
 __bpf_redirect_common net/core/filter.c:1747 [inline]
 __bpf_redirect+0x612/0xa30 net/core/filter.c:1754
 ____bpf_clone_redirect net/core/filter.c:1787 [inline]
 bpf_clone_redirect+0x1e0/0x2c0 net/core/filter.c:1759
 0xffffffffa0090fd5

The buggy address belongs to the object at ffff888090045580
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 408 bytes inside of
 512-byte region [ffff888090045580, ffff888090045780)
The buggy address belongs to the page:
page:ffffea0002401140 count:1 mapcount:0 mapping:ffff888090045080 index:0xffff888090045080
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff888090045080 ffff888090045080 0000000100000002
raw: ffffea00027c3560 ffffea000247fe60 ffff8880aa800940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888090045600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888090045680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888090045700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888090045780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888090045800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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