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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+0xbaf/0xd10 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff88808f9c7683 by task syz-executor.0/29782

CPU: 1 PID: 29782 Comm: syz-executor.0 Not tainted 4.19.139-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+0x1fc/0x2fe lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1c7 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+0xbaf/0xd10 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x336/0x4f0 drivers/video/fbdev/core/fbcon.c:1323
 con_flush drivers/tty/vt/vt.c:2558 [inline]
 do_con_write+0xd0e/0x1d90 drivers/tty/vt/vt.c:2811
 con_write+0x22/0xb0 drivers/tty/vt/vt.c:3144
 process_output_block drivers/tty/n_tty.c:593 [inline]
 n_tty_write+0x3c0/0xff0 drivers/tty/n_tty.c:2331
 do_tty_write drivers/tty/tty_io.c:960 [inline]
 tty_write+0x496/0x810 drivers/tty/tty_io.c:1044
 __vfs_write+0xf7/0x770 fs/read_write.c:485
 __kernel_write+0x109/0x370 fs/read_write.c:506
 write_pipe_buf+0x153/0x1f0 fs/splice.c:798
 splice_from_pipe_feed fs/splice.c:503 [inline]
 __splice_from_pipe+0x389/0x800 fs/splice.c:627
 splice_from_pipe fs/splice.c:662 [inline]
 default_file_splice_write+0xd8/0x180 fs/splice.c:810
 do_splice_from fs/splice.c:852 [inline]
 direct_splice_actor+0x115/0x160 fs/splice.c:1025
 splice_direct_to_actor+0x33f/0x8d0 fs/splice.c:980
 do_splice_direct+0x1a7/0x270 fs/splice.c:1068
 do_sendfile+0x550/0xc30 fs/read_write.c:1447
 __do_sys_sendfile64 fs/read_write.c:1502 [inline]
 __se_sys_sendfile64+0xc4/0x160 fs/read_write.c:1494
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45d249
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f17e8b35c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000026bc0 RCX: 000000000045d249
RDX: 0000000020000040 RSI: 0000000000000003 RDI: 0000000000000007
RBP: 000000000118cf88 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000a808 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007fff348192ff R14: 00007f17e8b369c0 R15: 000000000118cf4c

Allocated by task 23561:
 __do_kmalloc mm/slab.c:3727 [inline]
 __kmalloc+0x15a/0x3c0 mm/slab.c:3736
 kmalloc include/linux/slab.h:520 [inline]
 fbcon_set_font+0x34f/0x8a0 drivers/video/fbdev/core/fbcon.c:2644
 con_font_set drivers/tty/vt/vt.c:4536 [inline]
 con_font_op+0xd02/0x10e0 drivers/tty/vt/vt.c:4601
 vt_ioctl+0x116d/0x24d0 drivers/tty/vt/vt_ioctl.c:928
 tty_ioctl+0x5b0/0x15c0 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+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 19806:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 skb_free_head net/core/skbuff.c:554 [inline]
 skb_release_data+0x6de/0x920 net/core/skbuff.c:574
 skb_release_all net/core/skbuff.c:631 [inline]
 __kfree_skb+0x46/0x60 net/core/skbuff.c:645
 sk_wmem_free_skb include/net/sock.h:1462 [inline]
 tcp_rtx_queue_unlink_and_free include/net/tcp.h:1764 [inline]
 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3154 [inline]
 tcp_ack+0x1d20/0x4fc0 net/ipv4/tcp_input.c:3689
 tcp_rcv_established+0x13b9/0x1e20 net/ipv4/tcp_input.c:5586
 tcp_v4_do_rcv+0x5d6/0x870 net/ipv4/tcp_ipv4.c:1544
 sk_backlog_rcv include/net/sock.h:946 [inline]
 __release_sock+0x134/0x3a0 net/core/sock.c:2344
 release_sock+0x54/0x1b0 net/core/sock.c:2860
 tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1461
 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:632
 sock_write_iter+0x287/0x3c0 net/socket.c:901
 call_write_iter include/linux/fs.h:1821 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x51b/0x770 fs/read_write.c:487
 vfs_write+0x1f3/0x540 fs/read_write.c:549
 ksys_write+0x12b/0x2a0 fs/read_write.c:599
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88808f9c6ec0
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 1987 bytes inside of
 2048-byte region [ffff88808f9c6ec0, ffff88808f9c76c0)
The buggy address belongs to the page:
page:ffffea00023e7180 count:1 mapcount:0 mapping:ffff88812c39cc40 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea0001827e08 ffffea0002a2f008 ffff88812c39cc40
raw: 0000000000000000 ffff88808f9c6640 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808f9c7580: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
 ffff88808f9c7600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808f9c7680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff88808f9c7700: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff88808f9c7780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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