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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:348 [inline]
BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x28d/0x5b0 drivers/video/fbdev/core/fbcon.c:2446
Read of size 4 at addr ffff8880a4dfab50 by task syz-executor.1/8830

CPU: 1 PID: 8830 Comm: syz-executor.1 Not tainted 4.19.118-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+0x188/0x20d lib/dump_stack.c:118
 print_address_description.cold+0x7c/0x212 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396
 memcpy+0x20/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:348 [inline]
 fbcon_get_font+0x28d/0x5b0 drivers/video/fbdev/core/fbcon.c:2446
 con_font_get drivers/tty/vt/vt.c:4431 [inline]
 con_font_op+0x1f7/0x1130 drivers/tty/vt/vt.c:4590
 vt_ioctl+0xcd0/0x2500 drivers/tty/vt/vt_ioctl.c:928
 tty_ioctl+0x7a1/0x1420 drivers/tty/tty_io.c:2669
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcda/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
RIP: 0033:0x45c829
Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5657083c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e9200 RCX: 000000000045c829
RDX: 0000000020000440 RSI: 0000000000004b60 RDI: 0000000000000004
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000041d R14: 00000000004c6bd1 R15: 00007f56570846d4

Allocated by task 28266:
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531
 __do_kmalloc mm/slab.c:3727 [inline]
 __kmalloc+0x15b/0x770 mm/slab.c:3736
 kmalloc include/linux/slab.h:520 [inline]
 fbcon_set_font+0x331/0x870 drivers/video/fbdev/core/fbcon.c:2644
 con_font_set drivers/tty/vt/vt.c:4523 [inline]
 con_font_op+0xd3e/0x1130 drivers/tty/vt/vt.c:4588
 do_fontx_ioctl drivers/tty/vt/vt_ioctl.c:265 [inline]
 vt_ioctl+0x322/0x2500 drivers/tty/vt/vt_ioctl.c:945
 tty_ioctl+0x7a1/0x1420 drivers/tty/tty_io.c:2669
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcda/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 6421:
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xce/0x220 mm/slab.c:3822
 skb_free_head+0x91/0xb0 net/core/skbuff.c:554
 skb_release_data+0x600/0x8c0 net/core/skbuff.c:574
 skb_release_all+0x46/0x60 net/core/skbuff.c:631
 __kfree_skb+0x11/0x20 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:1751 [inline]
 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3153 [inline]
 tcp_ack+0x1d69/0x4e80 net/ipv4/tcp_input.c:3678
 tcp_rcv_established+0x12cd/0x1e60 net/ipv4/tcp_input.c:5566
 tcp_v4_do_rcv+0x60b/0x8b0 net/ipv4/tcp_ipv4.c:1535
 sk_backlog_rcv include/net/sock.h:946 [inline]
 __release_sock+0x134/0x3a0 net/core/sock.c:2342
 release_sock+0x54/0x1c0 net/core/sock.c:2858
 tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1453
 inet_sendmsg+0x12e/0x590 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:632
 sock_write_iter+0x283/0x3c0 net/socket.c:901
 call_write_iter include/linux/fs.h:1821 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x512/0x760 fs/read_write.c:487
 vfs_write+0x206/0x550 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 ffff8880a4dfa540
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 1552 bytes inside of
 2048-byte region [ffff8880a4dfa540, ffff8880a4dfad40)
The buggy address belongs to the page:
page:ffffea0002937e80 count:1 mapcount:0 mapping:ffff88812c39cc40 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea0002179c88 ffffea000251ba08 ffff88812c39cc40
raw: 0000000000000000 ffff8880a4dfa540 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a4dfaa00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a4dfaa80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880a4dfab00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                 ^
 ffff8880a4dfab80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a4dfac00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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