[syzbot] [fbdev?] memory leak in fbcon_set_font (3)

[syzbot <syzbot+6fda7f092994bd03fad1@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    0dd2a6fb1e34 Merge tag 'tty-6.4-rc3' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12f15641280000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8944c5b480b57ee6
dashboard link: https://syzkaller.appspot.com/bug?extid=6fda7f092994bd03fad1
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17c2cf09280000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16325819280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2961112b4460/disk-0dd2a6fb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8ef8e1887351/vmlinux-0dd2a6fb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4a1c984d6f73/bzImage-0dd2a6fb.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6fda7f092994bd03fad1@syzkaller.appspotmail.com

BUG: memory leak
unreferenced object 0xffff88810eb60000 (size 26640):
  comm "syz-executor100", pid 4988, jiffies 4294944215 (age 14.910s)
  hex dump (first 32 bytes):
    03 cc 4b ef 00 00 00 00 00 68 00 00 01 00 00 00  ..K......h......
    0d e4 73 70 56 3e d4 50 e7 4f ba 9e e1 5c c0 c3  ..spV>.P.O...\..
  backtrace:
    [<ffffffff815460d7>] __do_kmalloc_node mm/slab_common.c:954 [inline]
    [<ffffffff815460d7>] __kmalloc+0xb7/0x120 mm/slab_common.c:979
    [<ffffffff826405bd>] kmalloc include/linux/slab.h:563 [inline]
    [<ffffffff826405bd>] fbcon_set_font+0x1ed/0x4a0 drivers/video/fbdev/core/fbcon.c:2502
    [<ffffffff8278ad5e>] con_font_set drivers/tty/vt/vt.c:4626 [inline]
    [<ffffffff8278ad5e>] con_font_op+0x5ae/0x730 drivers/tty/vt/vt.c:4673
    [<ffffffff82774b78>] vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
    [<ffffffff82774b78>] vt_ioctl+0x468/0x1d90 drivers/tty/vt/vt_ioctl.c:752
    [<ffffffff82757161>] tty_ioctl+0x4c1/0xd00 drivers/tty/tty_io.c:2777
    [<ffffffff8167fa80>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff8167fa80>] __do_sys_ioctl fs/ioctl.c:870 [inline]
    [<ffffffff8167fa80>] __se_sys_ioctl fs/ioctl.c:856 [inline]
    [<ffffffff8167fa80>] __x64_sys_ioctl+0x100/0x140 fs/ioctl.c:856
    [<ffffffff84a14749>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff84a14749>] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd



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