linux-kernel - [syzbot] memory leak in fbcon_set

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Message-ID: <000000000000e2efc305ef0d341f@google.com>
Date:   Sun, 04 Dec 2022 20:34:44 -0800
From:   syzbot <syzbot+25bdb7b1703639abd498@...kaller.appspotmail.com>
To:     daniel@...ll.ch, deller@....de, dri-devel@...ts.freedesktop.org,
        geert+renesas@...der.be, linux-fbdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, sam@...nborg.org,
        syzkaller-bugs@...glegroups.com, tzimmermann@...e.de
Subject: [syzbot] memory leak in fbcon_set_font (2)

Hello,

syzbot found the following issue on:

HEAD commit:    c2bf05db6c78 Merge tag 'i2c-for-6.1-rc8' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=171883d5880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=979161df0e247659
dashboard link: https://syzkaller.appspot.com/bug?extid=25bdb7b1703639abd498
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=14fff84d880000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=135806a7880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63cd45bf1d68/disk-c2bf05db.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bafbfb42c660/vmlinux-c2bf05db.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9f803a721cfc/bzImage-c2bf05db.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+25bdb7b1703639abd498@...kaller.appspotmail.com

BUG: memory leak
unreferenced object 0xffff888111648000 (size 18448):
  comm "syz-executor148", pid 3653, jiffies 4294970435 (age 13.520s)
  hex dump (first 32 bytes):
    85 44 7e c7 00 00 00 00 00 48 00 00 00 00 00 00  .D~......H......
    92 30 86 d2 8c 38 30 9e e7 a3 05 00 9f 09 33 bb  .0...80.......3.
  backtrace:
    [<ffffffff814ee6d3>] __do_kmalloc_node mm/slab_common.c:943 [inline]
    [<ffffffff814ee6d3>] __kmalloc+0xb3/0x120 mm/slab_common.c:968
    [<ffffffff8250c359>] kmalloc include/linux/slab.h:558 [inline]
    [<ffffffff8250c359>] fbcon_set_font+0x1a9/0x470 drivers/video/fbdev/core/fbcon.c:2508
    [<ffffffff8262cd59>] con_font_set drivers/tty/vt/vt.c:4667 [inline]
    [<ffffffff8262cd59>] con_font_op+0x3a9/0x600 drivers/tty/vt/vt.c:4713
    [<ffffffff82618e3d>] vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
    [<ffffffff82618e3d>] vt_ioctl+0x14fd/0x1a80 drivers/tty/vt/vt_ioctl.c:752
    [<ffffffff825fdaf5>] tty_ioctl+0x6d5/0xbe0 drivers/tty/tty_io.c:2771
    [<ffffffff816200bc>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff816200bc>] __do_sys_ioctl fs/ioctl.c:870 [inline]
    [<ffffffff816200bc>] __se_sys_ioctl fs/ioctl.c:856 [inline]
    [<ffffffff816200bc>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:856
    [<ffffffff8485c5e5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff8485c5e5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84a00087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

BUG: memory leak
unreferenced object 0xffff888110b18000 (size 18448):
  comm "syz-executor148", pid 3655, jiffies 4294971001 (age 7.860s)
  hex dump (first 32 bytes):
    85 44 7e c7 00 00 00 00 00 48 00 00 00 00 00 00  .D~......H......
    92 30 86 d2 8c 38 30 9e e7 a3 05 00 9f 09 33 bb  .0...80.......3.
  backtrace:
    [<ffffffff814ee6d3>] __do_kmalloc_node mm/slab_common.c:943 [inline]
    [<ffffffff814ee6d3>] __kmalloc+0xb3/0x120 mm/slab_common.c:968
    [<ffffffff8250c359>] kmalloc include/linux/slab.h:558 [inline]
    [<ffffffff8250c359>] fbcon_set_font+0x1a9/0x470 drivers/video/fbdev/core/fbcon.c:2508
    [<ffffffff8262cd59>] con_font_set drivers/tty/vt/vt.c:4667 [inline]
    [<ffffffff8262cd59>] con_font_op+0x3a9/0x600 drivers/tty/vt/vt.c:4713
    [<ffffffff82618e3d>] vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
    [<ffffffff82618e3d>] vt_ioctl+0x14fd/0x1a80 drivers/tty/vt/vt_ioctl.c:752
    [<ffffffff825fdaf5>] tty_ioctl+0x6d5/0xbe0 drivers/tty/tty_io.c:2771
    [<ffffffff816200bc>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff816200bc>] __do_sys_ioctl fs/ioctl.c:870 [inline]
    [<ffffffff816200bc>] __se_sys_ioctl fs/ioctl.c:856 [inline]
    [<ffffffff816200bc>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:856
    [<ffffffff8485c5e5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff8485c5e5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84a00087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory
write to /proc/sys/kernel/hung_task_check_interval_secs failed: No such file or directory
write to /proc/sys/kernel/softlockup_all_cpu_backtrace failed: No such file or directory


---
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