memory leak in fbcon_set

memory leak in fbcon_set_font
Status: upstream: reported C repro on 2021/01/13 10:38
Reported-by: syzbot+2f2c18881a450f22d1bf@syzkaller.appspotmail.com
First crash: 278d, last: 278d
Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2021/03/24 23:42	15m	phil@philpotter.co.uk		upstream	OK
Sample crash report:
BUG: memory leak
unreferenced object 0xffff88811813ea00 (size 512):
  comm "syz-executor939", pid 10246, jiffies 4294971847 (age 34.510s)
  hex dump (first 32 bytes):
    b0 55 1f 9b 00 00 00 00 00 01 00 00 06 00 00 00  .U..............
    11 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000062fad90>] kmalloc include/linux/slab.h:557 [inline]
    [<00000000062fad90>] fbcon_set_font+0x128/0x370 drivers/video/fbdev/core/fbcon.c:2454
    [<00000000ed2d1b1e>] con_font_set drivers/tty/vt/vt.c:4667 [inline]
    [<00000000ed2d1b1e>] con_font_op+0x497/0x740 drivers/tty/vt/vt.c:4711
    [<00000000fd6b18ad>] vt_io_ioctl drivers/tty/vt/vt_ioctl.c:596 [inline]
    [<00000000fd6b18ad>] vt_ioctl+0xeab/0x19d0 drivers/tty/vt/vt_ioctl.c:817
    [<00000000369331c6>] tty_ioctl+0x6c3/0xc40 drivers/tty/tty_io.c:2658
    [<00000000a092c047>] vfs_ioctl fs/ioctl.c:48 [inline]
    [<00000000a092c047>] __do_sys_ioctl fs/ioctl.c:753 [inline]
    [<00000000a092c047>] __se_sys_ioctl fs/ioctl.c:739 [inline]
    [<00000000a092c047>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:739
    [<00000000705a3959>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<00000000f35163f9>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811813ea00 (size 512):
  comm "syz-executor939", pid 10246, jiffies 4294971847 (age 36.030s)
  hex dump (first 32 bytes):
    b0 55 1f 9b 00 00 00 00 00 01 00 00 06 00 00 00  .U..............
    11 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000062fad90>] kmalloc include/linux/slab.h:557 [inline]
    [<00000000062fad90>] fbcon_set_font+0x128/0x370 drivers/video/fbdev/core/fbcon.c:2454
    [<00000000ed2d1b1e>] con_font_set drivers/tty/vt/vt.c:4667 [inline]
    [<00000000ed2d1b1e>] con_font_op+0x497/0x740 drivers/tty/vt/vt.c:4711
    [<00000000fd6b18ad>] vt_io_ioctl drivers/tty/vt/vt_ioctl.c:596 [inline]
    [<00000000fd6b18ad>] vt_ioctl+0xeab/0x19d0 drivers/tty/vt/vt_ioctl.c:817
    [<00000000369331c6>] tty_ioctl+0x6c3/0xc40 drivers/tty/tty_io.c:2658
    [<00000000a092c047>] vfs_ioctl fs/ioctl.c:48 [inline]
    [<00000000a092c047>] __do_sys_ioctl fs/ioctl.c:753 [inline]
    [<00000000a092c047>] __se_sys_ioctl fs/ioctl.c:739 [inline]
    [<00000000a092c047>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:739
    [<00000000705a3959>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<00000000f35163f9>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811813ea00 (size 512):
  comm "syz-executor939", pid 10246, jiffies 4294971847 (age 37.550s)
  hex dump (first 32 bytes):
    b0 55 1f 9b 00 00 00 00 00 01 00 00 06 00 00 00  .U..............
    11 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000062fad90>] kmalloc include/linux/slab.h:557 [inline]
    [<00000000062fad90>] fbcon_set_font+0x128/0x370 drivers/video/fbdev/core/fbcon.c:2454
    [<00000000ed2d1b1e>] con_font_set drivers/tty/vt/vt.c:4667 [inline]
    [<00000000ed2d1b1e>] con_font_op+0x497/0x740 drivers/tty/vt/vt.c:4711
    [<00000000fd6b18ad>] vt_io_ioctl drivers/tty/vt/vt_ioctl.c:596 [inline]
    [<00000000fd6b18ad>] vt_ioctl+0xeab/0x19d0 drivers/tty/vt/vt_ioctl.c:817
    [<00000000369331c6>] tty_ioctl+0x6c3/0xc40 drivers/tty/tty_io.c:2658
    [<00000000a092c047>] vfs_ioctl fs/ioctl.c:48 [inline]
    [<00000000a092c047>] __do_sys_ioctl fs/ioctl.c:753 [inline]
    [<00000000a092c047>] __se_sys_ioctl fs/ioctl.c:739 [inline]
    [<00000000a092c047>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:739
    [<00000000705a3959>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<00000000f35163f9>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811813ea00 (size 512):
  comm "syz-executor939", pid 10246, jiffies 4294971847 (age 37.630s)
  hex dump (first 32 bytes):
    b0 55 1f 9b 00 00 00 00 00 01 00 00 06 00 00 00  .U..............
    11 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000062fad90>] kmalloc include/linux/slab.h:557 [inline]
    [<00000000062fad90>] fbcon_set_font+0x128/0x370 drivers/video/fbdev/core/fbcon.c:2454
    [<00000000ed2d1b1e>] con_font_set drivers/tty/vt/vt.c:4667 [inline]
    [<00000000ed2d1b1e>] con_font_op+0x497/0x740 drivers/tty/vt/vt.c:4711
    [<00000000fd6b18ad>] vt_io_ioctl drivers/tty/vt/vt_ioctl.c:596 [inline]
    [<00000000fd6b18ad>] vt_ioctl+0xeab/0x19d0 drivers/tty/vt/vt_ioctl.c:817
    [<00000000369331c6>] tty_ioctl+0x6c3/0xc40 drivers/tty/tty_io.c:2658
    [<00000000a092c047>] vfs_ioctl fs/ioctl.c:48 [inline]
    [<00000000a092c047>] __do_sys_ioctl fs/ioctl.c:753 [inline]
    [<00000000a092c047>] __se_sys_ioctl fs/ioctl.c:739 [inline]
    [<00000000a092c047>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:739
    [<00000000705a3959>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<00000000f35163f9>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811813ea00 (size 512):
  comm "syz-executor939", pid 10246, jiffies 4294971847 (age 37.720s)
  hex dump (first 32 bytes):
    b0 55 1f 9b 00 00 00 00 00 01 00 00 06 00 00 00  .U..............
    11 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000062fad90>] kmalloc include/linux/slab.h:557 [inline]
    [<00000000062fad90>] fbcon_set_font+0x128/0x370 drivers/video/fbdev/core/fbcon.c:2454
    [<00000000ed2d1b1e>] con_font_set drivers/tty/vt/vt.c:4667 [inline]
    [<00000000ed2d1b1e>] con_font_op+0x497/0x740 drivers/tty/vt/vt.c:4711
    [<00000000fd6b18ad>] vt_io_ioctl drivers/tty/vt/vt_ioctl.c:596 [inline]
    [<00000000fd6b18ad>] vt_ioctl+0xeab/0x19d0 drivers/tty/vt/vt_ioctl.c:817
    [<00000000369331c6>] tty_ioctl+0x6c3/0xc40 drivers/tty/tty_io.c:2658
    [<00000000a092c047>] vfs_ioctl fs/ioctl.c:48 [inline]
    [<00000000a092c047>] __do_sys_ioctl fs/ioctl.c:753 [inline]
    [<00000000a092c047>] __se_sys_ioctl fs/ioctl.c:739 [inline]
    [<00000000a092c047>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:739
    [<00000000705a3959>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<00000000f35163f9>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811813ea00 (size 512):
  comm "syz-executor939", pid 10246, jiffies 4294971847 (age 37.810s)
  hex dump (first 32 bytes):
    b0 55 1f 9b 00 00 00 00 00 01 00 00 06 00 00 00  .U..............
    11 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000062fad90>] kmalloc include/linux/slab.h:557 [inline]
    [<00000000062fad90>] fbcon_set_font+0x128/0x370 drivers/video/fbdev/core/fbcon.c:2454
    [<00000000ed2d1b1e>] con_font_set drivers/tty/vt/vt.c:4667 [inline]
    [<00000000ed2d1b1e>] con_font_op+0x497/0x740 drivers/tty/vt/vt.c:4711
    [<00000000fd6b18ad>] vt_io_ioctl drivers/tty/vt/vt_ioctl.c:596 [inline]
    [<00000000fd6b18ad>] vt_ioctl+0xeab/0x19d0 drivers/tty/vt/vt_ioctl.c:817
    [<00000000369331c6>] tty_ioctl+0x6c3/0xc40 drivers/tty/tty_io.c:2658
    [<00000000a092c047>] vfs_ioctl fs/ioctl.c:48 [inline]
    [<00000000a092c047>] __do_sys_ioctl fs/ioctl.c:753 [inline]
    [<00000000a092c047>] __se_sys_ioctl fs/ioctl.c:739 [inline]
    [<00000000a092c047>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:739
    [<00000000705a3959>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<00000000f35163f9>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

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
executing program
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
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
executing program
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
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
Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-gce-leak	2021/01/13 08:51	upstream	e609571b5ffa	0cdd6185	.config	log	report	syz	C