comedi: runflags cannot determine whether to reclaim chanlist

syzbot reported a memory leak [1], because commit 4e1da516debb ("comedi:
Add reference counting for Comedi command handling") did not consider
the exceptional exit case in do_cmd_ioctl() where runflags is not set.
This caused chanlist not to be properly freed by do_become_nonbusy(),
as it only frees chanlist when runflags is correctly set.

Added a check in do_become_nonbusy() for the case where runflags is not
set, to properly free the chanlist memory.

[1]
BUG: memory leak
  backtrace (crc 844a0efa):
    __comedi_get_user_chanlist drivers/comedi/comedi_fops.c:1815 [inline]
    do_cmd_ioctl.part.0+0x112/0x350 drivers/comedi/comedi_fops.c:1890
    do_cmd_ioctl drivers/comedi/comedi_fops.c:1858 [inline]

Fixes: 4e1da516debb ("comedi: Add reference counting for Comedi command handling")
Reported-by: syzbot+f238baf6ded841b5a82e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f238baf6ded841b5a82e
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Cc: stable <stable@kernel.org> # 6.19
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://patch.msgid.link/20260310111104.70959-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions