• Masami Hiramatsu's avatar
    kmod: fix resource leak in call_usermodehelper_pipe() · 8767ba27
    Masami Hiramatsu authored
    Fix resource (write-pipe file) leak in call_usermodehelper_pipe().
    When call_usermodehelper_exec() fails, write-pipe file is opened and
    call_usermodehelper_pipe() just returns an error.  Since it is hard for
    caller to determine whether the error occured when opening the pipe or
    executing the helper, the caller cannot close the pipe by themselves.
    I've found this resoruce leak when testing coredump.  You can check how
    the resource leaks as below;
    $ echo "|nocommand" > /proc/sys/kernel/core_pattern
    $ ulimit -c unlimited
    $ while [ 1 ]; do ./segv; done &> /dev/null &
    $ cat /proc/meminfo (<- repeat it)
    where segv.c is;
    int main () {
            char *p = 0;
            *p = 1;
    This patch closes write-pipe file if call_usermodehelper_exec() failed.
    Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
    Cc: Rusty Russell <rusty@rustcorp.com.au>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
kmod.c 14.6 KB