Commit 7ff67640 authored Feb 27, 2013 by Oleg Nesterov Committed by Linus Torvalds Feb 27, 2013

usermodehelper: cleanup/fix __orderly_poweroff() && argv_free()



__orderly_poweroff() does argv_free() if call_usermodehelper_fns()
returns -ENOMEM.  As Lucas pointed out, this can be wrong if -ENOMEM was
not triggered by the failing call_usermodehelper_setup(), in this case
both __orderly_poweroff() and argv_cleanup() can do kfree().

Kill argv_cleanup() and change __orderly_poweroff() to call argv_free()
unconditionally like do_coredump() does.  This info->cleanup() is not
needed (and wrong) since 6c0c0d4d "fix bug in orderly_poweroff() which
did the UMH_NO_WAIT => UMH_WAIT_EXEC change, we can rely on the fact
that CLONE_VFORK can't return until do_execve() succeeds/fails.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: hongfeng <hongfeng@marvell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e759a798

kernel/sys.c

+2 −8

Original line number	Original line	Diff line number	Diff line
	@@ -2185,11 +2185,6 @@ SYSCALL_DEFINE3(getcpu, unsigned __user , cpup, unsigned __user , nodep,

	char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";		char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";

	static void argv_cleanup(struct subprocess_info *info)
	{
	argv_free(info->argv);
	}

	static int __orderly_poweroff(void)		static int __orderly_poweroff(void)
	{		{
	int argc;		int argc;
	@@ -2209,8 +2204,7 @@ static int __orderly_poweroff(void)
	}		}

	ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_WAIT_EXEC,		ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_WAIT_EXEC,
	NULL, argv_cleanup, NULL);		NULL, NULL, NULL);
	if (ret == -ENOMEM)
	argv_free(argv);		argv_free(argv);

	return ret;		return ret;