Commit 4188fc31 authored by nir@lichtman.org's avatar nir@lichtman.org Committed by Kees Cook
Browse files

exec: move warning of null argv to be next to the relevant code 



Problem: The warning is currently printed where it is detected that the
arg count is zero but the action is only taken place later in the flow
even though the warning is written as if the action is taken place in
the time of print

This could be problematic since there could be a failure between the
print and the code that takes action which would deem this warning
misleading

Solution: Move the warning print after the action of adding an empty
string as the first argument is successful

Signed-off-by: default avatarNir Lichtman <nir@lichtman.org>
Link: https://lore.kernel.org/r/ZyYUgiPc8A8i_3FH@nirs-laptop

.
Signed-off-by: default avatarKees Cook <kees@kernel.org>
parent b6709dcd

fs/exec.c

+3 −3
Original line number Diff line number Diff line
@@ -1907,9 +1907,6 @@ static int do_execveat_common(int fd, struct filename *filename, 
	}



	retval = count(argv, MAX_ARG_STRINGS);

	if (retval == 0)

		pr_warn_once("process '%s' launched '%s' with NULL argv: empty string added\n",

			     current->comm, bprm->filename);

	if (retval < 0)

		goto out_free;

	bprm->argc = retval;
@@ -1947,6 +1944,9 @@ static int do_execveat_common(int fd, struct filename *filename, 
		if (retval < 0)

			goto out_free;

		bprm->argc = 1;



		pr_warn_once("process '%s' launched '%s' with NULL argv: empty string added\n",

			     current->comm, bprm->filename);

	}



	retval = bprm_execve(bprm);