Revert "exec: load_script: don't blindly truncate shebang string"

commit cb5b020a8d upstream.

This reverts commit 8099b047ec.

It turns out that people do actually depend on the shebang string being
truncated, and on the fact that an interpreter (like perl) will often
just re-interpret it entirely to get the full argument list.

Reported-by: Samuel Dionne-Riel <samuel@dionne-riel.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Linus Torvalds 2019-02-14 15:02:18 -08:00 committed by Greg Kroah-Hartman
parent 557ac4e207
commit 56f88d7584

View File

@ -42,14 +42,10 @@ static int load_script(struct linux_binprm *bprm)
fput(bprm->file);
bprm->file = NULL;
for (cp = bprm->buf+2;; cp++) {
if (cp >= bprm->buf + BINPRM_BUF_SIZE)
return -ENOEXEC;
if (!*cp || (*cp == '\n'))
break;
}
bprm->buf[BINPRM_BUF_SIZE - 1] = '\0';
if ((cp = strchr(bprm->buf, '\n')) == NULL)
cp = bprm->buf+BINPRM_BUF_SIZE-1;
*cp = '\0';
while (cp > bprm->buf) {
cp--;
if ((*cp == ' ') || (*cp == '\t'))