exec: don't retry if request_module() fails
A separate one-liner for better documentation.
It doesn't make sense to retry if request_module() fails to exec
/sbin/modprobe, add the additional "request_module() < 0" check.
However, this logic still doesn't look exactly right:
1. It would be better to check "request_module() != 0", the user
space modprobe process should report the correct exit code.
But I didn't dare to add the user-visible change.
2. The whole ENOEXEC logic looks suboptimal. Suppose that we try
to exec a "#!path-to-unsupported-binary" script. In this case
request_module() + "retry" will be done twice: first by the
"depth == 1" code, and then again by the "depth == 0" caller
which doesn't make sense.
3. And note that in the case above bprm->buf was already changed
by load_script()->prepare_binprm(), so this looks even more
ugly.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Zach Levis <zml@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/exec.c b/fs/exec.c
index ba357e6..635b586 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1418,7 +1418,8 @@
if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&
printable(bprm->buf[2]) && printable(bprm->buf[3]))
return retval;
- request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2));
+ if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0)
+ return retval;
need_retry = false;
goto retry;
}