From b93332000206a6748fa7854991b9a221ffc73ec7 Mon Sep 17 00:00:00 2001 From: Tom Marshall Date: Wed, 25 Jan 2017 18:01:03 +0100 Subject: kernel: Only expose su when daemon is running It has been claimed that the PG implementation of 'su' has security vulnerabilities even when disabled. Unfortunately, the people that find these vulnerabilities often like to keep them private so they can profit from exploits while leaving users exposed to malicious hackers. In order to reduce the attack surface for vulnerabilites, it is therefore necessary to make 'su' completely inaccessible when it is not in use (except by the root and system users). Change-Id: I79716c72f74d0b7af34ec3a8054896c6559a181d --- fs/exec.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/exec.c') diff --git a/fs/exec.c b/fs/exec.c index 240a38eeb..e8a3ee5dd 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1572,6 +1572,11 @@ static int do_execve_common(const char *filename, if (retval < 0) goto out; + if (d_is_su(file->f_dentry) && capable(CAP_SYS_ADMIN)) { + current->flags |= PF_SU; + su_exec(); + } + /* execve succeeded */ current->fs->in_exec = 0; current->in_execve = 0; -- cgit v1.2.3