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LSM: SafeSetID: fix userns handling in securityfs

Looking at current_cred() in write handlers is bad form, stop doing that.

Also, let's just require that the write is coming from the initial user
namespace. Especially SAFESETID_WHITELIST_FLUSH requires privilege over all
namespaces, and SAFESETID_WHITELIST_ADD should probably require it as well.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Micah Morton <mortonm@chromium.org>
alistair/sunxi64-5.4-dsi
Jann Horn 2019-04-10 09:55:58 -07:00 committed by Micah Morton
parent 78ae7df96d
commit 71a98971b9
1 changed files with 3 additions and 3 deletions

View File

@ -59,8 +59,8 @@ static int parse_policy_line(
if (ret)
return ret;
*parent = make_kuid(current_user_ns(), parsed_parent);
*child = make_kuid(current_user_ns(), parsed_child);
*parent = make_kuid(file->f_cred->user_ns, parsed_parent);
*child = make_kuid(file->f_cred->user_ns, parsed_child);
if (!uid_valid(*parent) || !uid_valid(*child))
return -EINVAL;
@ -92,7 +92,7 @@ static ssize_t safesetid_file_write(struct file *file,
kuid_t child;
int ret;
if (!ns_capable(current_user_ns(), CAP_MAC_ADMIN))
if (!file_ns_capable(file, &init_user_ns, CAP_MAC_ADMIN))
return -EPERM;
if (*ppos != 0)