From: Paul Moore <paul@xxxxxxxxxxxxxx>
[ Upstream commit 42c773238037c90b3302bf37a57ae3b5c3f6004a ]
Move our existing input sanity checking to the top of sel_write_load()
and add a check to ensure the buffer size is non-zero.
Move a local variable initialization from the declaration to before it
is used.
Minor style adjustments.
Reported-by: Sam Sun <samsun1006219@xxxxxxxxx>
Signed-off-by: Paul Moore <paul@xxxxxxxxxxxxxx>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxx>
---
security/selinux/selinuxfs.c | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 2c23a5a28608..54bc18e8164b 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -582,11 +582,18 @@ static ssize_t sel_write_load(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
- struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
+ struct selinux_fs_info *fsi;
struct selinux_load_state load_state;
ssize_t length;
void *data = NULL;
+ /* no partial writes */
+ if (*ppos)
+ return -EINVAL;
+ /* no empty policies */
+ if (!count)
+ return -EINVAL;
+
mutex_lock(&selinux_state.policy_mutex);
length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
@@ -594,26 +601,22 @@ static ssize_t sel_write_load(struct file *file, const char __user *buf,
if (length)
goto out;
- /* No partial writes. */
- length = -EINVAL;
- if (*ppos != 0)
- goto out;
-
- length = -ENOMEM;
data = vmalloc(count);
- if (!data)
+ if (!data) {
+ length = -ENOMEM;
goto out;
-
- length = -EFAULT;
- if (copy_from_user(data, buf, count) != 0)
+ }
+ if (copy_from_user(data, buf, count) != 0) {
+ length = -EFAULT;
goto out;
+ }
length = security_load_policy(data, count, &load_state);
if (length) {
pr_warn_ratelimited("SELinux: failed to load policy\n");
goto out;
}
-
+ fsi = file_inode(file)->i_sb->s_fs_info;
length = sel_make_policy_nodes(fsi, load_state.policy);
if (length) {
pr_warn_ratelimited("SELinux: failed to initialize selinuxfs\n");
@@ -622,13 +625,12 @@ static ssize_t sel_write_load(struct file *file, const char __user *buf,
}
selinux_policy_commit(&load_state);
-
length = count;
-
audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
"auid=%u ses=%u lsm=selinux res=1",
from_kuid(&init_user_ns, audit_get_loginuid(current)),
audit_get_sessionid(current));
+
out:
mutex_unlock(&selinux_state.policy_mutex);
vfree(data);
--
2.34.1
