Commit 34a484d5 authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'selinux-pr-20180629' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux fix from Paul Moore:
 "One fairly straightforward patch to fix a longstanding issue where a
  process could stall while accessing files in selinuxfs and block
  everyone else due to a held mutex.

  The patch passes all our tests and looks to apply cleanly to your
  current tree"

* tag 'selinux-pr-20180629' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: move user accesses in selinuxfs out of locked regions
parents e6e5bec4 0da74120
......@@ -441,22 +441,16 @@ static int sel_release_policy(struct inode *inode, struct file *filp)
static ssize_t sel_read_policy(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
struct policy_load_memory *plm = filp->private_data;
int ret;
mutex_lock(&fsi->mutex);
ret = avc_has_perm(&selinux_state,
current_sid(), SECINITSID_SECURITY,
SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
if (ret)
goto out;
return ret;
ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
out:
mutex_unlock(&fsi->mutex);
return ret;
return simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
}
static vm_fault_t sel_mmap_policy_fault(struct vm_fault *vmf)
......@@ -1188,25 +1182,29 @@ static ssize_t sel_read_bool(struct file *filep, char __user *buf,
ret = -EINVAL;
if (index >= fsi->bool_num || strcmp(name,
fsi->bool_pending_names[index]))
goto out;
goto out_unlock;
ret = -ENOMEM;
page = (char *)get_zeroed_page(GFP_KERNEL);
if (!page)
goto out;
goto out_unlock;
cur_enforcing = security_get_bool_value(fsi->state, index);
if (cur_enforcing < 0) {
ret = cur_enforcing;
goto out;
goto out_unlock;
}
length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
fsi->bool_pending_values[index]);
ret = simple_read_from_buffer(buf, count, ppos, page, length);
out:
mutex_unlock(&fsi->mutex);
ret = simple_read_from_buffer(buf, count, ppos, page, length);
out_free:
free_page((unsigned long)page);
return ret;
out_unlock:
mutex_unlock(&fsi->mutex);
goto out_free;
}
static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
......@@ -1219,6 +1217,17 @@ static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
const char *name = filep->f_path.dentry->d_name.name;
if (count >= PAGE_SIZE)
return -ENOMEM;
/* No partial writes. */
if (*ppos != 0)
return -EINVAL;
page = memdup_user_nul(buf, count);
if (IS_ERR(page))
return PTR_ERR(page);
mutex_lock(&fsi->mutex);
length = avc_has_perm(&selinux_state,
......@@ -1233,22 +1242,6 @@ static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
fsi->bool_pending_names[index]))
goto out;
length = -ENOMEM;
if (count >= PAGE_SIZE)
goto out;
/* No partial writes. */
length = -EINVAL;
if (*ppos != 0)
goto out;
page = memdup_user_nul(buf, count);
if (IS_ERR(page)) {
length = PTR_ERR(page);
page = NULL;
goto out;
}
length = -EINVAL;
if (sscanf(page, "%d", &new_value) != 1)
goto out;
......@@ -1280,6 +1273,17 @@ static ssize_t sel_commit_bools_write(struct file *filep,
ssize_t length;
int new_value;
if (count >= PAGE_SIZE)
return -ENOMEM;
/* No partial writes. */
if (*ppos != 0)
return -EINVAL;
page = memdup_user_nul(buf, count);
if (IS_ERR(page))
return PTR_ERR(page);
mutex_lock(&fsi->mutex);
length = avc_has_perm(&selinux_state,
......@@ -1289,22 +1293,6 @@ static ssize_t sel_commit_bools_write(struct file *filep,
if (length)
goto out;
length = -ENOMEM;
if (count >= PAGE_SIZE)
goto out;
/* No partial writes. */
length = -EINVAL;
if (*ppos != 0)
goto out;
page = memdup_user_nul(buf, count);
if (IS_ERR(page)) {
length = PTR_ERR(page);
page = NULL;
goto out;
}
length = -EINVAL;
if (sscanf(page, "%d", &new_value) != 1)
goto out;
......
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