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apparmor: move aa_file_perm() to use labels

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Signed-off-by: John Johansen <john.johansen@canonical.com>
This commit is contained in:
John Johansen
2017-06-09 14:59:51 -07:00
parent 290f458a4f
commit 190a95189e
3 changed files with 64 additions and 37 deletions
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48
security/apparmor/file.c
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@@ -23,6 +23,7 @@
#include "include/match.h"
#include "include/path.h"
#include "include/policy.h"
#include "include/label.h"
static u32 map_mask_to_chr_mask(u32 mask)
{
@@ -433,22 +434,55 @@ audit:
/**
* aa_file_perm - do permission revalidation check & audit for @file
* @op: operation being checked
* @profile: profile being enforced (NOT NULL)
* @label: label being enforced (NOT NULL)
* @file: file to revalidate access permissions on (NOT NULL)
* @request: requested permissions
*
* Returns: %0 if access allowed else error
*/
int aa_file_perm(const char *op, struct aa_profile *profile, struct file *file,
int aa_file_perm(const char *op, struct aa_label *label, struct file *file,
u32 request)
{
struct path_cond cond = {
.uid = file_inode(file)->i_uid,
.mode = file_inode(file)->i_mode
};
struct aa_file_ctx *fctx;
struct aa_label *flabel;
u32 denied;
int error = 0;
return aa_path_perm(op, profile, &file->f_path, PATH_DELEGATE_DELETED,
request, &cond);
AA_BUG(!label);
AA_BUG(!file);
fctx = file_ctx(file);
rcu_read_lock();
flabel = rcu_dereference(fctx->label);
AA_BUG(!flabel);
/* revalidate access, if task is unconfined, or the cached cred
* doesn't match or if the request is for more permissions than
* was granted.
*
* Note: the test for !unconfined(flabel) is to handle file
* delegation from unconfined tasks
*/
denied = request & ~fctx->allow;
if (unconfined(label) || unconfined(flabel) ||
(!denied && aa_label_is_subset(flabel, label)))
goto done;
/* TODO: label cross check */
if (file->f_path.mnt && path_mediated_fs(file->f_path.dentry))
error = aa_path_perm(op, labels_profile(label), &file->f_path,
PATH_DELEGATE_DELETED, request, &cond);
done:
rcu_read_unlock();
return error;
}
static void revalidate_tty(struct aa_label *label)
@@ -469,8 +503,7 @@ static void revalidate_tty(struct aa_label *label)
struct tty_file_private, list);
file = file_priv->file;
if (aa_file_perm(OP_INHERIT, labels_profile(label), file,
MAY_READ | MAY_WRITE))
if (aa_file_perm(OP_INHERIT, label, file, MAY_READ | MAY_WRITE))
drop_tty = 1;
}
spin_unlock(&tty->files_lock);
@@ -484,8 +517,7 @@ static int match_file(const void *p, struct file *file, unsigned int fd)
{
struct aa_label *label = (struct aa_label *)p;
if (aa_file_perm(OP_INHERIT, labels_profile(label), file,
aa_map_file_to_perms(file)))
if (aa_file_perm(OP_INHERIT, label, file, aa_map_file_to_perms(file)))
return fd + 1;
return 0;
}