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authorDavid S. Miller <davem@davemloft.net>2016-02-23 00:09:14 -0500
committerDavid S. Miller <davem@davemloft.net>2016-02-23 00:09:14 -0500
commitb633353115e352d3c31c12d4c61978c810f05ea1 (patch)
tree055174a1b31a3e10fd2c505788fe6487b0028d00 /fs/ext4/crypto.c
parentb1d95ae5c5bd3deba84d00c4f83d7d0836b5936f (diff)
parentdea08e604408d0303e2332896c5fdd8c1f7d79a2 (diff)
downloadlinux-next-b633353115e352d3c31c12d4c61978c810f05ea1.tar.gz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: drivers/net/phy/bcm7xxx.c drivers/net/phy/marvell.c drivers/net/vxlan.c All three conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'fs/ext4/crypto.c')
-rw-r--r--fs/ext4/crypto.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index c8021208a7eb..38f7562489bb 100644
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -467,3 +467,59 @@ uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size)
return size;
return 0;
}
+
+/*
+ * Validate dentries for encrypted directories to make sure we aren't
+ * potentially caching stale data after a key has been added or
+ * removed.
+ */
+static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ struct inode *dir = d_inode(dentry->d_parent);
+ struct ext4_crypt_info *ci = EXT4_I(dir)->i_crypt_info;
+ int dir_has_key, cached_with_key;
+
+ if (!ext4_encrypted_inode(dir))
+ return 0;
+
+ if (ci && ci->ci_keyring_key &&
+ (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED) |
+ (1 << KEY_FLAG_DEAD))))
+ ci = NULL;
+
+ /* this should eventually be an flag in d_flags */
+ cached_with_key = dentry->d_fsdata != NULL;
+ dir_has_key = (ci != NULL);
+
+ /*
+ * If the dentry was cached without the key, and it is a
+ * negative dentry, it might be a valid name. We can't check
+ * if the key has since been made available due to locking
+ * reasons, so we fail the validation so ext4_lookup() can do
+ * this check.
+ *
+ * We also fail the validation if the dentry was created with
+ * the key present, but we no longer have the key, or vice versa.
+ */
+ if ((!cached_with_key && d_is_negative(dentry)) ||
+ (!cached_with_key && dir_has_key) ||
+ (cached_with_key && !dir_has_key)) {
+#if 0 /* Revalidation debug */
+ char buf[80];
+ char *cp = simple_dname(dentry, buf, sizeof(buf));
+
+ if (IS_ERR(cp))
+ cp = (char *) "???";
+ pr_err("revalidate: %s %p %d %d %d\n", cp, dentry->d_fsdata,
+ cached_with_key, d_is_negative(dentry),
+ dir_has_key);
+#endif
+ return 0;
+ }
+ return 1;
+}
+
+const struct dentry_operations ext4_encrypted_d_ops = {
+ .d_revalidate = ext4_d_revalidate,
+};