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-rw-r--r--security/keys/trusted-keys/trusted_tpm2.c41
-rw-r--r--security/landlock/errata/abi-1.h16
-rw-r--r--security/landlock/fs.c46
-rw-r--r--security/landlock/ruleset.c12
-rw-r--r--security/landlock/ruleset.h2
5 files changed, 92 insertions, 25 deletions
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 8bc6efa8accb..a7ea4a1c3bed 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -268,7 +268,10 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
goto out_put;
}
- tpm_buf_append_name(chip, &buf, options->keyhandle, NULL);
+ rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL);
+ if (rc)
+ goto out;
+
tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_DECRYPT,
options->keyauth, TPM_DIGEST_SIZE);
@@ -316,7 +319,10 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
goto out;
}
- tpm_buf_fill_hmac_session(chip, &buf);
+ rc = tpm_buf_fill_hmac_session(chip, &buf);
+ if (rc)
+ goto out;
+
rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data");
rc = tpm_buf_check_hmac_response(chip, &buf, rc);
if (rc)
@@ -427,7 +433,10 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
return rc;
}
- tpm_buf_append_name(chip, &buf, options->keyhandle, NULL);
+ rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL);
+ if (rc)
+ goto out;
+
tpm_buf_append_hmac_session(chip, &buf, 0, options->keyauth,
TPM_DIGEST_SIZE);
@@ -439,7 +448,10 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
goto out;
}
- tpm_buf_fill_hmac_session(chip, &buf);
+ rc = tpm_buf_fill_hmac_session(chip, &buf);
+ if (rc)
+ goto out;
+
rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob");
rc = tpm_buf_check_hmac_response(chip, &buf, rc);
if (!rc)
@@ -469,8 +481,10 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
struct trusted_key_options *options,
u32 blob_handle)
{
+ struct tpm_header *head;
struct tpm_buf buf;
u16 data_len;
+ int offset;
u8 *data;
int rc;
@@ -484,7 +498,9 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
return rc;
}
- tpm_buf_append_name(chip, &buf, blob_handle, NULL);
+ rc = tpm_buf_append_name(chip, &buf, options->keyhandle, NULL);
+ if (rc)
+ goto out;
if (!options->policyhandle) {
tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_ENCRYPT,
@@ -505,11 +521,20 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
tpm2_buf_append_auth(&buf, options->policyhandle,
NULL /* nonce */, 0, 0,
options->blobauth, options->blobauth_len);
- tpm_buf_append_hmac_session_opt(chip, &buf, TPM2_SA_ENCRYPT,
- NULL, 0);
+ if (tpm2_chip_auth(chip)) {
+ tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_ENCRYPT, NULL, 0);
+ } else {
+ offset = buf.handles * 4 + TPM_HEADER_SIZE;
+ head = (struct tpm_header *)buf.data;
+ if (tpm_buf_length(&buf) == offset)
+ head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
+ }
}
- tpm_buf_fill_hmac_session(chip, &buf);
+ rc = tpm_buf_fill_hmac_session(chip, &buf);
+ if (rc)
+ goto out;
+
rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing");
rc = tpm_buf_check_hmac_response(chip, &buf, rc);
diff --git a/security/landlock/errata/abi-1.h b/security/landlock/errata/abi-1.h
new file mode 100644
index 000000000000..e8a2bff2e5b6
--- /dev/null
+++ b/security/landlock/errata/abi-1.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/**
+ * DOC: erratum_3
+ *
+ * Erratum 3: Disconnected directory handling
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This fix addresses an issue with disconnected directories that occur when a
+ * directory is moved outside the scope of a bind mount. The change ensures
+ * that evaluated access rights include both those from the disconnected file
+ * hierarchy down to its filesystem root and those from the related mount point
+ * hierarchy. This prevents access right widening through rename or link
+ * actions.
+ */
+LANDLOCK_ERRATUM(3)
diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index cee2b6f22c83..fe794875ad46 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -714,7 +714,8 @@ static void test_is_eacces_with_write(struct kunit *const test)
* is_access_to_paths_allowed - Check accesses for requests with a common path
*
* @domain: Domain to check against.
- * @path: File hierarchy to walk through.
+ * @path: File hierarchy to walk through. For refer checks, this would be
+ * the common mountpoint.
* @access_request_parent1: Accesses to check, once @layer_masks_parent1 is
* equal to @layer_masks_parent2 (if any). This is tied to the unique
* requested path for most actions, or the source in case of a refer action
@@ -837,7 +838,6 @@ static bool is_access_to_paths_allowed(
* restriction.
*/
while (true) {
- struct dentry *parent_dentry;
const struct landlock_rule *rule;
/*
@@ -909,21 +909,33 @@ jump_up:
break;
}
}
+
if (unlikely(IS_ROOT(walker_path.dentry))) {
- /*
- * Stops at disconnected root directories. Only allows
- * access to internal filesystems (e.g. nsfs, which is
- * reachable through /proc/<pid>/ns/<namespace>).
- */
- if (walker_path.mnt->mnt_flags & MNT_INTERNAL) {
+ if (likely(walker_path.mnt->mnt_flags & MNT_INTERNAL)) {
+ /*
+ * Stops and allows access when reaching disconnected root
+ * directories that are part of internal filesystems (e.g. nsfs,
+ * which is reachable through /proc/<pid>/ns/<namespace>).
+ */
allowed_parent1 = true;
allowed_parent2 = true;
+ break;
}
- break;
+
+ /*
+ * We reached a disconnected root directory from a bind mount.
+ * Let's continue the walk with the mount point we missed.
+ */
+ dput(walker_path.dentry);
+ walker_path.dentry = walker_path.mnt->mnt_root;
+ dget(walker_path.dentry);
+ } else {
+ struct dentry *const parent_dentry =
+ dget_parent(walker_path.dentry);
+
+ dput(walker_path.dentry);
+ walker_path.dentry = parent_dentry;
}
- parent_dentry = dget_parent(walker_path.dentry);
- dput(walker_path.dentry);
- walker_path.dentry = parent_dentry;
}
path_put(&walker_path);
@@ -1021,6 +1033,9 @@ static access_mask_t maybe_remove(const struct dentry *const dentry)
* file. While walking from @dir to @mnt_root, we record all the domain's
* allowed accesses in @layer_masks_dom.
*
+ * Because of disconnected directories, this walk may not reach @mnt_dir. In
+ * this case, the walk will continue to @mnt_dir after this call.
+ *
* This is similar to is_access_to_paths_allowed() but much simpler because it
* only handles walking on the same mount point and only checks one set of
* accesses.
@@ -1062,8 +1077,11 @@ static bool collect_domain_accesses(
break;
}
- /* We should not reach a root other than @mnt_root. */
- if (dir == mnt_root || WARN_ON_ONCE(IS_ROOT(dir)))
+ /*
+ * Stops at the mount point or the filesystem root for a disconnected
+ * directory.
+ */
+ if (dir == mnt_root || unlikely(IS_ROOT(dir)))
break;
parent_dentry = dget_parent(dir);
diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
index ce7940efea51..dfcdc19ea268 100644
--- a/security/landlock/ruleset.c
+++ b/security/landlock/ruleset.c
@@ -83,6 +83,10 @@ static void build_check_rule(void)
.num_layers = ~0,
};
+ /*
+ * Checks that .num_layers is large enough for at least
+ * LANDLOCK_MAX_NUM_LAYERS layers.
+ */
BUILD_BUG_ON(rule.num_layers < LANDLOCK_MAX_NUM_LAYERS);
}
@@ -290,6 +294,10 @@ static void build_check_layer(void)
.access = ~0,
};
+ /*
+ * Checks that .level and .access are large enough to contain their expected
+ * maximum values.
+ */
BUILD_BUG_ON(layer.level < LANDLOCK_MAX_NUM_LAYERS);
BUILD_BUG_ON(layer.access < LANDLOCK_MASK_ACCESS_FS);
}
@@ -644,8 +652,8 @@ bool landlock_unmask_layers(const struct landlock_rule *const rule,
bool is_empty;
/*
- * Records in @layer_masks which layer grants access to each
- * requested access.
+ * Records in @layer_masks which layer grants access to each requested
+ * access: bit cleared if the related layer grants access.
*/
is_empty = true;
for_each_set_bit(access_bit, &access_req, masks_array_size) {
diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
index 5da9a64f5af7..1a78cba662b2 100644
--- a/security/landlock/ruleset.h
+++ b/security/landlock/ruleset.h
@@ -27,7 +27,7 @@ struct landlock_hierarchy;
*/
struct landlock_layer {
/**
- * @level: Position of this layer in the layer stack.
+ * @level: Position of this layer in the layer stack. Starts from 1.
*/
u16 level;
/**
generated by cgit v1.2.3 (git 2.46.0) at 2025-12-08 01:47:08 +0000