From: Eric Biggers <ebiggers@xxxxxxxxxx>
eCryptfs blindly casts the user-supplied key payload to a
'struct ecryptfs_auth_tok' without validating that the payload does, in
fact, have the size of a 'struct ecryptfs_auth_tok'. Fix it.
Fixes: 237fead61998 ("[PATCH] ecryptfs: fs/Makefile and fs/Kconfig")
Reviewed-by: James Morris <james.l.morris@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [v2.6.19+]
Cc: Michael Halcrow <mhalcrow@xxxxxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
Changed since v1: added Reviewed-by and resent in series with just the
ecryptfs patches. Can this please be taken through the ecryptfs tree?
fs/ecryptfs/ecryptfs_kernel.h | 6 ++++++
fs/ecryptfs/keystore.c | 4 ++++
2 files changed, 10 insertions(+)
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 3fbc0ff79699..945844d5f0ef 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -93,6 +93,9 @@ ecryptfs_get_encrypted_key_payload_data(struct key *key)
if (!payload)
return ERR_PTR(-EKEYREVOKED);
+ if (payload->payload_datalen != sizeof(struct ecryptfs_auth_tok))
+ return ERR_PTR(-EINVAL);
+
return (struct ecryptfs_auth_tok *)payload->payload_data;
}
@@ -129,6 +132,9 @@ ecryptfs_get_key_payload_data(struct key *key)
if (!ukp)
return ERR_PTR(-EKEYREVOKED);
+ if (ukp->datalen != sizeof(struct ecryptfs_auth_tok))
+ return ERR_PTR(-EINVAL);
+
return (struct ecryptfs_auth_tok *)ukp->data;
}
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index fa218cd64f74..95e20ab67df3 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -471,6 +471,10 @@ ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key,
(*auth_tok) = ecryptfs_get_key_payload_data(auth_tok_key);
if (IS_ERR(*auth_tok)) {
rc = PTR_ERR(*auth_tok);
+ if (rc == -EINVAL) {
+ ecryptfs_printk(KERN_ERR,
+ "Authentication token payload has wrong length\n");
+ }
*auth_tok = NULL;
goto out;
}
--
2.14.2.920.gcf0c67979c-goog
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