From 4f9dabfaf8df971f8a3b6aa324f8f817be38d538 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 13 Jul 2017 13:16:56 +0100 Subject: [PATCH] KEYS: DH: validate __spare field Syscalls must validate that their reserved arguments are zero and return EINVAL otherwise. Otherwise, it will be impossible to actually use them for anything in the future because existing programs may be passing garbage in. This is standard practice when adding new APIs. Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: James Morris --- security/keys/compat_dh.c | 2 ++ security/keys/dh.c | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/security/keys/compat_dh.c b/security/keys/compat_dh.c index a6a659b6bcb6..aa6b34cafe5f 100644 --- a/security/keys/compat_dh.c +++ b/security/keys/compat_dh.c @@ -33,6 +33,8 @@ long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params, kdfcopy.hashname = compat_ptr(compat_kdfcopy.hashname); kdfcopy.otherinfo = compat_ptr(compat_kdfcopy.otherinfo); kdfcopy.otherinfolen = compat_kdfcopy.otherinfolen; + memcpy(kdfcopy.__spare, compat_kdfcopy.__spare, + sizeof(kdfcopy.__spare)); return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy); } diff --git a/security/keys/dh.c b/security/keys/dh.c index 4755d4b4f945..d1ea9f325f94 100644 --- a/security/keys/dh.c +++ b/security/keys/dh.c @@ -266,6 +266,11 @@ long __keyctl_dh_compute(struct keyctl_dh_params __user *params, if (kdfcopy) { char *hashname; + if (memchr_inv(kdfcopy->__spare, 0, sizeof(kdfcopy->__spare))) { + ret = -EINVAL; + goto out1; + } + if (buflen > KEYCTL_KDF_MAX_OUTPUT_LEN || kdfcopy->otherinfolen > KEYCTL_KDF_MAX_OI_LEN) { ret = -EMSGSIZE; -- 2.30.2