lkml.org 
[lkml]   [2017]   [Jul]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH 2/3] KEYS: DH: validate __spare field
From
Date
From: Eric Biggers <ebiggers@google.com>

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 <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---

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;
\
 
 \ /
  Last update: 2017-07-13 14:17    [W:0.042 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site