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Patch "KEYS: Fix skcipher IV clobbering" has been added to the 4.7-stable tree

PATCH [email protected] 1 participant 1 message Sep 27, 2016

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Stable branch Security (LSM) Keys/keyrings Keys-encrypted
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This is a note to let you know that I've just added the patch titled

KEYS: Fix skcipher IV clobbering

to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
keys-fix-skcipher-iv-clobbering.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 456bee986e0a372ad4beed5d3cedb3622633d9df Mon Sep 17 00:00:00 2001

From: Herbert Xu <[email protected]>
Date: Tue, 20 Sep 2016 20:35:55 +0800
Subject: KEYS: Fix skcipher IV clobbering

From: Herbert Xu <[email protected]>

commit 456bee986e0a372ad4beed5d3cedb3622633d9df upstream.

The IV must not be modified by the skcipher operation so we need to duplicate it.

Fixes c3917fd9dfbc ("KEYS: Use skcipher")
Reported-by Mimi Zohar <[email protected]>
Signed-off-by Herbert Xu <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 security/keys/encrypted-keys/encrypted.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)
security/keys/encrypted-keys/encrypted.c +7 -4
@@ -29,6 +29,7 @@
 #include <linux/rcupdate.h>
 #include <linux/scatterlist.h>
 #include <linux/ctype.h>
+#include <crypto/aes.h>
 #include <crypto/hash.h>
 #include <crypto/sha.h>
 #include <crypto/skcipher.h>

@@ -478,6 +479,7 @@ static int derived_key_encrypt(struct en
 	struct crypto_skcipher *tfm;
 	struct skcipher_request *req;
 	unsigned int encrypted_datalen;
+	u8 iv[AES_BLOCK_SIZE];
 	unsigned int padlen;
 	char pad[16];
 	int ret;

@@ -500,8 +502,8 @@ static int derived_key_encrypt(struct en
 	sg_init_table(sg_out, 1);
 	sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen);
 
-	skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen,
-				   epayload->iv);
+	memcpy(iv, epayload->iv, sizeof(iv));
+	skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, iv);
 	ret = crypto_skcipher_encrypt(req);
 	tfm = crypto_skcipher_reqtfm(req);
 	skcipher_request_free(req);

@@ -581,6 +583,7 @@ static int derived_key_decrypt(struct en
 	struct crypto_skcipher *tfm;
 	struct skcipher_request *req;
 	unsigned int encrypted_datalen;
+	u8 iv[AES_BLOCK_SIZE];
 	char pad[16];
 	int ret;
 

@@ -599,8 +602,8 @@ static int derived_key_decrypt(struct en
 		   epayload->decrypted_datalen);
 	sg_set_buf(&sg_out[1], pad, sizeof pad);
 
-	skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen,
-				   epayload->iv);
+	memcpy(iv, epayload->iv, sizeof(iv));
+	skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, iv);
 	ret = crypto_skcipher_decrypt(req);
 	tfm = crypto_skcipher_reqtfm(req);
 	skcipher_request_free(req);

Patches currently in stable-queue which might be from [email protected] are

queue-4.7/crypto-echainiv-replace-chaining-with-multiplication.patch queue-4.7/crypto-arm64-aes-ctr-fix-null-dereference-in-tail-processing.patch queue-4.7/crypto-arm-aes-ctr-fix-null-dereference-in-tail-processing.patch queue-4.7/crypto-skcipher-fix-blkcipher-walk-oom-crash.patch queue-4.7/keys-fix-skcipher-iv-clobbering.patch