4.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Biggers ebiggers@google.com
commit d76c68109f37cb85b243a1cf0f40313afd2bae68 upstream.
pcrypt is using the old way of freeing instances, where the ->free() method specified in the 'struct crypto_template' is passed a pointer to the 'struct crypto_instance'. But the crypto_instance is being kfree()'d directly, which is incorrect because the memory was actually allocated as an aead_instance, which contains the crypto_instance at a nonzero offset. Thus, the wrong pointer was being kfree()'d.
Fix it by switching to the new way to free aead_instance's where the ->free() method is specified in the aead_instance itself.
Reported-by: syzbot syzkaller@googlegroups.com Fixes: 0496f56065e0 ("crypto: pcrypt - Add support for new AEAD interface") Signed-off-by: Eric Biggers ebiggers@google.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- crypto/pcrypt.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-)
--- a/crypto/pcrypt.c +++ b/crypto/pcrypt.c @@ -254,6 +254,14 @@ static void pcrypt_aead_exit_tfm(struct crypto_free_aead(ctx->child); }
+static void pcrypt_free(struct aead_instance *inst) +{ + struct pcrypt_instance_ctx *ctx = aead_instance_ctx(inst); + + crypto_drop_aead(&ctx->spawn); + kfree(inst); +} + static int pcrypt_init_instance(struct crypto_instance *inst, struct crypto_alg *alg) { @@ -319,6 +327,8 @@ static int pcrypt_create_aead(struct cry inst->alg.encrypt = pcrypt_aead_encrypt; inst->alg.decrypt = pcrypt_aead_decrypt;
+ inst->free = pcrypt_free; + err = aead_register_instance(tmpl, inst); if (err) goto out_drop_aead; @@ -349,14 +359,6 @@ static int pcrypt_create(struct crypto_t return -EINVAL; }
-static void pcrypt_free(struct crypto_instance *inst) -{ - struct pcrypt_instance_ctx *ctx = crypto_instance_ctx(inst); - - crypto_drop_aead(&ctx->spawn); - kfree(inst); -} - static int pcrypt_cpumask_change_notify(struct notifier_block *self, unsigned long val, void *data) { @@ -469,7 +471,6 @@ static void pcrypt_fini_padata(struct pa static struct crypto_template pcrypt_tmpl = { .name = "pcrypt", .create = pcrypt_create, - .free = pcrypt_free, .module = THIS_MODULE, };