From: Eric Biggers Date: Wed, 20 Dec 2017 22:28:25 +0000 (-0800) Subject: crypto: pcrypt - fix freeing pcrypt instances X-Git-Tag: android-x86-7.1-r1~1^2~45^2~18 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=c195a4c0230d7a1dafb53cdbd5eed4dea4493504;p=android-x86%2Fkernel.git crypto: pcrypt - fix freeing pcrypt instances 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 Fixes: 0496f56065e0 ("crypto: pcrypt - Add support for new AEAD interface") Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c index ee9cfb99fe25..f8ec3d4ba4a8 100644 --- a/crypto/pcrypt.c +++ b/crypto/pcrypt.c @@ -254,6 +254,14 @@ static void pcrypt_aead_exit_tfm(struct crypto_aead *tfm) 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 crypto_template *tmpl, struct rtattr **tb, 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_template *tmpl, struct rtattr **tb) 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 padata_pcrypt *pcrypt) static struct crypto_template pcrypt_tmpl = { .name = "pcrypt", .create = pcrypt_create, - .free = pcrypt_free, .module = THIS_MODULE, };