From 69fba378edcaffba7bc7d299fdee02e377069d30 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 29 Jan 2024 22:17:11 +0800 Subject: [PATCH] crypto: cbc - Ensure statesize is zero The cbc template should not be applied on stream ciphers, especially ones that have internal state. Enforce this by checking the state size when the instance is created. Reported-by: syzbot+050eeedd6c285d8c42f2@syzkaller.appspotmail.com Fixes: 47309ea13591 ("crypto: arc4 - Add internal state") Signed-off-by: Herbert Xu --- crypto/cbc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/crypto/cbc.c b/crypto/cbc.c index eedddef9ce40..e81918ca68b7 100644 --- a/crypto/cbc.c +++ b/crypto/cbc.c @@ -148,6 +148,9 @@ static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb) if (!is_power_of_2(inst->alg.co.base.cra_blocksize)) goto out_free_inst; + if (inst->alg.co.statesize) + goto out_free_inst; + inst->alg.encrypt = crypto_cbc_encrypt; inst->alg.decrypt = crypto_cbc_decrypt;