On Mon, Jan 29, 2024 at 04:55:30AM -0800, syzbot wrote: > > HEAD commit: 3a5879d495b2 Merge tag 'ata-6.8-rc2' of git://git.kernel.o.. > git tree: upstream > console+strace: https://syzkaller.appspot.com/x/log.txt?x=1683b6bbe80000 > kernel config: https://syzkaller.appspot.com/x/.config?x=bc36d99546fe9035 > dashboard link: https://syzkaller.appspot.com/bug?extid=050eeedd6c285d8c42f2 Thanks for the report. This is actually caused by the construction of cbc(arc4), which wasn't possible previously. Let's make it impossible again: ---8<--- 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@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 47309ea13591 ("crypto: arc4 - Add internal state") Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> 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; -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
