Re: [syzbot] [crypto?] KASAN: slab-out-of-bounds Read in arc4_crypt

[Edward Adam Davis]

please test slab-out-of-bounds Read in arc4_crypt

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 17cb8a20bde6
diff --git a/crypto/lskcipher.c b/crypto/lskcipher.c
index a06008e112f3..36968495607d 100644
--- a/crypto/lskcipher.c
+++ b/crypto/lskcipher.c
@@ -215,6 +215,12 @@ static int crypto_lskcipher_crypt_sg(struct skcipher_request *req,
 
 	flags = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 
+	printk("ivs: %p, v: %d, s: %u, ri: %p, wi: %p, %s\n", 
+		ivs, IS_ERR_OR_NULL(ivs), ivsize, req->iv, walk.iv, __func__);
+
+	if (IS_ERR_OR_NULL(ivs))
+		ivs = kzalloc(ivsize, GFP_KERNEL);
+
 	if (req->base.flags & CRYPTO_SKCIPHER_REQ_CONT)
 		flags |= CRYPTO_LSKCIPHER_FLAG_CONT;
 	else