From a24611ea356c7f3f0ec926da11b9482ac1f414fd Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@google.com>
Date: Tue, 18 Jan 2022 16:13:05 -0800
Subject: [PATCH] crypto: rsa-pkcs1pad - fix buffer overread in pkcs1pad_verify_complete()
Git-commit: a24611ea356c7f3f0ec926da11b9482ac1f414fd
Patch-mainline: v5.18-rc1
References: bsc#1197601 git-fixes
Before checking whether the expected digest_info is present, we need to
check that there are enough bytes remaining.
Fixes: a49de377e051 ("crypto: Add hash param to pkcs1pad")
Cc: <stable@vger.kernel.org> # v4.6+
Cc: Tadeusz Struk <tadeusz.struk@linaro.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
crypto/rsa-pkcs1pad.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
index 6b556ddeb3a0..9d804831c8b3 100644
--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -476,6 +476,8 @@ static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
pos++;
if (digest_info) {
+ if (digest_info->size > dst_len - pos)
+ goto done;
if (crypto_memneq(out_buf + pos, digest_info->data,
digest_info->size))
goto done;
--
2.31.1