| From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
| From: "Jason A. Donenfeld" <Jason@zx2c4.com> |
| Date: Thu, 6 Feb 2020 12:42:01 +0100 |
| Subject: [PATCH] crypto: chacha20poly1305 - prevent integer overflow on large |
| input |
| |
| commit c9cc0517bba9f0213f1e55172feceb99e5512daf upstream. |
| |
| This code assigns src_len (size_t) to sl (int), which causes problems |
| when src_len is very large. Probably nobody in the kernel should be |
| passing this much data to chacha20poly1305 all in one go anyway, so I |
| don't think we need to change the algorithm or introduce larger types |
| or anything. But we should at least error out early in this case and |
| print a warning so that we get reports if this does happen and can look |
| into why anybody is possibly passing it that much data or if they're |
| accidently passing -1 or similar. |
| |
| Fixes: d95312a3ccc0 ("crypto: lib/chacha20poly1305 - reimplement crypt_from_sg() routine") |
| Cc: Ard Biesheuvel <ardb@kernel.org> |
| Cc: stable@vger.kernel.org # 5.5+ |
| Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> |
| Acked-by: Ard Biesheuvel <ardb@kernel.org> |
| Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> |
| Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> |
| --- |
| lib/crypto/chacha20poly1305.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| --- a/lib/crypto/chacha20poly1305.c |
| +++ b/lib/crypto/chacha20poly1305.c |
| @@ -235,6 +235,9 @@ bool chacha20poly1305_crypt_sg_inplace(s |
| __le64 lens[2]; |
| } b __aligned(16); |
| |
| + if (WARN_ON(src_len > INT_MAX)) |
| + return false; |
| + |
| chacha_load_key(b.k, key); |
| |
| b.iv[0] = 0; |