This is a note to let you know that I've just added the patch titled
crypto: arm64/neonbs - fix out-of-bounds access on short input
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
crypto-arm64-neonbs-fix-out-of-bounds-access-on-short-input.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1c0cf6d19690141002889d72622b90fc01562ce4 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ardb@xxxxxxxxxx>
Date: Fri, 23 Feb 2024 14:20:35 +0100
Subject: crypto: arm64/neonbs - fix out-of-bounds access on short input
From: Ard Biesheuvel <ardb@xxxxxxxxxx>
commit 1c0cf6d19690141002889d72622b90fc01562ce4 upstream.
The bit-sliced implementation of AES-CTR operates on blocks of 128
bytes, and will fall back to the plain NEON version for tail blocks or
inputs that are shorter than 128 bytes to begin with.
It will call straight into the plain NEON asm helper, which performs all
memory accesses in granules of 16 bytes (the size of a NEON register).
For this reason, the associated plain NEON glue code will copy inputs
shorter than 16 bytes into a temporary buffer, given that this is a rare
occurrence and it is not worth the effort to work around this in the asm
code.
The fallback from the bit-sliced NEON version fails to take this into
account, potentially resulting in out-of-bounds accesses. So clone the
same workaround, and use a temp buffer for short in/outputs.
Fixes: fc074e130051 ("crypto: arm64/aes-neonbs-ctr - fallback to plain NEON for final chunk")
Cc: <stable@xxxxxxxxxxxxxxx>
Reported-by: syzbot+f1ceaa1a09ab891e1934@xxxxxxxxxxxxxxxxxxxxxxxxx
Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/crypto/aes-neonbs-glue.c | 11 +++++++++++
1 file changed, 11 insertions(+)
--- a/arch/arm64/crypto/aes-neonbs-glue.c
+++ b/arch/arm64/crypto/aes-neonbs-glue.c
@@ -227,8 +227,19 @@ static int ctr_encrypt(struct skcipher_r
src += blocks * AES_BLOCK_SIZE;
}
if (nbytes && walk.nbytes == walk.total) {
+ u8 buf[AES_BLOCK_SIZE];
+ u8 *d = dst;
+
+ if (unlikely(nbytes < AES_BLOCK_SIZE))
+ src = dst = memcpy(buf + sizeof(buf) - nbytes,
+ src, nbytes);
+
neon_aes_ctr_encrypt(dst, src, ctx->enc, ctx->key.rounds,
nbytes, walk.iv);
+
+ if (unlikely(nbytes < AES_BLOCK_SIZE))
+ memcpy(d, dst, nbytes);
+
nbytes = 0;
}
kernel_neon_end();
Patches currently in stable-queue which might be from ardb@xxxxxxxxxx are
queue-6.1/efi-capsule-loader-fix-incorrect-allocation-size.patch
queue-6.1/crypto-arm64-neonbs-fix-out-of-bounds-access-on-short-input.patch
