commit bc2f61ad70971869b242fc1cb445b98bad50074a
Author: Tomas Mraz <tomas@openssl.org>
Date:   Mon Apr 17 16:51:20 2023 +0200

    aesv8-armx.pl: Avoid buffer overrread in AES-XTS decryption
    
    Original author: Nevine Ebeid (Amazon)
    Fixes: CVE-2023-1255
    
    The buffer overread happens on decrypts of 4 mod 5 sizes.
    Unless the memory just after the buffer is unmapped this is harmless.
    
    Reviewed-by: Paul Dale <pauli@openssl.org>
    Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
    (Merged from https://github.com/openssl/openssl/pull/20759)
    
    (cherry picked from commit 72dfe46550ee1f1bbfacd49f071419365bc23304)

diff --git a/crypto/aes/asm/aesv8-armx.pl b/crypto/aes/asm/aesv8-armx.pl
index ea74217317..efd3ccd1a4 100755
--- a/crypto/aes/asm/aesv8-armx.pl
+++ b/crypto/aes/asm/aesv8-armx.pl
@@ -3367,7 +3367,7 @@ $code.=<<___	if ($flavour =~ /64/);
 .align	4
 .Lxts_dec_tail4x:
 	add	$inp,$inp,#16
-	vld1.32	{$dat0},[$inp],#16
+	tst	$tailcnt,#0xf
 	veor	$tmp1,$dat1,$tmp0
 	vst1.8	{$tmp1},[$out],#16
 	veor	$tmp2,$dat2,$tmp2
@@ -3376,6 +3376,8 @@ $code.=<<___	if ($flavour =~ /64/);
 	veor	$tmp4,$dat4,$tmp4
 	vst1.8	{$tmp3-$tmp4},[$out],#32
 
+	b.eq	.Lxts_dec_abort
+	vld1.32	{$dat0},[$inp],#16
 	b	.Lxts_done
 .align	4
 .Lxts_outer_dec_tail:
