From 55a01cab83b608bae6345b7e0e2fbecc142c1b2f Mon Sep 17 00:00:00 2001 From: Akihiko Odaki Date: Mon, 22 May 2023 20:47:37 +0900 Subject: [PATCH] crypto: Always initialize splitkeylen MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When _FORTIFY_SOURCE=2, glibc version is 2.35, and GCC version is 12.1.0, the compiler complains as follows: In file included from /usr/include/string.h:535, from /home/alarm/q/var/qemu/include/qemu/osdep.h:99, from ../crypto/block-luks.c:21: In function 'memset', inlined from 'qcrypto_block_luks_store_key' at ../crypto/block-luks.c:843:9: /usr/include/bits/string_fortified.h:59:10: error: 'splitkeylen' may be used uninitialized [-Werror=maybe-uninitialized] 59 | return __builtin___memset_chk (__dest, __ch, __len, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 60 | __glibc_objsize0 (__dest)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~ ../crypto/block-luks.c: In function 'qcrypto_block_luks_store_key': ../crypto/block-luks.c:699:12: note: 'splitkeylen' was declared here 699 | size_t splitkeylen; | ^~~~~~~~~~~ It seems the compiler cannot see that splitkeylen will not be used when splitkey is NULL. Suppress the warning by initializing splitkeylen even when splitkey stays NULL. Signed-off-by: Akihiko Odaki Signed-off-by: Daniel P. Berrangé --- crypto/block-luks.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/crypto/block-luks.c b/crypto/block-luks.c index 5688783ab1..2f59c3a625 100644 --- a/crypto/block-luks.c +++ b/crypto/block-luks.c @@ -706,14 +706,14 @@ qcrypto_block_luks_store_key(QCryptoBlock *block, assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); slot = &luks->header.key_slots[slot_idx]; + splitkeylen = luks->header.master_key_len * slot->stripes; + if (qcrypto_random_bytes(slot->salt, QCRYPTO_BLOCK_LUKS_SALT_LEN, errp) < 0) { goto cleanup; } - splitkeylen = luks->header.master_key_len * slot->stripes; - /* * Determine how many iterations are required to * hash the user password while consuming 1 second of compute