| Message ID | 20220907162125.3950701-1-venture@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | crypto/block-luks: always set splitkeylen to 0 | expand |
On Wed, Sep 07, 2022 at 09:21:25AM -0700, Patrick Venture wrote: > This was caught by a sanitized build, that was perhaps oversensitive. > > Signed-off-by: Patrick Venture <venture@google.com> > --- > crypto/block-luks.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/crypto/block-luks.c b/crypto/block-luks.c > index f62be6836b..8633fb7e9f 100644 > --- a/crypto/block-luks.c > +++ b/crypto/block-luks.c > @@ -729,7 +729,7 @@ qcrypto_block_luks_store_key(QCryptoBlock *block, > QCryptoBlockLUKS *luks = block->opaque; > QCryptoBlockLUKSKeySlot *slot; > g_autofree uint8_t *splitkey = NULL; > - size_t splitkeylen; > + size_t splitkeylen = 0; > g_autofree uint8_t *slotkey = NULL; > g_autoptr(QCryptoCipher) cipher = NULL; > g_autoptr(QCryptoIVGen) ivgen = NULL; > @@ -901,7 +901,7 @@ qcrypto_block_luks_load_key(QCryptoBlock *block, > QCryptoBlockLUKS *luks = block->opaque; > const QCryptoBlockLUKSKeySlot *slot; > g_autofree uint8_t *splitkey = NULL; > - size_t splitkeylen; > + size_t splitkeylen = 0; > g_autofree uint8_t *possiblekey = NULL; > int rv; > g_autoptr(QCryptoCipher) cipher = NULL; > @@ -1147,7 +1147,7 @@ qcrypto_block_luks_erase_key(QCryptoBlock *block, > QCryptoBlockLUKS *luks = block->opaque; > QCryptoBlockLUKSKeySlot *slot; > g_autofree uint8_t *garbagesplitkey = NULL; > - size_t splitkeylen; > + size_t splitkeylen = 0; > size_t i; > Error *local_err = NULL; > int ret; In all three cases, splitkeylen is initialized a few lines later. In qcrypto_block_luks_store_key there is a 'goto cleanup' before the initialization. The 'cleanup' code can use 'splitkeylen', but only if 'splitkey != NULL' & this isn't possible if splitkeylen is uninitialized. The other two methods have no code path where splitkeylen can be used uninitialized. The tool is reporting non-existant problems AFAICT With regards, Daniel
On Wed, Sep 7, 2022 at 9:34 AM Daniel P. Berrangé <berrange@redhat.com> wrote: > On Wed, Sep 07, 2022 at 09:21:25AM -0700, Patrick Venture wrote: > > This was caught by a sanitized build, that was perhaps oversensitive. > > > > Signed-off-by: Patrick Venture <venture@google.com> > > --- > > crypto/block-luks.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/crypto/block-luks.c b/crypto/block-luks.c > > index f62be6836b..8633fb7e9f 100644 > > --- a/crypto/block-luks.c > > +++ b/crypto/block-luks.c > > @@ -729,7 +729,7 @@ qcrypto_block_luks_store_key(QCryptoBlock *block, > > QCryptoBlockLUKS *luks = block->opaque; > > QCryptoBlockLUKSKeySlot *slot; > > g_autofree uint8_t *splitkey = NULL; > > - size_t splitkeylen; > > + size_t splitkeylen = 0; > > g_autofree uint8_t *slotkey = NULL; > > g_autoptr(QCryptoCipher) cipher = NULL; > > g_autoptr(QCryptoIVGen) ivgen = NULL; > > @@ -901,7 +901,7 @@ qcrypto_block_luks_load_key(QCryptoBlock *block, > > QCryptoBlockLUKS *luks = block->opaque; > > const QCryptoBlockLUKSKeySlot *slot; > > g_autofree uint8_t *splitkey = NULL; > > - size_t splitkeylen; > > + size_t splitkeylen = 0; > > g_autofree uint8_t *possiblekey = NULL; > > int rv; > > g_autoptr(QCryptoCipher) cipher = NULL; > > @@ -1147,7 +1147,7 @@ qcrypto_block_luks_erase_key(QCryptoBlock *block, > > QCryptoBlockLUKS *luks = block->opaque; > > QCryptoBlockLUKSKeySlot *slot; > > g_autofree uint8_t *garbagesplitkey = NULL; > > - size_t splitkeylen; > > + size_t splitkeylen = 0; > > size_t i; > > Error *local_err = NULL; > > int ret; > > In all three cases, splitkeylen is initialized a few lines later. > > In qcrypto_block_luks_store_key there is a 'goto cleanup' before > the initialization. The 'cleanup' code can use 'splitkeylen', but > only if 'splitkey != NULL' & this isn't possible if splitkeylen is > uninitialized. > > The other two methods have no code path where splitkeylen can be > used uninitialized. > > The tool is reporting non-existant problems AFAICT > I'm 100% certain it is. I just needed to make the changes to get a sanitized build of Qemu to build. Presumably if someone else tries building qemu with `--enable-sanitizers` they'll have to make the same non-sense adjustment. > > With regards, > Daniel > -- > |: https://berrange.com -o- > https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- > https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- > https://www.instagram.com/dberrange :| > >
diff --git a/crypto/block-luks.c b/crypto/block-luks.c index f62be6836b..8633fb7e9f 100644 --- a/crypto/block-luks.c +++ b/crypto/block-luks.c @@ -729,7 +729,7 @@ qcrypto_block_luks_store_key(QCryptoBlock *block, QCryptoBlockLUKS *luks = block->opaque; QCryptoBlockLUKSKeySlot *slot; g_autofree uint8_t *splitkey = NULL; - size_t splitkeylen; + size_t splitkeylen = 0; g_autofree uint8_t *slotkey = NULL; g_autoptr(QCryptoCipher) cipher = NULL; g_autoptr(QCryptoIVGen) ivgen = NULL; @@ -901,7 +901,7 @@ qcrypto_block_luks_load_key(QCryptoBlock *block, QCryptoBlockLUKS *luks = block->opaque; const QCryptoBlockLUKSKeySlot *slot; g_autofree uint8_t *splitkey = NULL; - size_t splitkeylen; + size_t splitkeylen = 0; g_autofree uint8_t *possiblekey = NULL; int rv; g_autoptr(QCryptoCipher) cipher = NULL; @@ -1147,7 +1147,7 @@ qcrypto_block_luks_erase_key(QCryptoBlock *block, QCryptoBlockLUKS *luks = block->opaque; QCryptoBlockLUKSKeySlot *slot; g_autofree uint8_t *garbagesplitkey = NULL; - size_t splitkeylen; + size_t splitkeylen = 0; size_t i; Error *local_err = NULL; int ret;
This was caught by a sanitized build, that was perhaps oversensitive. Signed-off-by: Patrick Venture <venture@google.com> --- crypto/block-luks.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)