On Wed, 26 Feb 2020 13:49:27 +0100 Greg Kurz <[email protected]> wrote: > On Wed, 26 Feb 2020 06:10:38 -0600 > Shivaprasad G Bhat <[email protected]> wrote: > > > Fixes Coverity issue, > > CID 1419883: Error handling issues (CHECKED_RETURN) > > Calling "qemu_uuid_parse" without checking return value > > > > nvdimm_set_uuid() already verifies if the user provided uuid is valid or > > not. So, need to check for the validity during pre-plug validation again. > > > > Ok but since nvdimm_set_uuid() fills nvdimm->uuid why do you need to parse > the string again in the first place ? >
As discussed on slack, you can forget this remark. Using the QOM accessor is the way to go. > > As this a false positive in this case, assert if not valid to be safe. > > > > Reported-by: Coverity (CID 1419883) > > Signed-off-by: Shivaprasad G Bhat <[email protected]> > > --- > > hw/ppc/spapr_nvdimm.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/hw/ppc/spapr_nvdimm.c b/hw/ppc/spapr_nvdimm.c > > index 74eeb8bb74..051727536e 100644 > > --- a/hw/ppc/spapr_nvdimm.c > > +++ b/hw/ppc/spapr_nvdimm.c > > @@ -44,7 +44,7 @@ void spapr_nvdimm_validate_opts(NVDIMMDevice *nvdimm, > > uint64_t size, > > } > > > > uuidstr = object_property_get_str(OBJECT(nvdimm), NVDIMM_UUID_PROP, > > NULL); object_property_get_str() can theoretically return NULL and... > > - qemu_uuid_parse(uuidstr, &uuid); ... cause a segv in there because uuidstr will be dereferenced at some point without checking if it's NULL. AFAICT there are two scenarios that can cause object_property_get_str() to return NULL: - the property doesn't exist - the property isn't a string This can probably never happen with the current code base but we can't about future changes. In order to ensure we abort rather than segv, I'd pass &error_abort to object_property_get_str(). > > + g_assert(qemu_uuid_parse(uuidstr, &uuid) == 0); > > Like assert(), g_assert() is a macro that can be turned into a nop at > compile time: > > #ifdef G_DISABLE_ASSERT > #define g_assert_not_reached() G_STMT_START { (void) 0; } G_STMT_END > #define g_assert(expr) G_STMT_START { (void) 0; } G_STMT_END > #else /* !G_DISABLE_ASSERT */ > #define g_assert_not_reached() G_STMT_START { > g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, NULL); > } G_STMT_END > #define g_assert(expr) G_STMT_START { \ > if G_LIKELY (expr) ; else \ > g_assertion_message_expr > (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, \ > > #expr); \ > } G_STMT_END > #endif /* !G_DISABLE_ASSERT */ > > One should avoid putting expressions with side-effects in g_assert() because > the code may not be called at all if G_DISABLE_ASSERT is defined... > > > g_free(uuidstr); > > > > if (qemu_uuid_is_null(&uuid)) { > > ... and uuid would be uninitialized here :-\ > > If you need to use g_assert(), please do something like: > > ret = qemu_uuid_parse(uuidstr, &uuid); > g_assert(!ret); > > > > > >
