[libvirt] [PATCH] util: fix crash when starting macvtap interfaces

This patch resolves https://bugzilla.redhat.com/show_bug.cgi?id=815270 The function virNetDevMacVLanVPortProfileRegisterCallback() takes an arg "virtPortProfile", and was checking it for non-NULL before using it. However, the prototype for virNetDevMacVLanPortProfileRegisterCallback had marked that arg with ATTRIBUTE_NONNULL(). Contrary to what one may think, ATTRIBUTE_NONNULL() does not provide any guarantee that an arg marked as such really is always non-null; the only effect to the code generated by gcc, is that gcc *assumes* it is non-NULL; this results in, for example, the check for a non-NULL value being optimized out. (Unfortunately, this code removal only occurs when optimization is enabled, and I am in the habit of doing local builds with optimization off to ease debugging, so the bug didn't show up in my earlier local testing). In general, virPortProfile might always be NULL, so it shouldn't be marked as ATTRIBUTE_NONNULL. One other function prototype made this same error, so this patch fixes it as well. --- src/util/virnetdevmacvlan.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/util/virnetdevmacvlan.h b/src/util/virnetdevmacvlan.h index 2299f1d..07d54e2 100644 --- a/src/util/virnetdevmacvlan.h +++ b/src/util/virnetdevmacvlan.h @@ -82,7 +82,7 @@ int virNetDevMacVLanRestartWithVPortProfile(const char *cr_ifname, virNetDevVPortProfilePtr virtPortProfile, enum virNetDevVPortProfileOp vmOp) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3) - ATTRIBUTE_NONNULL(4) ATTRIBUTE_NONNULL(5) ATTRIBUTE_RETURN_CHECK; + ATTRIBUTE_NONNULL(4) ATTRIBUTE_RETURN_CHECK; int virNetDevMacVLanVPortProfileRegisterCallback(const char *ifname, const unsigned char *macaddress , @@ -91,5 +91,5 @@ int virNetDevMacVLanVPortProfileRegisterCallback(const char *ifname, virNetDevVPortProfilePtr virtPortProfile, enum virNetDevVPortProfileOp vmOp) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3) -ATTRIBUTE_NONNULL(4) ATTRIBUTE_NONNULL(5) ATTRIBUTE_RETURN_CHECK; +ATTRIBUTE_NONNULL(4) ATTRIBUTE_RETURN_CHECK; #endif /* __UTIL_MACVTAP_H__ */ -- 1.7.10